On Thu, 2021-09-23 at 13:20 -0400, Desmond Cheong Zhi Xi wrote:

On 23/9/21 2:03 am, syzbot wrote:

quoted

syzbot suspects this issue was fixed by commit:

commit f671a691e299f58835d4660d642582bf0e8f6fda
Author: Desmond Cheong Zhi Xi [off-list ref]
Date:   Fri Jul 2 09:18:30 2021 +0000

     fcntl: fix potential deadlocks for &fown_struct.lock

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=15fa8017300000
start commit:   293837b9ac8d Revert "i915: fix remap_io_sg to verify the p..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=18fade5827eb74f7
dashboard link: https://syzkaller.appspot.com/bug?extid=8073030e235a5a84dd31
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=171390add00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10050553d00000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: fcntl: fix potential deadlocks for &fown_struct.lock

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

#syz fix: fcntl: fix potential deadlocks for &fown_struct.lock

Think I got jumbled a bit when marking the dups. This bug shares the 
same root cause as [1], and is fixed by the same patch. Nice that Syzbot 
noticed.

Link: https://syzkaller.appspot.com/bug?extid=e6d5398a02c516ce5e70 [1]

Yeah, I had forgotten about that syzkaller report entirely.

I'm not sure we can do much about it now that the patch is already
merged though. Is there a process for amending changelogs for patches
already in Linus' tree?

If I had gotten this email while it was still sitting in linux-next, I
would have added that line. The syzkaller folks might want to consider
occasionally doing these sorts of checks vs. linux-next to catch this
sort of thing, if they care about the attribution.
-- 
Jeff Layton [off-list ref]