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BugLink: http://bugs.launchpad.net/bugs/1235977 The profile introspection seq file has a locking bug when policy is viewed from a virtual root (task in a policy namespace), introspection from the real root is not affected. The test for root while (parent) { is correct for the real root, but incorrect for tasks in a policy namespace. This allows the task to walk backup the policy tree past its virtual root causing it to be unlocked before the virtual root should be in the p_stop fn. This results in the following lockdep back trace: [ 78.479744] [ BUG: bad unlock balance detected! ] [ 78.479792] 3.11.0-11-generic #17 Not tainted [ 78.479838] ------------------------------------- [ 78.479885] grep/2223 is trying to release lock (&ns->lock) at: [ 78.479952] [<ffffffff817bf3be>] mutex_unlock+0xe/0x10 [ 78.480002] but there are no more locks to release! [ 78.480037] [ 78.480037] other info that might help us debug this: [ 78.480037] 1 lock held by grep/2223: [ 78.480037] #0: (&p->lock){+.+.+.}, at: [<ffffffff812111bd>] seq_read+0x3d/0x3d0 [ 78.480037] [ 78.480037] stack backtrace: [ 78.480037] CPU: 0 PID: 2223 Comm: grep Not tainted 3.11.0-11-generic #17 [ 78.480037] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 78.480037] ffffffff817bf3be ffff880007763d60 ffffffff817b97ef ffff8800189d2190 [ 78.480037] ffff880007763d88 ffffffff810e1c6e ffff88001f044730 ffff8800189d2190 [ 78.480037] ffffffff817bf3be ffff880007763e00 ffffffff810e5bd6 0000000724fe56b7 [ 78.480037] Call Trace: [ 78.480037] [<ffffffff817bf3be>] ? mutex_unlock+0xe/0x10 [ 78.480037] [<ffffffff817b97ef>] dump_stack+0x54/0x74 [ 78.480037] [<ffffffff810e1c6e>] print_unlock_imbalance_bug+0xee/0x100 [ 78.480037] [<ffffffff817bf3be>] ? mutex_unlock+0xe/0x10 [ 78.480037] [<ffffffff810e5bd6>] lock_release_non_nested+0x226/0x300 [ 78.480037] [<ffffffff817bf2fe>] ? __mutex_unlock_slowpath+0xce/0x180 [ 78.480037] [<ffffffff817bf3be>] ? mutex_unlock+0xe/0x10 [ 78.480037] [<ffffffff810e5d5c>] lock_release+0xac/0x310 [ 78.480037] [<ffffffff817bf2b3>] __mutex_unlock_slowpath+0x83/0x180 [ 78.480037] [<ffffffff817bf3be>] mutex_unlock+0xe/0x10 [ 78.480037] [<ffffffff81376c91>] p_stop+0x51/0x90 [ 78.480037] [<ffffffff81211408>] seq_read+0x288/0x3d0 [ 78.480037] [<ffffffff811e9d9e>] vfs_read+0x9e/0x170 [ 78.480037] [<ffffffff811ea8cc>] SyS_read+0x4c/0xa0 [ 78.480037] [<ffffffff817ccc9d>] system_call_fastpath+0x1a/0x1f Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: James Morris <james.l.morris@oracle.com> |
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| .. | ||
| apparmor | ||
| integrity | ||
| keys | ||
| selinux | ||
| smack | ||
| tomoyo | ||
| yama | ||
| capability.c | ||
| commoncap.c | ||
| device_cgroup.c | ||
| inode.c | ||
| Kconfig | ||
| lsm_audit.c | ||
| Makefile | ||
| min_addr.c | ||
| security.c | ||