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* SELinux: Fix possible NULL pointer dereference in selinux_inode_permission()Steven Rostedt2014-01-122-3/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While running stress tests on adding and deleting ftrace instances I hit this bug: BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: selinux_inode_permission+0x85/0x160 PGD 63681067 PUD 7ddbe067 PMD 0 Oops: 0000 [#1] PREEMPT CPU: 0 PID: 5634 Comm: ftrace-test-mki Not tainted 3.13.0-rc4-test-00033-gd2a6dde-dirty #20 Hardware name: /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006 task: ffff880078375800 ti: ffff88007ddb0000 task.ti: ffff88007ddb0000 RIP: 0010:[<ffffffff812d8bc5>] [<ffffffff812d8bc5>] selinux_inode_permission+0x85/0x160 RSP: 0018:ffff88007ddb1c48 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000800000 RCX: ffff88006dd43840 RDX: 0000000000000001 RSI: 0000000000000081 RDI: ffff88006ee46000 RBP: ffff88007ddb1c88 R08: 0000000000000000 R09: ffff88007ddb1c54 R10: 6e6576652f6f6f66 R11: 0000000000000003 R12: 0000000000000000 R13: 0000000000000081 R14: ffff88006ee46000 R15: 0000000000000000 FS: 00007f217b5b6700(0000) GS:ffffffff81e21000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033^M CR2: 0000000000000020 CR3: 000000006a0fe000 CR4: 00000000000007f0 Call Trace: security_inode_permission+0x1c/0x30 __inode_permission+0x41/0xa0 inode_permission+0x18/0x50 link_path_walk+0x66/0x920 path_openat+0xa6/0x6c0 do_filp_open+0x43/0xa0 do_sys_open+0x146/0x240 SyS_open+0x1e/0x20 system_call_fastpath+0x16/0x1b Code: 84 a1 00 00 00 81 e3 00 20 00 00 89 d8 83 c8 02 40 f6 c6 04 0f 45 d8 40 f6 c6 08 74 71 80 cf 02 49 8b 46 38 4c 8d 4d cc 45 31 c0 <0f> b7 50 20 8b 70 1c 48 8b 41 70 89 d9 8b 78 04 e8 36 cf ff ff RIP selinux_inode_permission+0x85/0x160 CR2: 0000000000000020 Investigating, I found that the inode->i_security was NULL, and the dereference of it caused the oops. in selinux_inode_permission(): isec = inode->i_security; rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd); Note, the crash came from stressing the deletion and reading of debugfs files. I was not able to recreate this via normal files. But I'm not sure they are safe. It may just be that the race window is much harder to hit. What seems to have happened (and what I have traced), is the file is being opened at the same time the file or directory is being deleted. As the dentry and inode locks are not held during the path walk, nor is the inodes ref counts being incremented, there is nothing saving these structures from being discarded except for an rcu_read_lock(). The rcu_read_lock() protects against freeing of the inode, but it does not protect freeing of the inode_security_struct. Now if the freeing of the i_security happens with a call_rcu(), and the i_security field of the inode is not changed (it gets freed as the inode gets freed) then there will be no issue here. (Linus Torvalds suggested not setting the field to NULL such that we do not need to check if it is NULL in the permission check). Note, this is a hack, but it fixes the problem at hand. A real fix is to restructure the destroy_inode() to call all the destructor handlers from the RCU callback. But that is a major job to do, and requires a lot of work. For now, we just band-aid this bug with this fix (it works), and work on a more maintainable solution in the future. Link: http://lkml.kernel.org/r/20140109101932.0508dec7@gandalf.local.home Link: http://lkml.kernel.org/r/20140109182756.17abaaa8@gandalf.local.home Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* selinux: selinux_setprocattr()->ptrace_parent() needs rcu_read_lock()Oleg Nesterov2013-12-231-2/+2
| | | | | | | | | | | | | | | | selinux_setprocattr() does ptrace_parent(p) under task_lock(p), but task_struct->alloc_lock doesn't pin ->parent or ->ptrace, this looks confusing and triggers the "suspicious RCU usage" warning because ptrace_parent() does rcu_dereference_check(). And in theory this is wrong, spin_lock()->preempt_disable() doesn't necessarily imply rcu_read_lock() we need to access the ->parent. Reported-by: Evan McNabb <emcnabb@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paul Moore <pmoore@redhat.com>
* selinux: fix broken peer recv checkChad Hanson2013-12-231-1/+3
| | | | | | | | | | Fix a broken networking check. Return an error if peer recv fails. If secmark is active and the packet recv succeeds the peer recv error is ignored. Signed-off-by: Chad Hanson <chanson@trustedcs.com> Cc: stable@vger.kernel.org Signed-off-by: Paul Moore <pmoore@redhat.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-12-153-42/+165
|\ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull SELinux fixes from James Morris. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: selinux: process labeled IPsec TCP SYN-ACK packets properly in selinux_ip_postroute() selinux: look for IPsec labels on both inbound and outbound packets selinux: handle TCP SYN-ACK packets correctly in selinux_ip_postroute() selinux: handle TCP SYN-ACK packets correctly in selinux_ip_output() selinux: fix possible memory leak
| * Merge branch 'master' of git://git.infradead.org/users/pcmoore/selinux_fixes ↵James Morris2013-12-133-42/+165
| |\ | | | | | | | | | into for-linus
| | * selinux: process labeled IPsec TCP SYN-ACK packets properly in ↵Paul Moore2013-12-121-7/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | selinux_ip_postroute() Due to difficulty in arriving at the proper security label for TCP SYN-ACK packets in selinux_ip_postroute(), we need to check packets while/before they are undergoing XFRM transforms instead of waiting until afterwards so that we can determine the correct security label. Reported-by: Janak Desai <Janak.Desai@gtri.gatech.edu> Cc: stable@vger.kernel.org Signed-off-by: Paul Moore <pmoore@redhat.com>
| | * selinux: look for IPsec labels on both inbound and outbound packetsPaul Moore2013-12-123-14/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously selinux_skb_peerlbl_sid() would only check for labeled IPsec security labels on inbound packets, this patch enables it to check both inbound and outbound traffic for labeled IPsec security labels. Reported-by: Janak Desai <Janak.Desai@gtri.gatech.edu> Cc: stable@vger.kernel.org Signed-off-by: Paul Moore <pmoore@redhat.com>
| | * selinux: handle TCP SYN-ACK packets correctly in selinux_ip_postroute()Paul Moore2013-12-121-15/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In selinux_ip_postroute() we perform access checks based on the packet's security label. For locally generated traffic we get the packet's security label from the associated socket; this works in all cases except for TCP SYN-ACK packets. In the case of SYN-ACK packet's the correct security label is stored in the connection's request_sock, not the server's socket. Unfortunately, at the point in time when selinux_ip_postroute() is called we can't query the request_sock directly, we need to recreate the label using the same logic that originally labeled the associated request_sock. See the inline comments for more explanation. Reported-by: Janak Desai <Janak.Desai@gtri.gatech.edu> Tested-by: Janak Desai <Janak.Desai@gtri.gatech.edu> Cc: stable@vger.kernel.org Signed-off-by: Paul Moore <pmoore@redhat.com>
