KASAN: slab-out-of-bounds Write in end_requests

KASAN: slab-out-of-bounds Write in end_requests

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    dd63bf22fccd Merge branch 'i2c/for-current' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10b9c770400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ffb4428fdc82f93b
dashboard link: https://syzkaller.appspot.com/bug?extid=cd4b9b3648c78dbd7fca
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=11b9732c400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16c469a4400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+cd4b9b3648c78dbd7fca@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-out-of-bounds in end_requests+0x37b/0x460  
fs/fuse/dev.c:2042
Write of size 4 at addr ffff8801c71b2fe4 by task syz-executor467/7211

CPU: 0 PID: 7211 Comm: syz-executor467 Not tainted 4.18.0-rc6+ #166
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
  ? dump_stack_print_info.cold.2


---
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Re: KASAN: slab-out-of-bounds Write in end_requests

[syzbot]

syzbot suspects this bug was fixed by commit:

commit 45ff350bbd9d0f0977ff270a0d427c71520c0c37
Author: Miklos Szeredi <mszeredi@redhat.com>
Date:   Thu Jul 26 14:13:11 2018 +0000

     fuse: fix unlocked access to processing queue

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1494e3ec600000
start commit:   dd63bf22 Merge branch 'i2c/for-current' of git://git.kerne..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=ffb4428fdc82f93b
dashboard link: https://syzkaller.appspot.com/bug?extid=cd4b9b3648c78dbd7fca
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11b9732c400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16c469a4400000

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

#syz fix: fuse: fix unlocked access to processing queue

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