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 <email address hidden>
Signed-off-by: Andy Whitcroft <email address hidden>
UBUNTU: SAUCE: apparmor: allocate path lookup buffers during init
BugLink: http://bugs.launchpad.net/bugs/1208988
dependency of: fix unix domain sockets to be mediated on connection needed to fix sleep in atomic context
Dynamically allocating buffers to store the path lookup slows mediation
down, and may require being able to sleep or accept failure of buffer
allocation. Handling fd inheritance during committing_creds, and unix
domain sockets can't fail nor can it sleep to do an allocation, so it
requires having preallocated buffers.
So add support for preallocated buffers and convert everything that
can be to use them.
Signed-off-by: John Johansen <email address hidden>
Signed-off-by: Andy Whitcroft <email address hidden>
