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| author | Eric Paris <eparis@redhat.com> | 2009-07-31 12:54:05 -0400 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2009-08-06 09:02:21 +1000 |
| commit | 84336d1a77ccd2c06a730ddd38e695c2324a7386 (patch) | |
| tree | 9eeb414eff58e5b7165daa36c2ce3c2e7422632b /security | |
| parent | 7c73875e7dda627040b12c19b01db634fa7f0fd1 (diff) | |
| download | op-kernel-dev-84336d1a77ccd2c06a730ddd38e695c2324a7386.zip op-kernel-dev-84336d1a77ccd2c06a730ddd38e695c2324a7386.tar.gz | |
SELinux: call cap_file_mmap in selinux_file_mmap
Currently SELinux does not check CAP_SYS_RAWIO in the file_mmap hook. This
means there is no DAC check on the ability to mmap low addresses in the
memory space. This function adds the DAC check for CAP_SYS_RAWIO while
maintaining the selinux check on mmap_zero. This means that processes
which need to mmap low memory will need CAP_SYS_RAWIO and mmap_zero but will
NOT need the SELinux sys_rawio capability.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security')
| -rw-r--r-- | security/selinux/hooks.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index e65677d..8a78f58 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3034,9 +3034,21 @@ static int selinux_file_mmap(struct file *file, unsigned long reqprot, int rc = 0; u32 sid = current_sid(); - if (addr < mmap_min_addr) + /* + * notice that we are intentionally putting the SELinux check before + * the secondary cap_file_mmap check. This is such a likely attempt + * at bad behaviour/exploit that we always want to get the AVC, even + * if DAC would have also denied the operation. + */ + if (addr < mmap_min_addr) { rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, MEMPROTECT__MMAP_ZERO, NULL); + if (rc) + return rc; + } + + /* do DAC check on address space usage */ + rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only); if (rc || addr_only) return rc; |
