On Mon, 01 Aug 2016, Fabian Frederick wrote:
Commit 53dad6d3a8e5
("ipc: fix race with LSMs") updated ipc_rcu_putref() to receive
rcu freeing function but used generic ipc_rcu_free() instead
of msg_rcu_free() which does security cleaning.
Running LTP msgsnd06 with kmemleak gives the following:
cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff88003c0a11f8 (size 8):
comm "msgsnd06", pid 1645, jiffies 4294672526 (age 6.549s)
hex dump (first 8 bytes):
1b 00 00 00 01 00 00 00 ........
backtrace:
[<ffffffff818e2c43>] kmemleak_alloc+0x23/0x40
[<ffffffff81177f31>] kmem_cache_alloc_trace+0xe1/0x180
[<ffffffff812d42af>] selinux_msg_queue_alloc_security+0x3f/0xd0
[<ffffffff812cc6be>] security_msg_queue_alloc+0x2e/0x40
[<ffffffff812b94ee>] newque+0x4e/0x150
[<ffffffff812b8cb9>] ipcget+0x159/0x1b0
[<ffffffff812b98d9>] SyS_msgget+0x39/0x40
[<ffffffff818e7bdb>] entry_SYSCALL_64_fastpath+0x13/0x8f
[<ffffffffffffffff>] 0xffffffffffffffff
Signed-off-by: Fabian Frederick <fabf@xxxxxxxxx>
---
V2: Update description with original commit and cc stable
(Suggested by Manfred Spraul)
Ideally we would have the fix for sem.c in the same patch, under, ie:
"sysv, ipc: fix security-layer leaking"
Just like with shm and msg, the only caller of ipc_rcu_free() should be a
failed security allocation in newary().
Thanks,
Davidlohr
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