| | * selinux: handle TCP SYN-ACK packets correctly in selinux_ip_output()Paul Moore2013-12-121-2/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In selinux_ip_output() we always label packets based on the parent socket. While this approach works in almost all cases, it doesn't work in the case of TCP SYN-ACK packets when the correct label is not the label of the parent socket, but rather the label of the larval socket represented by the request_sock struct. Unfortunately, since the request_sock isn't queued on the parent socket until *after* the SYN-ACK packet is sent, we can't lookup the request_sock to determine the correct label for the packet; at this point in time the best we can do is simply pass/NF_ACCEPT the packet. It must be said that simply passing the packet without any explicit labeling action, while far from ideal, is not terrible as the SYN-ACK packet will inherit any IP option based labeling from the initial connection request so the label *should* be correct and all our access controls remain in place so we shouldn't have to worry about information leaks. Reported-by: Janak Desai <Janak.Desai@gtri.gatech.edu> Tested-by: Janak Desai <Janak.Desai@gtri.gatech.edu> Cc: stable@vger.kernel.org Signed-off-by: Paul Moore <pmoore@redhat.com>
| | * selinux: fix possible memory leakGeyslan G. Bem2013-12-041-4/+7
| | | | | | | | | | | | | | | | | | | | | Free 'ctx_str' when necessary. Signed-off-by: Geyslan G. Bem <geyslan@gmail.com> Signed-off-by: Paul Moore <pmoore@redhat.com>
| | * Merge tag 'v3.12'Paul Moore2013-11-2633-619/+1720
| | |\ | | | | | | | | | | | | Linux 3.12
* | | | Revert "selinux: consider filesystem subtype in policies"Linus Torvalds2013-12-152-60/+22
|/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 102aefdda4d8275ce7d7100bc16c88c74272b260. Tom London reports that it causes sync() to hang on Fedora rawhide: https://bugzilla.redhat.com/show_bug.cgi?id=1033965 and Josh Boyer bisected it down to this commit. Reverting the commit in the rawhide kernel fixes the problem. Eric Paris root-caused it to incorrect subtype matching in that commit breaking fuse, and has a tentative patch, but by now we're better off retrying this in 3.14 rather than playing with it any more. Reported-by: Tom London <selinux@gmail.com> Bisected-by: Josh Boyer <jwboyer@fedoraproject.org> Acked-by: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Anand Avati <avati@redhat.com> Cc: Paul Moore <paul@paul-moore.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge tag 'keys-devel-20131210' of ↵Linus Torvalds2013-12-123-17/+10
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull misc keyrings fixes from David Howells: "These break down into five sets: - A patch to error handling in the big_key type for huge payloads. If the payload is larger than the "low limit" and the backing store allocation fails, then big_key_instantiate() doesn't clear the payload pointers in the key, assuming them to have been previously cleared - but only one of them is. Unfortunately, the garbage collector still calls big_key_destroy() when sees one of the pointers with a weird value in it (and not NULL) which it then tries to clean up. - Three patches to fix the keyring type: * A patch to fix the hash function to correctly divide keyrings off from keys in the topology of the tree inside the associative array. This is only a problem if searching through nested keyrings - and only if the hash function incorrectly puts the a keyring outside of the 0 branch of the root node. * A patch to fix keyrings' use of the associative array. The __key_link_begin() function initially passes a NULL key pointer to assoc_array_insert() on the basis that it's holding a place in the tree whilst it does more allocation and stuff. This is only a problem when a node contains 16 keys that match at that level and we want to add an also matching 17th. This should easily be manufactured with a keyring full of keyrings (without chucking any other sort of key into the mix) - except for (a) above which makes it on average adding the 65th keyring. * A patch to fix searching down through nested keyrings, where any keyring in the set has more than 16 keyrings and none of the first keyrings we look through has a match (before the tree iteration needs to step to a more distal node). Test in keyutils test suite: http://git.kernel.org/cgit/linux/kernel/git/dhowells/keyutils.git/commit/?id=8b4ae963ed92523aea18dfbb8cab3f4979e13bd1 - A patch to fix the big_key type's use of a shmem file as its backing store causing audit messages and LSM check failures. This is done by setting S_PRIVATE on the file to avoid LSM checks on the file (access to the shmem file goes through the keyctl() interface and so is gated by the LSM that way). This isn't normally a problem if a key is used by the context that generated it - and it's currently only used by libkrb5. Test in keyutils test suite: http://git.kernel.org/cgit/linux/kernel/git/dhowells/keyutils.git/commit/?id=d9a53cbab42c293962f2f78f7190253fc73bd32e - A patch to add a generated file to .gitignore. - A patch to fix the alignment of the system certificate data such that it it works on s390. As I understand it, on the S390 arch, symbols must be 2-byte aligned because loading the address discards the least-significant bit" * tag 'keys-devel-20131210' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: KEYS: correct alignment of system_certificate_list content in assembly file Ignore generated file kernel/x509_certificate_list security: shmem: implement kernel private shmem inodes KEYS: Fix searching of nested keyrings KEYS: Fix multiple key add into associative array KEYS: Fix the keyring hash function KEYS: Pre-clear struct key on allocation
| * | | security: shmem: implement kernel private shmem inodesEric Paris2013-12-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have a problem where the big_key key storage implementation uses a shmem backed inode to hold the key contents. Because of this detail of implementation LSM checks are being done between processes trying to read the keys and the tmpfs backed inode. The LSM checks are already being handled on the key interface level and should not be enforced at the inode level (since the inode is an implementation detail, not a part of the security model) This patch implements a new function shmem_kernel_file_setup() which returns the equivalent to shmem_file_setup() only the underlying inode has S_PRIVATE set. This means that all LSM checks for the inode in question are skipped. It should only be used for kernel internal operations where the inode is not exposed to userspace without proper LSM checking. It is possible that some other users of shmem_file_setup() should use the new interface, but this has not been explored. Reproducing this bug is a little bit difficult. The steps I used on Fedora are: (1) Turn off selinux enforcing: setenforce 0 (2) Create a huge key k=`dd if=/dev/zero bs=8192 count=1 | keyctl padd big_key test-key @s` (3) Access the key in another context: runcon system_u:system_r:httpd_t:s0-s0:c0.c1023 keyctl print $k >/dev/null (4) Examine the audit logs: ausearch -m AVC -i --subject httpd_t | audit2allow If the last command's output includes a line that looks like: allow httpd_t user_tmpfs_t:file { open read }; There was an inode check between httpd and the tmpfs filesystem. With this patch no such denial will be seen. (NOTE! you should clear your audit log if you have tested for this previously) (Please return you box to enforcing) Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Hugh Dickins <hughd@google.com> cc: linux-mm@kvack.org
