syzbot


WARNING: refcount bug in l2cap_global_chan_by_psm

Status: upstream: reported C repro on 2020/08/05 06:17
Reported-by: syzbot+39ad9f042519082fcec9@syzkaller.appspotmail.com
First crash: 694d, last: 331d

Cause bisection: introduced by (bisect log) :
commit 3c1e300966d7edc380e405b3ab70b6e3c813a121
Author: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Date: Tue Oct 18 19:44:12 2016 +0000

  [media] si4713: don't break long lines

Crash: WARNING in nf_unregister_net_hook (log)
Repro: C syz .config

Fix bisection: the fix commit could be any of (bisect log):
  449dc8c97089 Merge tag 'for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply
  9e9fb7655ed5 Merge tag 'net-next-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Sample crash report:
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 6853 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 6853 Comm: kworker/u5:2 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci0 hci_rx_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:231
 __warn.cold+0x20/0x45 kernel/panic.c:600
 report_bug+0x1bd/0x210 lib/bug.c:198
 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234
 exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536
RIP: 0010:refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
Code: 07 31 ff 89 de e8 c7 ea da fd 84 db 0f 85 36 ff ff ff e8 7a ee da fd 48 c7 c7 a0 aa 93 88 c6 05 1c 6e 13 07 01 e8 19 fa ab fd <0f> 0b e9 17 ff ff ff e8 5b ee da fd 0f b6 1d 01 6e 13 07 31 ff 89
RSP: 0018:ffffc900055c7908 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88809769a480 RSI: ffffffff815db887 RDI: fffff52000ab8f13
RBP: 0000000000000002 R08: 0000000000000001 R09: ffff8880ae731927
R10: 0000000000000000 R11: 0000000035383654 R12: dffffc0000000000
R13: 0000000000000001 R14: ffff8880a6c18000 R15: 0000000000000003
 refcount_add include/linux/refcount.h:204 [inline]
 refcount_inc include/linux/refcount.h:241 [inline]
 kref_get include/linux/kref.h:45 [inline]
 l2cap_chan_hold net/bluetooth/l2cap_core.c:495 [inline]
 l2cap_global_chan_by_psm+0x53f/0x5b0 net/bluetooth/l2cap_core.c:1978
 l2cap_conless_channel net/bluetooth/l2cap_core.c:7595 [inline]
 l2cap_recv_frame+0xc3b/0xae10 net/bluetooth/l2cap_core.c:7665
 l2cap_recv_acldata+0x7f6/0x8e0 net/bluetooth/l2cap_core.c:8314
 hci_acldata_packet net/bluetooth/hci_core.c:4703 [inline]
 hci_rx_work+0x4c7/0xb50 net/bluetooth/hci_core.c:4894
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (26):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2020/08/08 18:51 upstream 449dc8c97089 f721e4a0 .config log report syz C
ci-upstream-kasan-gce-root 2020/08/07 19:15 upstream d6efb3ac3e6c cb436c69 .config log report syz C
ci-upstream-kasan-gce-root 2020/08/07 11:27 upstream d6efb3ac3e6c cb436c69 .config log report syz C
ci-upstream-kasan-gce-root 2020/08/07 10:43 upstream d6efb3ac3e6c cb436c69 .config log report syz C
ci-upstream-kasan-gce-root 2020/08/07 06:10 upstream 47ec5303d73e 1f122f88 .config log report syz C
ci-upstream-kasan-gce-selinux-root 2020/08/07 02:57 upstream 47ec5303d73e 1f122f88 .config log report syz C
ci-upstream-kasan-gce-root 2020/08/06 21:41 upstream 47ec5303d73e 1f122f88 .config log report syz C
ci-upstream-kasan-gce-smack-root 2020/08/06 20:20 upstream 47ec5303d73e 1f122f88 .config log report syz C
ci-upstream-kasan-gce-selinux-root 2020/08/06 18:32 upstream 47ec5303d73e 1f122f88 .config log report syz C
ci-upstream-kasan-gce-selinux-root 2020/08/06 07:08 upstream fffe3ae0ee84 0487ea6f .config log report syz C
ci-upstream-kasan-gce-selinux-root 2020/08/06 06:38 upstream fffe3ae0ee84 0487ea6f .config log report syz C
ci-upstream-kasan-gce-selinux-root 2020/08/06 05:17 upstream fffe3ae0ee84 0487ea6f .config log report syz C
ci-upstream-kasan-gce-selinux-root 2020/08/06 04:08 upstream fffe3ae0ee84 0487ea6f .config log report syz C
ci-upstream-kasan-gce-smack-root 2020/08/05 20:08 upstream 442489c21923 b7129355 .config log report syz C
ci-upstream-kasan-gce-selinux-root 2020/08/05 14:36 upstream 442489c21923 b7129355 .config log report syz C
ci-upstream-kasan-gce-smack-root 2020/08/05 13:11 upstream 442489c21923 b7129355 .config log report syz C
ci-upstream-kasan-gce-smack-root 2020/08/05 12:38 upstream 442489c21923 b7129355 .config log report syz C
ci-upstream-kasan-gce-smack-root 2020/08/05 12:09 upstream 442489c21923 b7129355 .config log report syz C
ci-upstream-kasan-gce-smack-root 2020/08/05 06:27 upstream c0842fbc1b18 80a06902 .config log report syz C
ci-upstream-kasan-gce-smack-root 2020/08/05 00:41 upstream c0842fbc1b18 80a06902 .config log report syz C
ci-upstream-linux-next-kasan-gce-root 2020/08/09 22:01 linux-next 01830e6c042e 70301872 .config log report syz C
ci-upstream-linux-next-kasan-gce-root 2020/08/09 21:28 linux-next 01830e6c042e 70301872 .config log report syz C
ci-upstream-linux-next-kasan-gce-root 2020/08/09 13:49 linux-next 01830e6c042e f721e4a0 .config log report syz C
ci-upstream-linux-next-kasan-gce-root 2020/08/09 12:02 linux-next 01830e6c042e f721e4a0 .config log report syz C
ci-upstream-linux-next-kasan-gce-root 2020/08/09 04:44 linux-next 01830e6c042e f721e4a0 .config log report syz C
ci-upstream-kasan-gce-root 2020/08/07 11:08 upstream d6efb3ac3e6c cb436c69 .config log report syz