Re: [PATCH 1/1 linux-next] ipc/msg.c: fix memory leak in do_msgsnd()

[Manfred Spraul]

Hi Fabian,

On 07/29/2016 10:15 AM, Fabian Frederick wrote:
> 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
>
> ipc_rcu_free() was given to ipc_rcu_putref() instead of msg_rcu_free()
> which does security cleaning.
Good catch!

From a quick look:
- The same bug appears to exist in sem.c. Do you want to fix it as well?
- Did you check when it was introduced? I would add cc stable.

--
    Manfred