syzbot


WARNING: refcount bug in j1939_netdev_start

Status: fixed on 2019/11/29 15:48
Subsystems: can
[Documentation on labels]
Reported-by: syzbot+afd421337a736d6c1ee6@syzkaller.appspotmail.com
Fix commit: fd81ebfe7975 can: j1939: socket: rework socket locking for j1939_sk_release() and j1939_sk_sendmsg()
First crash: 1862d, last: 1841d
Cause bisection: introduced by (bisect log) :
commit 9d71dd0c70099914fcd063135da3c580865e924c
Author: The j1939 authors <linux-can@vger.kernel.org>
Date: Mon Oct 8 09:48:36 2018 +0000

  can: add support of SAE J1939 protocol

Crash: WARNING: refcount bug in j1939_netdev_start (log)
Repro: syz .config
  
Discussions (3)
Title Replies (including bot) Last reply
[PATCH v1 0/9] can: j1939: fix multiple issues found by syzbot 16 (16) 2019/11/13 10:04
[PATCH 4/9] can: j1939: socket: rework socket locking for j1939_sk_release() and j1939_sk_sendmsg() 1 (1) 2019/11/13 09:55
WARNING: refcount bug in j1939_netdev_start 0 (3) 2019/11/11 16:07
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING: refcount bug in j1939_netdev_start (2) can syz error error 51 1147d 1794d 20/28 fixed on 2022/03/08 16:11

Sample crash report:
------------[ cut here ]------------
refcount_t: increment on 0; use-after-free.
WARNING: CPU: 1 PID: 8514 at lib/refcount.c:156 refcount_inc_checked+0x4b/0x50 lib/refcount.c:156
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 8514 Comm: syz-executor.3 Not tainted 5.4.0-rc6+ #0
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+0x1fb/0x318 lib/dump_stack.c:118
 panic+0x264/0x7a9 kernel/panic.c:221
 __warn+0x20e/0x210 kernel/panic.c:582
 report_bug+0x1b6/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap+0xd7/0x440 arch/x86/kernel/traps.c:272
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:refcount_inc_checked+0x4b/0x50 lib/refcount.c:156
Code: 3d f7 ab 75 05 01 75 08 e8 12 e2 2d fe 5b 5d c3 e8 0a e2 2d fe c6 05 e1 ab 75 05 01 48 c7 c7 b4 c5 40 88 31 c0 e8 a5 78 00 fe <0f> 0b eb df 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 10
RSP: 0018:ffff8880816dfd10 EFLAGS: 00010246
RAX: 8358cd98639ffe00 RBX: ffff8880975b50f0 RCX: ffff8880a4010540
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffff8880816dfd18 R08: ffffffff815ca054 R09: ffffed1015d640d2
R10: ffffed1015d640d2 R11: 0000000000000000 R12: ffff88808e820588
R13: dffffc0000000000 R14: ffff88808e820000 R15: 1ffff11011d04047
 j1939_netdev_start+0x47c/0x730 net/can/j1939/main.c:267
 j1939_sk_bind+0x2c0/0xac0 net/can/j1939/socket.c:438
 __sys_bind+0x2c2/0x3a0 net/socket.c:1647
 __do_sys_bind net/socket.c:1658 [inline]
 __se_sys_bind net/socket.c:1656 [inline]
 __x64_sys_bind+0x7a/0x90 net/socket.c:1656
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a219
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007efc734cbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a219
RDX: 0000000000000018 RSI: 0000000020000240 RDI: 0000000000000005
RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007efc734cc6d4
R13: 00000000004c057e R14: 00000000004d2c50 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/11/11 12:04 upstream 9805a68371ce dc438b91 .config console log report syz ci-upstream-kasan-gce-smack-root
2019/11/10 13:38 upstream 00aff6836241 dc438b91 .config console log report ci-upstream-kasan-gce
2019/11/05 19:05 upstream a99d8080aaf3 0f3ec414 .config console log report ci-upstream-kasan-gce-root
2019/11/27 09:24 net-old a95069ecb709 1048481f .config console log report ci-upstream-net-this-kasan-gce
2019/11/05 18:52 net-old 3d1e5039f5f8 0f3ec414 .config console log report ci-upstream-net-this-kasan-gce
2019/11/27 08:37 net-next-old be2eca94d144 1048481f .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.