| * | | KEYS: Fix searching of nested keyringsDavid Howells2013-12-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a keyring contains more than 16 keyrings (the capacity of a single node in the associative array) then those keyrings are split over multiple nodes arranged as a tree. If search_nested_keyrings() is called to search the keyring then it will attempt to manually walk over just the 0 branch of the associative array tree where all the keyring links are stored. This works provided the key is found before the algorithm steps from one node containing keyrings to a child node or if there are sufficiently few keyring links that the keyrings are all in one node. However, if the algorithm does need to step from a node to a child node, it doesn't change the node pointer unless a shortcut also gets transited. This means that the algorithm will keep scanning the same node over and over again without terminating and without returning. To fix this, move the internal-pointer-to-node translation from inside the shortcut transit handler so that it applies it to node arrival as well. This can be tested by: r=`keyctl newring sandbox @s` for ((i=0; i<=16; i++)); do keyctl newring ring$i $r; done for ((i=0; i<=16; i++)); do keyctl add user a$i a %:ring$i; done for ((i=0; i<=16; i++)); do keyctl search $r user a$i; done for ((i=17; i<=20; i++)); do keyctl search $r user a$i; done The searches should all complete successfully (or with an error for 17-20), but instead one or more of them will hang. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Stephen Gallagher <sgallagh@redhat.com>
| * | | KEYS: Fix multiple key add into associative arrayDavid Howells2013-12-021-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If sufficient keys (or keyrings) are added into a keyring such that a node in the associative array's tree overflows (each node has a capacity N, currently 16) and such that all N+1 keys have the same index key segment for that level of the tree (the level'th nibble of the index key), then assoc_array_insert() calls ops->diff_objects() to indicate at which bit position the two index keys vary. However, __key_link_begin() passes a NULL object to assoc_array_insert() with the intention of supplying the correct pointer later before we commit the change. This means that keyring_diff_objects() is given a NULL pointer as one of its arguments which it does not expect. This results in an oops like the attached. With the previous patch to fix the keyring hash function, this can be forced much more easily by creating a keyring and only adding keyrings to it. Add any other sort of key and a different insertion path is taken - all 16+1 objects must want to cluster in the same node slot. This can be tested by: r=`keyctl newring sandbox @s` for ((i=0; i<=16; i++)); do keyctl newring ring$i $r; done This should work fine, but oopses when the 17th keyring is added. Since ops->diff_objects() is always called with the first pointer pointing to the object to be inserted (ie. the NULL pointer), we can fix the problem by changing the to-be-inserted object pointer to point to the index key passed into assoc_array_insert() instead. Whilst we're at it, we also switch the arguments so that they are the same as for ->compare_object(). BUG: unable to handle kernel NULL pointer dereference at 0000000000000088 IP: [<ffffffff81191ee4>] hash_key_type_and_desc+0x18/0xb0 ... RIP: 0010:[<ffffffff81191ee4>] hash_key_type_and_desc+0x18/0xb0 ... Call Trace: [<ffffffff81191f9d>] keyring_diff_objects+0x21/0xd2 [<ffffffff811f09ef>] assoc_array_insert+0x3b6/0x908 [<ffffffff811929a7>] __key_link_begin+0x78/0xe5 [<ffffffff81191a2e>] key_create_or_update+0x17d/0x36a [<ffffffff81192e0a>] SyS_add_key+0x123/0x183 [<ffffffff81400ddb>] tracesys+0xdd/0xe2 Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Stephen Gallagher <sgallagh@redhat.com>
| * | | KEYS: Fix the keyring hash functionDavid Howells2013-12-021-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The keyring hash function (used by the associative array) is supposed to clear the bottommost nibble of the index key (where the hash value resides) for keyrings and make sure it is non-zero for non-keyrings. This is done to make keyrings cluster together on one branch of the tree separately to other keys. Unfortunately, the wrong mask is used, so only the bottom two bits are examined and cleared and not the whole bottom nibble. This means that keys and keyrings can still be successfully searched for under most circumstances as the hash is consistent in its miscalculation, but if a keyring's associative array bottom node gets filled up then approx 75% of the keyrings will not be put into the 0 branch. The consequence of this is that a key in a keyring linked to by another keyring, ie. keyring A -> keyring B -> key may not be found if the search starts at keyring A and then descends into keyring B because search_nested_keyrings() only searches up the 0 branch (as it "knows" all keyrings must be there and not elsewhere in the tree). The fix is to use the right mask. This can be tested with: r=`keyctl newring sandbox @s` for ((i=0; i<=16; i++)); do keyctl newring ring$i $r; done for ((i=0; i<=16; i++)); do keyctl add user a$i a %:ring$i; done for ((i=0; i<=16; i++)); do keyctl search $r user a$i; done This creates a sandbox keyring, then creates 17 keyrings therein (labelled ring0..ring16). This causes the root node of the sandbox's associative array to overflow and for the tree to have extra nodes inserted. Each keyring then is given a user key (labelled aN for ringN) for us to search for. We then search for the user keys we added, starting from the sandbox. If working correctly, it should return the same ordered list of key IDs as for...keyctl add... did. Without this patch, it reports ENOKEY "Required key not available" for some of the keys. Just which keys get this depends as the kernel pointer to the key type forms part of the hash function. Reported-by: Nalin Dahyabhai <nalin@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Stephen Gallagher <sgallagh@redhat.com>
| * | | KEYS: Pre-clear struct key on allocationDavid Howells2013-12-021-7/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The second word of key->payload does not get initialised in key_alloc(), but the big_key type is relying on it having been cleared. The problem comes when big_key fails to instantiate a large key and doesn't then set the payload. The big_key_destroy() op is called from the garbage collector and this assumes that the dentry pointer stored in the second word will be NULL if instantiation did not complete. Therefore just pre-clear the entire struct key on allocation rather than trying to be clever and only initialising to 0 only those bits that aren't otherwise initialised. The lack of initialisation can lead to a bug report like the following if big_key failed to initialise its file: general protection fault: 0000 [#1] SMP Modules linked in: ... CPU: 0 PID: 51 Comm: kworker/0:1 Not tainted 3.10.0-53.el7.x86_64 #1 Hardware name: Dell Inc. PowerEdge 1955/0HC513, BIOS 1.4.4 12/09/2008 Workqueue: events key_garbage_collector task: ffff8801294f5680 ti: ffff8801296e2000 task.ti: ffff8801296e2000 RIP: 0010:[<ffffffff811b4a51>] dput+0x21/0x2d0 ... Call Trace: [<ffffffff811a7b06>] path_put+0x16/0x30 [<ffffffff81235604>] big_key_destroy+0x44/0x60 [<ffffffff8122dc4b>] key_gc_unused_keys.constprop.2+0x5b/0xe0 [<ffffffff8122df2f>] key_garbage_collector+0x1df/0x3c0 [<ffffffff8107759b>] process_one_work+0x17b/0x460 [<ffffffff8107834b>] worker_thread+0x11b/0x400 [<ffffffff81078230>] ? rescuer_thread+0x3e0/0x3e0 [<ffffffff8107eb00>] kthread+0xc0/0xd0 [<ffffffff8107ea40>] ? kthread_create_on_node+0x110/0x110 [<ffffffff815c4bec>] ret_from_fork+0x7c/0xb0 [<ffffffff8107ea40>] ? kthread_create_on_node+0x110/0x110 Reported-by: Patrik Kis <pkis@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Stephen Gallagher <sgallagh@redhat.com>
