diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/apparmor/Makefile | 2 | ||||
| -rw-r--r-- | security/apparmor/policy.c | 24 | ||||
| -rw-r--r-- | security/device_cgroup.c | 101 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 18 |
4 files changed, 103 insertions, 42 deletions
diff --git a/security/apparmor/Makefile b/security/apparmor/Makefile index 7b3021c..5706b74 100644 --- a/security/apparmor/Makefile +++ b/security/apparmor/Makefile @@ -57,7 +57,7 @@ cmd_make-rlim = echo "static const char *const rlim_names[RLIM_NLIMITS] = {" \ $(obj)/capability.o : $(obj)/capability_names.h $(obj)/resource.o : $(obj)/rlim_names.h -$(obj)/capability_names.h : $(srctree)/include/linux/capability.h \ +$(obj)/capability_names.h : $(srctree)/include/uapi/linux/capability.h \ $(src)/Makefile $(call cmd,make-caps) $(obj)/rlim_names.h : $(srctree)/include/uapi/asm-generic/resource.h \ diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c index cf5fd22..8132003 100644 --- a/security/apparmor/policy.c +++ b/security/apparmor/policy.c @@ -724,6 +724,8 @@ fail: */ static void free_profile(struct aa_profile *profile) { + struct aa_profile *p; + AA_DEBUG("%s(%p)\n", __func__, profile); if (!profile) @@ -751,7 +753,27 @@ static void free_profile(struct aa_profile *profile) aa_put_dfa(profile->xmatch); aa_put_dfa(profile->policy.dfa); - aa_put_profile(profile->replacedby); + /* put the profile reference for replacedby, but not via + * put_profile(kref_put). + * replacedby can form a long chain that can result in cascading + * frees that blows the stack because kref_put makes a nested fn + * call (it looks like recursion, with free_profile calling + * free_profile) for each profile in the chain lp#1056078. + */ + for (p = profile->replacedby; p; ) { + if (atomic_dec_and_test(&p->base.count.refcount)) { + /* no more refs on p, grab its replacedby */ + struct aa_profile *next = p->replacedby; + /* break the chain */ + p->replacedby = NULL; + /* now free p, chain is broken */ + free_profile(p); + + /* follow up with next profile in the chain */ + p = next; + } else + break; + } kzfree(profile); } diff --git a/security/device_cgroup.c b/security/device_cgroup.c index 44dfc41..b08d20c 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -42,7 +42,10 @@ struct dev_exception_item { struct dev_cgroup { struct cgroup_subsys_state css; struct list_head exceptions; - bool deny_all; + enum { + DEVCG_DEFAULT_ALLOW, + DEVCG_DEFAULT_DENY, + } behavior; }; static inline struct dev_cgroup *css_to_devcgroup(struct cgroup_subsys_state *s) @@ -161,8 +164,8 @@ static void dev_exception_clean(struct dev_cgroup *dev_cgroup) struct dev_exception_item *ex, *tmp; list_for_each_entry_safe(ex, tmp, &dev_cgroup->exceptions, list) { - list_del(&ex->list); - kfree(ex); + list_del_rcu(&ex->list); + kfree_rcu(ex, rcu); } } @@ -182,13 +185,13 @@ static struct cgroup_subsys_state *devcgroup_create(struct cgroup *cgroup) parent_cgroup = cgroup->parent; if (parent_cgroup == NULL) - dev_cgroup->deny_all = false; + dev_cgroup->behavior = DEVCG_DEFAULT_ALLOW; else { parent_dev_cgroup = cgroup_to_devcgroup(parent_cgroup); mutex_lock(&devcgroup_mutex); ret = dev_exceptions_copy(&dev_cgroup->exceptions, &parent_dev_cgroup->exceptions); - dev_cgroup->deny_all = parent_dev_cgroup->deny_all; + dev_cgroup->behavior = parent_dev_cgroup->behavior; mutex_unlock(&devcgroup_mutex); if (ret) { kfree(dev_cgroup); @@ -260,7 +263,7 @@ static int devcgroup_seq_read(struct