Re: [PATCH net v2] net: crypto set sk to NULL when af_alg_release.

[David Miller]

From: Mao Wenan <maowenan@xxxxxxxxxx>
Date: Mon, 18 Feb 2019 10:44:44 +0800

> KASAN has found use-after-free in sockfs_setattr.
> The existed commit 6d8c50dcb029 ("socket: close race condition between sock_close()
> and sockfs_setattr()") is to fix this simillar issue, but it seems to ignore
> that crypto module forgets to set the sk to NULL after af_alg_release.
> 
> KASAN report details as below:
> BUG: KASAN: use-after-free in sockfs_setattr+0x120/0x150
> Write of size 4 at addr ffff88837b956128 by task syz-executor0/4186
 ...
> Fixes: 6d8c50dcb029 ("socket: close race condition between sock_close() and sockfs_setattr()")
> Signed-off-by: Mao Wenan <maowenan@xxxxxxxxxx>

Applied and queued up for -stable, thanks.