* | | | ima: properly free ima_template_entry structuresRoberto Sassu2013-12-023-5/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new templates management mechanism records information associated to an event into an array of 'ima_field_data' structures and makes it available through the 'template_data' field of the 'ima_template_entry' structure (the element of the measurements list created by IMA). Since 'ima_field_data' contains dynamically allocated data (which length varies depending on the data associated to a selected template field), it is not enough to just free the memory reserved for a 'ima_template_entry' structure if something goes wrong. This patch creates the new function ima_free_template_entry() which walks the array of 'ima_field_data' structures, frees the memory referenced by the 'data' pointer and finally the space reserved for the 'ima_template_entry' structure. Further, it replaces existing kfree() that have a pointer to an 'ima_template_entry' structure as argument with calls to the new function. Fixes: a71dc65: ima: switch to new template management mechanism Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
* | | | ima: Do not free 'entry' before it is initializedChristoph Paasch2013-12-021-1/+0
|/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 7bc5f447ce9d0 (ima: define new function ima_alloc_init_template() to API) moved the initialization of 'entry' in ima_add_boot_aggregate() a bit more below, after the if (ima_used_chip). So, 'entry' is not initialized while being inside this if-block. So, we should not attempt to free it. Found by Coverity (CID: 1131971) Fixes: 7bc5f447ce9d0 (ima: define new function ima_alloc_init_template() to API) Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
* | | ima: store address of template_fmt_copy in a pointer before calling strsepRoberto Sassu2013-11-301-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch stores the address of the 'template_fmt_copy' variable in a new variable, called 'template_fmt_ptr', so that the latter is passed as an argument of strsep() instead of the former. This modification is needed in order to correctly free the memory area referenced by 'template_fmt_copy' (strsep() modifies the pointer of the passed string). Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
* | | ima: make a copy of template_fmt in template_desc_init_fields()Roberto Sassu2013-11-251-7/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes a copy of the 'template_fmt' function argument so that the latter will not be modified by strsep(), which does the splitting by replacing the given separator with '\0'.  IMA: No TPM chip found, activating TPM-bypass!  Unable to handle kernel pointer dereference at virtual kernel address 0000000000842000  Oops: 0004 [#1] SMP  Modules linked in:  CPU: 3 PID: 1 Comm: swapper/0 Not tainted 3.12.0-rc2-00098-g3ce1217d6cd5 #17  task: 000000003ffa0000 ti: 000000003ff84000 task.ti: 000000003ff84000  Krnl PSW : 0704e00180000000 000000000044bf88 (strsep+0x7c/0xa0)             R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 EA:3  Krnl GPRS: 000000000000007c 000000000000007c 000000003ff87d90 0000000000821fd8             0000000000000000 000000000000007c 0000000000aa37e0 0000000000aa9008             0000000000000051 0000000000a114d8 0000000100000002 0000000000842bde             0000000000842bdf 00000000006f97f0 000000000040062c 000000003ff87cf0  Krnl Code: 000000000044bf7c: a7f4000a           brc     15,44bf90             000000000044bf80: b90200cc           ltgr    %r12,%r12            #000000000044bf84: a7840006           brc     8,44bf90            >000000000044bf88: 9200c000           mvi     0(%r12),0             000000000044bf8c: 41c0c001           la      %r12,1(%r12)             000000000044bf90: e3c020000024       stg     %r12,0(%r2)             000000000044bf96: b904002b           lgr     %r2,%r11             000000000044bf9a: ebbcf0700004       lmg     %r11,%r12,112(%r15)  Call Trace:  ([<00000000004005fe>] ima_init_template+0xa2/0x1bc)   [<0000000000a7c896>] ima_init+0x7a/0xa8   [<0000000000a7c938>] init_ima+0x24/0x40   [<00000000001000e8>] do_one_initcall+0x68/0x128   [<0000000000a4eb56>] kernel_init_freeable+0x20a/0x2b4   [<00000000006a1ff4>] kernel_init+0x30/0x178   [<00000000006b69fe>] kernel_thread_starter+0x6/0xc   [<00000000006b69f8>] kernel_thread_starter+0x0/0xc  Last Breaking-Event-Address:   [<000000000044bf42>] strsep+0x36/0xa0 Fixes commit: adf53a7 ima: new templates management mechanism Changelog v1: - make template_fmt 'const char *' (reported-by James Morris) - fix kstrdup memory leak (reported-by James Morris) Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* | | ima: do not send field length to userspace for digest of ima templateRoberto Sassu2013-11-253-5/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch defines a new value for the 'ima_show_type' enumerator (IMA_SHOW_BINARY_NO_FIELD_LEN) to prevent that the field length is transmitted through the 'binary_runtime_measurements' interface for the digest field of the 'ima' template. Fixes commit: 3ce1217 ima: define template fields library and new helpers Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* | | ima: do not include field length in template digest calc for ima templateRoberto Sassu2013-11-253-6/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To maintain compatibility with userspace tools, the field length must not be included in the template digest calculation for the 'ima' template. Fixes commit: a71dc65 ima: switch to new template management mechanism Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* | | Revert "ima: define '_ima' as a builtin 'trusted' keyring"Linus Torvalds2013-11-234-55/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 217091dd7a7a1bdac027ddb7c5a25f6ac0b8e241, which caused the following build error: security/integrity/digsig.c:70:5: error: redefinition of ‘integrity_init_keyring’ security/integrity/integrity.h:149:12: note: previous definition of ‘integrity_init_keyring’ w security/integrity/integrity.h:149:12: warning: ‘integrity_init_keyring’ defined but not used reported by Krzysztof Kolasa. Mimi says: "I made the classic mistake of requesting this patch to be upstreamed at the last second, rather than waiting until the next open window. At this point, the best course would probably be to revert the two commits and fix them for the next open window" Reported-by: Krzysztof Kolasa <kkolasa@winsoft.pl> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'for-linus2' of ↵Linus Torvalds2013-11-2165-1596/+3204