cgroup *cgroup, struct cftype *cft, * - List the exceptions in case the default policy is to deny * This way, the file remains as a "whitelist of devices" */ - if (devcgroup->deny_all == false) { + if (devcgroup->behavior == DEVCG_DEFAULT_ALLOW) { set_access(acc, ACC_MASK); set_majmin(maj, ~0); set_majmin(min, ~0); @@ -295,7 +298,7 @@ static int may_access(struct dev_cgroup *dev_cgroup, struct dev_exception_item *ex; bool match = false; - list_for_each_entry(ex, &dev_cgroup->exceptions, list) { + list_for_each_entry_rcu(ex, &dev_cgroup->exceptions, list) { if ((refex->type & DEV_BLOCK) && !(ex->type & DEV_BLOCK)) continue; if ((refex->type & DEV_CHAR) && !(ex->type & DEV_CHAR)) @@ -314,12 +317,12 @@ static int may_access(struct dev_cgroup *dev_cgroup, * In two cases we'll consider this new exception valid: * - the dev cgroup has its default policy to allow + exception list: * the new exception should *not* match any of the exceptions - * (!deny_all, !match) + * (behavior == DEVCG_DEFAULT_ALLOW, !match) * - the dev cgroup has its default policy to deny + exception list: * the new exception *should* match the exceptions - * (deny_all, match) + * (behavior == DEVCG_DEFAULT_DENY, match) */ - if (dev_cgroup->deny_all == match) + if ((dev_cgroup->behavior == DEVCG_DEFAULT_DENY) == match) return 1; return 0; } @@ -341,6 +344,19 @@ static int parent_has_perm(struct dev_cgroup *childcg, return may_access(parent, ex); } +/** + * may_allow_all - checks if it's possible to change the behavior to + * allow based on parent's rules. + * @parent: device cgroup's parent + * returns: != 0 in case it's allowed, 0 otherwise + */ +static inline int may_allow_all(struct dev_cgroup *parent) +{ + if (!parent) + return 1; + return parent->behavior == DEVCG_DEFAULT_ALLOW; +} + /* * Modify the exception list using allow/deny rules. * CAP_SYS_ADMIN is needed for this. It's at least separate from CAP_MKNOD @@ -358,13 +374,18 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, int filetype, const char *buffer) { const char *b; - char *endp; - int count; + char temp[12]; /* 11 + 1 characters needed for a u32 */ + int count, rc; struct dev_exception_item ex; + struct cgroup *p = devcgroup->css.cgroup; + struct dev_cgroup *parent = NULL; if (!capable(CAP_SYS_ADMIN)) return -EPERM; + if (p->parent) + parent = cgroup_to_devcgroup(p->parent); + memset(&ex, 0, sizeof(ex)); b = buffer; @@ -372,14 +393,21 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, case 'a': switch (filetype) { case DEVCG_ALLOW: - if (!parent_has_perm(devcgroup, &ex)) + if (!may_allow_all(parent)) return -EPERM; dev_exception_clean(devcgroup); - devcgroup->deny_all = false; + devcgroup->behavior = DEVCG_DEFAULT_ALLOW; + if (!parent) + break; + + rc = dev_exceptions_copy(&devcgroup->exceptions, + &parent->exceptions); + if (rc) + return rc; break; case DEVCG_DENY: dev_exception_clean(devcgroup); - devcgroup->deny_all = true; + devcgroup->behavior = DEVCG_DEFAULT_DENY; break; default: return -EINVAL; @@ -402,8 +430,16 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, ex.major = ~0; b++; } else if (isdigit(*b)) { - ex.major = simple_strtoul(b, &endp, 10); - b = endp; + memset(temp, 0, sizeof(temp)); + for (count = 0; count < sizeof(temp) - 1; count++) { + temp[count] = *b; + b++; + if (!isdigit(*b)) + break; + } + rc = kstrtou32(temp, 10, &ex.major); + if (rc) + return -EINVAL; } else { return -EINVAL; } @@ -416,8 +452,16 