Hi,

Syzbot reported an easily reproducible NULL pointer dereference which I was
struggling to analyze:
https://syzkaller.appspot.com/bug?extid=7f23bcddf626e0593a39

Although direct fix is obvious, I could not actually find the exact race
condition scenario leading to it.  The patch fixes the issue - at least under
my QEMU - however all this code looks racy, so I have a feeling I am plumbing
one leak without fixing root cause.

Therefore I would appreciate some more thoughts on first commit.

Testing
=======
Under QEMU only. The NFC/LLCP code was not really tested on a device.

Best regards,
Krzysztof

Krzysztof Kozlowski (1):
  nfc: llcp: fix NULL error pointer dereference on sendmsg() after
    failed bind()

 net/nfc/llcp_sock.c | 5 +++++
 1 file changed, 5 insertions(+)

-- 
2.32.0

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <davem@davemloft.net>:

On Wed, 19 Jan 2022 08:48:15 +0100 you wrote:
> Hi,
> 
> Syzbot reported an easily reproducible NULL pointer dereference which I was
> struggling to analyze:
> https://syzkaller.appspot.com/bug?extid=7f23bcddf626e0593a39
> 
> Although direct fix is obvious, I could not actually find the exact race
> condition scenario leading to it.  The patch fixes the issue - at least under
> my QEMU - however all this code looks racy, so I have a feeling I am plumbing
> one leak without fixing root cause.
> 
> [...]

Here is the summary with links:
  - [v2,1/1] nfc: llcp: fix NULL error pointer dereference on sendmsg() after failed bind()
    https://git.kernel.org/netdev/net/c/dded08927ca3

You are awesome, thank you!
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