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "In this patchset, we finally get an SELinux update, with Paul Moore taking over as maintainer of that code. Also a significant update for the Keys subsystem, as well as maintenance updates to Smack, IMA, TPM, and Apparmor" and since I wanted to know more about the updates to key handling, here's the explanation from David Howells on that: "Okay. There are a number of separate bits. I'll go over the big bits and the odd important other bit, most of the smaller bits are just fixes and cleanups. If you want the small bits accounting for, I can do that too. (1) Keyring capacity expansion. KEYS: Consolidate the concept of an 'index key' for key access KEYS: Introduce a search context structure KEYS: Search for auth-key by name rather than target key ID Add a generic associative array implementation. KEYS: Expand the capacity of a keyring Several of the patches are providing an expansion of the capacity of a keyring. Currently, the maximum size of a keyring payload is one page. Subtract a small header and then divide up into pointers, that only gives you ~500 pointers on an x86_64 box. However, since the NFS idmapper uses a keyring to store ID mapping data, that has proven to be insufficient to the cause. Whatever data structure I use to handle the keyring payload, it can only store pointers to keys, not the keys themselves because several keyrings may point to a single key. This precludes inserting, say, and rb_node struct into the key struct for this purpose. I could make an rbtree of records such that each record has an rb_node and a key pointer, but that would use four words of space per key stored in the keyring. It would, however, be able to use much existing code. I selected instead a non-rebalancing radix-tree type approach as that could have a better space-used/key-pointer ratio. I could have used the radix tree implementation that we already have and insert keys into it by their serial numbers, but that means any sort of search must iterate over the whole radix tree. Further, its nodes are a bit on the capacious side for what I want - especially given that key serial numbers are randomly allocated, thus leaving a lot of empty space in the tree. So what I have is an associative array that internally is a radix-tree with 16 pointers per node where the index key is constructed from the key type pointer and the key description. This means that an exact lookup by type+description is very fast as this tells us how to navigate directly to the target key. I made the data structure general in lib/assoc_array.c as far as it is concerned, its index key is just a sequence of bits that leads to a pointer. It's possible that someone else will be able to make use of it also. FS-Cache might, for example. (2) Mark keys as 'trusted' and keyrings as 'trusted only'. KEYS: verify a certificate is signed by a 'trusted' key KEYS: Make the system 'trusted' keyring viewable by userspace KEYS: Add a 'trusted' flag and a 'trusted only' flag KEYS: Separate the kernel signature checking keyring from module signing These patches allow keys carrying asymmetric public keys to be marked as being 'trusted' and allow keyrings to be marked as only permitting the addition or linkage of trusted keys. Keys loaded from hardware during kernel boot or compiled into the kernel during build are marked as being trusted automatically. New keys can be loaded at runtime with add_key(). They are checked against the system keyring contents and if their signatures can be validated with keys that are already marked trusted, then they are marked trusted also and can thus be added into the master keyring. Patches from Mimi Zohar make this usable with the IMA keyrings also. (3) Remove the date checks on the key used to validate a module signature. X.509: Remove certificate date checks It's not reasonable to reject a signature just because the key that it was generated with is no longer valid datewise - especially if the kernel hasn't yet managed to set the system clock when the first module is loaded - so just remove those checks. (4) Make it simpler to deal with additional X.509 being loaded into the kernel. KEYS: Load *.x509 files into kernel keyring KEYS: Have make canonicalise the paths of the X.509 certs better to deduplicate The builder of the kernel now just places files with the extension ".x509" into the kernel source or build trees and they're concatenated by the kernel build and stuffed into the appropriate section. (5) Add support for userspace kerberos to use keyrings. KEYS: Add per-user_namespace registers for persistent per-UID kerberos caches KEYS: Implement a big key type that can save to tmpfs Fedora went to, by default, storing kerberos tickets and tokens in tmpfs. We looked at storing it in keyrings instead as that confers certain advantages such as tickets being automatically deleted after a certain amount of time and the ability for the kernel to get at these tokens more easily. To make this work, two things were needed: (a) A way for the tickets to persist beyond the lifetime of all a user's sessions so that cron-driven processes can still use them. The problem is that a user's session keyrings are deleted when the session that spawned them logs out and the user's user keyring is deleted when the UID is deleted (typically when the last log out happens), so neither of these places is suitable. I've added a system keyring into which a 'persistent' keyring is created for each UID on request. Each time a user requests their persistent keyring, the expiry time on it is set anew. If the user doesn't ask for it for, say, three days, the keyring is automatically expired and garbage collected using the existing gc. All the kerberos tokens it held are then also gc'd. (b) A key type that can hold really big tickets (up to 1MB in size). The problem is that Active Directory can return huge tickets with lots of auxiliary data attached. We don't, however, want to eat up huge tracts of unswappable kernel space for this, so if the ticket is greater than a certain size, we create a swappable shmem file and dump the contents in there and just live with the fact we then have an inode and a dentry overhead. If the ticket is smaller than that, we slap it in a kmalloc()'d buffer" * 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (121 commits) KEYS: Fix keyring content gc scanner KEYS: Fix error handling in big_key instantiation KEYS: Fix UID check in keyctl_get_persistent() KEYS: The RSA public key algorithm needs to select MPILIB ima: define '_ima' as a builtin 'trusted' keyring ima: extend the measurement list to include the file signature kernel/system_certificate.S: use real contents instead of macro GLOBAL() KEYS: fix error return code in big_key_instantiate() KEYS: Fix keyring quota misaccounting on key replacement and unlink KEYS: Fix a race between negating a key and reading the error set KEYS: Make BIG_KEYS boolean apparmor: remove the "task" arg from may_change_ptraced_domain() apparmor: remove parent task info from audit logging apparmor: remove tsk field from the apparmor_audit_struct apparmor: fix capability to not use the current task, during reporting Smack: Ptrace access check mode ima: provide hash algo info in the xattr ima: enable support for larger default filedata hash algorithms ima: define kernel parameter 'ima_template=' to change configured default ima: add Kconfig default measurement list template ...
