Re: [PATCH net] net: nfc: llcp: Add lock when modifying device list

On Mon, Sep 11, 2023 at 02:52:51PM +0200, Simon Horman wrote:

On Mon, Sep 11, 2023 at 07:59:04AM +0200, Simon Horman wrote:

quoted

On Sun, Sep 10, 2023 at 07:06:19PM -0400, Jeremy Cline wrote:

quoted

On Sun, Sep 10, 2023 at 05:28:12PM +0200, Simon Horman wrote:

quoted

On Fri, Sep 08, 2023 at 07:58:53PM -0400, Jeremy Cline wrote:

quoted

The device list needs its associated lock held when modifying it, or the
list could become corrupted, as syzbot discovered.

Reported-and-tested-by: syzbot+c1d0a03d305972dbbe14@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c1d0a03d305972dbbe14
Signed-off-by: Jeremy Cline <redacted>

Hi Jeremy,

thanks for your patch.

I don't think you need to resubmit for this,
I think this patch warrants a fixes tag:

Fixes: d646960f7986 ("NFC: Initial LLCP support")

My bad, indeed. The lock in question looks to have been added in
6709d4b7bc2e ("net: nfc: Fix use-after-free caused by
nfc_llcp_find_local") which itself includes a couple fix tags, should
this reference that commit instead as it won't backport without that
one?

Yes, I think that is likely.
Sorry for not noticing that.

And further, sorry for being vague in my previous email.
Having now looked over 6709d4b7bc2e I agree it is
the correct commit for a fixes tag for this patch.

Super, thanks. If it's helpful I can re-roll the patch, otherwise I'll
just leave it as-is.

Thanks,
Jeremy