Re: [PATCH V2 linux-next] ipc/msg.c: fix memory leak in do_msgsnd()

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Aug 01, 2016 at 01:40:58PM +0200, 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@skynet.be>
> ---
> V2: Update description with original commit and cc stable
> (Suggested by Manfred Spraul)
> 
>  ipc/msg.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read Documentation/stable_kernel_rules.txt
for how to do this properly.

</formletter>