| * | | KEYS: Fix keyring content gc scannerDavid Howells2013-11-142-51/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Key pointers stored in the keyring are marked in bit 1 to indicate if they point to a keyring. We need to strip off this bit before using the pointer when iterating over the keyring for the purpose of looking for links to garbage collect. This means that expirable keyrings aren't correctly expiring because the checker is seeing their key pointer with 2 added to it. Since the fix for this involves knowing about the internals of the keyring, key_gc_keyring() is moved to keyring.c and merged into keyring_gc(). This can be tested by: echo 2 >/proc/sys/kernel/keys/gc_delay keyctl timeout `keyctl add keyring qwerty "" @s` 2 cat /proc/keys sleep 5; cat /proc/keys which should see a keyring called "qwerty" appear in the session keyring and then disappear after it expires, and: echo 2 >/proc/sys/kernel/keys/gc_delay a=`keyctl get_persistent @s` b=`keyctl add keyring 0 "" $a` keyctl add user a a $b keyctl timeout $b 2 cat /proc/keys sleep 5; cat /proc/keys which should see a keyring called "0" with a key called "a" in it appear in the user's persistent keyring (which will be attached to the session keyring) and then both the "0" keyring and the "a" key should disappear when the "0" keyring expires. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Simo Sorce <simo@redhat.com>
| * | | KEYS: Fix error handling in big_key instantiationDavid Howells2013-11-131-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the big_key_instantiate() function we return 0 if kernel_write() returns us an error rather than returning an error. This can potentially lead to dentry_open() giving a BUG when called from big_key_read() with an unset tmpfile path. ------------[ cut here ]------------ kernel BUG at fs/open.c:798! ... RIP: 0010:[<ffffffff8119bbd1>] dentry_open+0xd1/0xe0 ... Call Trace: [<ffffffff812350c5>] big_key_read+0x55/0x100 [<ffffffff81231084>] keyctl_read_key+0xb4/0xe0 [<ffffffff81231e58>] SyS_keyctl+0xf8/0x1d0 [<ffffffff815bb799>] system_call_fastpath+0x16/0x1b Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Stephen Gallagher <sgallagh@redhat.com>
| * | | KEYS: Fix UID check in keyctl_get_persistent()David Howells2013-11-061-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the UID is specified by userspace when calling the KEYCTL_GET_PERSISTENT function and the process does not have the CAP_SETUID capability, then the function will return -EPERM if the current process's uid, suid, euid and fsuid all match the requested UID. This is incorrect. Fix it such that when a non-privileged caller requests a persistent keyring by a specific UID they can only request their own (ie. the specified UID matches either then process's UID or the process's EUID). This can be tested by logging in as the user and doing: keyctl get_persistent @p keyctl get_persistent @p `id -u` keyctl get_persistent @p 0 The first two should successfully print the same key ID. The third should do the same if called by UID 0 or indicate Operation Not Permitted otherwise. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Stephen Gallagher <sgallagh@redhat.com>
| * | | ima: define '_ima' as a builtin 'trusted' keyringMimi Zohar2013-10-314-1/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Require all keys added to the IMA keyring be signed by an existing trusted key on the system trusted keyring. Changelog: - define stub integrity_init_keyring() function (reported-by Fengguang Wu) - differentiate between regular and trusted keyring names. - replace printk with pr_info (D. Kasatkin) Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
| * | | ima: extend the measurement list to include the file signatureMimi Zohar2013-10-318-12/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch defines a new template called 'ima-sig', which includes the file signature in the template data, in addition to the file's digest and pathname. A template is composed of a set of fields. Associated with each field is an initialization and display function. This patch defines a new template field called 'sig', the initialization function ima_eventsig_init(), and the display function ima_show_template_sig(). This patch modifies the .field_init() function definition to include the 'security.ima' extended attribute and length. Changelog: - remove unused code (Dmitry Kasatkin) - avoid calling ima_write_template_field_data() unnecesarily (Roberto Sassu) - rename DATA_FMT_SIG to DATA_FMT_HEX - cleanup ima_eventsig_init() based on Roberto's comments Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
| * | | Merge branch 'keys-devel' of ↵James Morris2013-10-315-16/+25
| |\ \ \ | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into ra-next
| | * | | KEYS: fix error return code in big_key_instantiate()Wei Yongjun2013-10-301-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix to return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: David Howells <dhowells@redhat.com>
| | * | | KEYS: Fix keyring quota misaccounting on key replacement and unlinkDavid Howells2013-10-301-12/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a key is displaced from a keyring by a matching one, then four more bytes of quota are allocated to the keyring - despite the fact that the keyring does not change in size. Further, when a key is unlinked from a keyring, the four bytes of quota allocated the link isn't recovered and returned to the user's pool. The first can be tested by repeating: keyctl add big_key a fred @s cat /proc/key-users (Don't put it in a shell loop otherwise the garbage collector won't have time to clear the displaced keys, thus affecting the result). This was causing the kerberos keyring to run out of room fairly quickly. The second can be tested by: cat /proc/key-users a=`keyctl add user a a @s` cat /proc/key-users keyctl unlink $a sleep 1 # Give RCU a chance to delete the key cat /proc/key-users assuming no system activity that otherwise adds/removes keys, the amount of key data allocated should go up (say 40/20000 -> 47/20000) and then return to the original value at the end. Reported-by: Stephen Gallagher <sgallagh@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com>