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, ex.minor = ~0; b++; } else if (isdigit(*b)) { - ex.minor = simple_strtoul(b, &endp, 10); - b = endp; + memset(temp, 0, sizeof(temp)); + for (count = 0; count < sizeof(temp) - 1; count++) { + temp[count] = *b; + b++; + if (!isdigit(*b)) + break; + } + rc = kstrtou32(temp, 10, &ex.minor); + if (rc) + return -EINVAL; } else { return -EINVAL; } @@ -452,7 +496,7 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, * an matching exception instead. And be silent about it: we * don't want to break compatibility */ - if (devcgroup->deny_all == false) { + if (devcgroup->behavior == DEVCG_DEFAULT_ALLOW) { dev_exception_rm(devcgroup, &ex); return 0; } @@ -463,7 +507,7 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, * an matching exception instead. And be silent about it: we * don't want to break compatibility */ - if (devcgroup->deny_all == true) { + if (devcgroup->behavior == DEVCG_DEFAULT_DENY) { dev_exception_rm(devcgroup, &ex); return 0; } @@ -533,10 +577,10 @@ struct cgroup_subsys devices_subsys = { * * returns 0 on success, -EPERM case the operation is not permitted */ -static int __devcgroup_check_permission(struct dev_cgroup *dev_cgroup, - short type, u32 major, u32 minor, +static int __devcgroup_check_permission(short type, u32 major, u32 minor, short access) { + struct dev_cgroup *dev_cgroup; struct dev_exception_item ex; int rc; @@ -547,6 +591,7 @@ static int __devcgroup_check_permission(struct dev_cgroup *dev_cgroup, ex.access = access; rcu_read_lock(); + dev_cgroup = task_devcgroup(current); rc = may_access(dev_cgroup, &ex); rcu_read_unlock(); @@ -558,7 +603,6 @@ static int __devcgroup_check_permission(struct dev_cgroup *dev_cgroup, int __devcgroup_inode_permission(struct inode *inode, int mask) { - struct dev_cgroup *dev_cgroup = task_devcgroup(current); short type, access = 0; if (S_ISBLK(inode->i_mode)) @@ -570,13 +614,12 @@ int __devcgroup_inode_permission(struct inode *inode, int mask) if (mask & MAY_READ) access |= ACC_READ; - return __devcgroup_check_permission(dev_cgroup, type, imajor(inode), - iminor(inode), access); + return __devcgroup_check_permission(type, imajor(inode), iminor(inode), + access); } int devcgroup_inode_mknod(int mode, dev_t dev) { - struct dev_cgroup *dev_cgroup = task_devcgroup(current); short type; if (!S_ISBLK(mode) && !S_ISCHR(mode)) @@ -587,7 +630,7 @@ int devcgroup_inode_mknod(int mode, dev_t dev) else type = DEV_CHAR; - return __devcgroup_check_permission(dev_cgroup, type, MAJOR(dev), - MINOR(dev), ACC_MKNOD); + return __devcgroup_check_permission(type, MAJOR(dev), MINOR(dev), + ACC_MKNOD); } diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 24ab414..61a5336 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2132,18 +2132,14 @@ static inline void flush_unauthorized_files(const struct cred *cred, return; devnull = dentry_open(&selinux_null, O_RDWR, cred); - if (!IS_ERR(devnull)) { - /* replace all the matching ones with this */ - do { - replace_fd(n - 1, get_file(devnull), 0); - } while ((n = iterate_fd(files, n, match_file, cred)) != 0); + if (IS_ERR(devnull)) + devnull = NULL; + /* replace all the matching ones with this */ + do { + replace_fd(n - 1, devnull, 0); + } while ((n = iterate_fd(files, n, match_file, cred)) != 0); + if (devnull) fput(devnull); - } else { - /* just close all the matching ones */ - do { - replace_fd(n - 1, NULL, 0); - } while ((n = iterate_fd(files, n, match_file, cred)) != 0); - } } /* |