| | * | | KEYS: Fix a race between negating a key and reading the error setDavid Howells2013-10-303-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | key_reject_and_link() marking a key as negative and setting the error with which it was negated races with keyring searches and other things that read that error. The fix is to switch the order in which the assignments are done in key_reject_and_link() and to use memory barriers. Kudos to Dave Wysochanski <dwysocha@redhat.com> and Scott Mayhew <smayhew@redhat.com> for tracking this down. This may be the cause of: BUG: unable to handle kernel NULL pointer dereference at 0000000000000070 IP: [<ffffffff81219011>] wait_for_key_construction+0x31/0x80 PGD c6b2c3067 PUD c59879067 PMD 0 Oops: 0000 [#1] SMP last sysfs file: /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map CPU 0 Modules linked in: ... Pid: 13359, comm: amqzxma0 Not tainted 2.6.32-358.20.1.el6.x86_64 #1 IBM System x3650 M3 -[7945PSJ]-/00J6159 RIP: 0010:[<ffffffff81219011>] wait_for_key_construction+0x31/0x80 RSP: 0018:ffff880c6ab33758 EFLAGS: 00010246 RAX: ffffffff81219080 RBX: 0000000000000000 RCX: 0000000000000002 RDX: ffffffff81219060 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff880c6ab33768 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff880adfcbce40 R13: ffffffffa03afb84 R14: ffff880adfcbce40 R15: ffff880adfcbce43 FS: 00007f29b8042700(0000) GS:ffff880028200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000070 CR3: 0000000c613dc000 CR4: 00000000000007f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process amqzxma0 (pid: 13359, threadinfo ffff880c6ab32000, task ffff880c610deae0) Stack: ffff880adfcbce40 0000000000000000 ffff880c6ab337b8 ffffffff81219695 <d> 0000000000000000 ffff880a000000d0 ffff880c6ab337a8 000000000000000f <d> ffffffffa03afb93 000000000000000f ffff88186c7882c0 0000000000000014 Call Trace: [<ffffffff81219695>] request_key+0x65/0xa0 [<ffffffffa03a0885>] nfs_idmap_request_key+0xc5/0x170 [nfs] [<ffffffffa03a0eb4>] nfs_idmap_lookup_id+0x34/0x80 [nfs] [<ffffffffa03a1255>] nfs_map_group_to_gid+0x75/0xa0 [nfs] [<ffffffffa039a9ad>] decode_getfattr_attrs+0xbdd/0xfb0 [nfs] [<ffffffff81057310>] ? __dequeue_entity+0x30/0x50 [<ffffffff8100988e>] ? __switch_to+0x26e/0x320 [<ffffffffa039ae03>] decode_getfattr+0x83/0xe0 [nfs] [<ffffffffa039b610>] ? nfs4_xdr_dec_getattr+0x0/0xa0 [nfs] [<ffffffffa039b69f>] nfs4_xdr_dec_getattr+0x8f/0xa0 [nfs] [<ffffffffa02dada4>] rpcauth_unwrap_resp+0x84/0xb0 [sunrpc] [<ffffffffa039b610>] ? nfs4_xdr_dec_getattr+0x0/0xa0 [nfs] [<ffffffffa02cf923>] call_decode+0x1b3/0x800 [sunrpc] [<ffffffff81096de0>] ? wake_bit_function+0x0/0x50 [<ffffffffa02cf770>] ? call_decode+0x0/0x800 [sunrpc] [<ffffffffa02d99a7>] __rpc_execute+0x77/0x350 [sunrpc] [<ffffffff81096c67>] ? bit_waitqueue+0x17/0xd0 [<ffffffffa02d9ce1>] rpc_execute+0x61/0xa0 [sunrpc] [<ffffffffa02d03a5>] rpc_run_task+0x75/0x90 [sunrpc] [<ffffffffa02d04c2>] rpc_call_sync+0x42/0x70 [sunrpc] [<ffffffffa038ff80>] _nfs4_call_sync+0x30/0x40 [nfs] [<ffffffffa038836c>] _nfs4_proc_getattr+0xac/0xc0 [nfs] [<ffffffff810aac87>] ? futex_wait+0x227/0x380 [<ffffffffa038b856>] nfs4_proc_getattr+0x56/0x80 [nfs] [<ffffffffa0371403>] __nfs_revalidate_inode+0xe3/0x220 [nfs] [<ffffffffa037158e>] nfs_revalidate_mapping+0x4e/0x170 [nfs] [<ffffffffa036f147>] nfs_file_read+0x77/0x130 [nfs] [<ffffffff811811aa>] do_sync_read+0xfa/0x140 [<ffffffff81096da0>] ? autoremove_wake_function+0x0/0x40 [<ffffffff8100bb8e>] ? apic_timer_interrupt+0xe/0x20 [<ffffffff8100b9ce>] ? common_interrupt+0xe/0x13 [<ffffffff81228ffb>] ? selinux_file_permission+0xfb/0x150 [<ffffffff8121bed6>] ? security_file_permission+0x16/0x20 [<ffffffff81181a95>] vfs_read+0xb5/0x1a0 [<ffffffff81181bd1>] sys_read+0x51/0x90 [<ffffffff810dc685>] ? __audit_syscall_exit+0x265/0x290 [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b Signed-off-by: David Howells <dhowells@redhat.com> cc: Dave Wysochanski <dwysocha@redhat.com> cc: Scott Mayhew <smayhew@redhat.com>
| | * | | KEYS: Make BIG_KEYS booleanJosh Boyer2013-10-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Having the big_keys functionality as a module is very marginally useful. The userspace code that would use this functionality will get odd error messages from the keys layer if the module isn't loaded. The code itself is fairly small, so just have this as a boolean option and not a tristate. Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org> Signed-off-by: David Howells <dhowells@redhat.com>
| * | | | apparmor: remove the "task" arg from may_change_ptraced_domain()Oleg Nesterov2013-10-291-8/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unless task == current ptrace_parent(task) is not safe even under rcu_read_lock() and most of the current users are not right. So may_change_ptraced_domain(task) looks wrong as well. However it is always called with task == current so the code is actually fine. Remove this argument to make this fact clear. Note: perhaps we should simply kill ptrace_parent(), it buys almost nothing. And it is obviously racy, perhaps this should be fixed. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
| * | | | apparmor: remove parent task info from audit loggingJohn Johansen2013-10-292-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The reporting of the parent task info is a vestage from old versions of apparmor. The need for this information was removed by unique null- profiles before apparmor was upstreamed so remove this info from logging. Signed-off-by: John Johansen <john.johansen@canonical.com>
| * | | | apparmor: remove tsk field from the apparmor_audit_structJohn Johansen2013-10-291-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that aa_capabile no longer sets the task field it can be removed and the lsm_audit version of the field can be used. Signed-off-by: John Johansen <john.johansen@canonical.com>
| * | | | apparmor: fix capability to not use the current task, during reportingJohn Johansen2013-10-296-22/+15
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | Mediation is based off of the cred but auditing includes the current task which may not be related to the actual request. Signed-off-by: John Johansen <john.johansen@canonical.com>
| * | | Merge branch 'smack-for-3.13' of git://git.gitorious.org/smack-next/kernel ↵James Morris2013-10-304-9/+34
| |\ \ \ | | | | | | | | | | | | | | | into ra-next
| | * | | Smack: Ptrace access check modeCasey Schaufler2013-10-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the ptrace security hooks were split the addition of a mode parameter was not taken advantage of in the Smack ptrace access check. This changes the access check from always looking for read and write access to using the passed mode. This will make use of /proc much happier. Targeted for git://git.gitorious.org/smack-next/kernel.git Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
| | * | | Smack: Implement lock security modeCasey Schaufler2013-10-184-8/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux file locking does not follow the same rules as other mechanisms. Even though it is a write operation a process can set a read lock on files which it has open only for read access. Two programs with read access to a file can use read locks to communicate. This is not acceptable in a Mandatory Access Control environment. Smack treats setting a read lock as the write operation that it is. Unfortunately, many programs assume that setting a read lock is a read operation. These programs are unhappy in the Smack environment. This patch introduces a new access mode (lock) to address this problem. A process with lock access to a file can set a read lock. A process with write access to a file can set a read lock or a write lock. This prevents a situation where processes are granted write access just so they can set read locks. Targeted for git://git.gitorious.org/smack-next/kernel.git Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
| * | | | ima: provide hash algo info in the xattrDmitry Kasatkin2013-10-262-15/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All files labeled with 'security.ima' hashes, are hashed using the same hash algorithm. Changing from one hash algorithm to another, requires relabeling the filesystem. This patch defines a new xattr type, which includes the hash algorithm, permitting different files to be hashed with different algorithms. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
| * | | | ima: enable support for larger default filedata hash algorithmsMimi Zohar2013-10-262-2/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The IMA measurement list contains two hashes - a template data hash and a filedata hash. The template data hash is committed to the TPM, which is limited, by the TPM v1.2 specification, to 20 bytes. The filedata hash is defined as 20 bytes as well. Now that support for variable length measurement list templates was added, the filedata hash is not limited to 20 bytes. This patch adds Kconfig support for defining larger default filedata hash algorithms and replacing the builtin default with one specified on the kernel command line. <uapi/linux/hash_info.h> contains a list of hash algorithms. The Kconfig default hash algorithm is a subset of this list, but any hash algorithm included in the list can be specified at boot, using the 'ima_hash=' kernel command line option. Changelog v2: - update Kconfig Changelog: - support hashes that are configured - use generic HASH_ALGO_ definitions - add Kconfig support - hash_setup must be called only once (Dmitry) - removed trailing whitespaces (Roberto Sassu) Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
| * | | | ima: define kernel parameter 'ima_template=' to change configured defaultRoberto Sassu2013-10-261-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch allows users to specify from the kernel command line the template descriptor, among those defined, that will be used to generate and display measurement entries. If an user specifies a wrong template, IMA reverts to the template descriptor set in the kernel configuration. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
| * | | | ima: add Kconfig default measurement list templateMimi Zohar2013-10-262-2/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a Kconfig option to select the default IMA measurement list template. The 'ima' template limited the filedata hash to 20 bytes and the pathname to 255 charaters. The 'ima-ng' measurement list template permits larger hash digests and longer pathnames. Changelog: - keep 'select CRYPTO_HASH_INFO' in 'config IMA' section (Kconfig) (Roberto Sassu); - removed trailing whitespaces (Roberto Sassu). - Lindent fixes Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
| * | | | ima: defer determining the appraisal hash algorithm for 'ima' templateRoberto Sassu2013-10-261-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The same hash algorithm should be used for calculating the file data hash for the IMA measurement list, as for appraising the file data integrity. (The appraise hash algorithm is stored in the 'security.ima' extended attribute.) The exception is when the reference file data hash digest, stored in the extended attribute, is larger than the one supported by the template. In this case, the file data hash needs to be calculated twice, once for the measurement list and, again, for appraisal. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
| * | | | ima: add audit log support for larger hashesMimi Zohar2013-10-261-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Different files might be signed based on different hash algorithms. This patch prefixes the audit log measurement hash with the hash algorithm. Changelog: - use generic HASH_ALGO defintions - use ':' as delimiter between the hash algorithm and the digest (Roberto Sassu) - always include the hash algorithm used when audit-logging a measurement Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Peter Moody <pmoody@google.com>
| * | | | ima: switch to new template management mechanismRoberto Sassu2013-10-255-97/+107
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch performs the switch to the new template mechanism by modifying the functions ima_alloc_init_template(), ima_measurements_show() and ima_ascii_measurements_show(). The old function ima_template_show() was removed as it is no longer needed. Also, if the template descriptor used to generate a measurement entry is not 'ima', the whole length of field data stored for an entry is provided before the data itself through the binary_runtime_measurement interface. Changelog: - unnecessary to use strncmp() (Mimi Zohar) - create new variable 'field' in ima_alloc_init_template() (Roberto Sassu) - use GFP_NOFS flag in ima_alloc_init_template() (Roberto Sassu) - new variable 'num_fields' in ima_store_template() (Roberto Sassu, proposed by Mimi Zohar) - rename ima_calc_buffer_hash/template_hash() to ima_calc_field_array_hash(), something more generic (Mimi, requested by Dmitry) - sparse error fix - Fengguang Wu - fix lindent warnings - always include the field length in the template data length - include the template field length variable size in the template data length - include both the template field data and field length in the template digest calculation. Simplifies verifying the template digest. (Mimi) Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
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