syzbot


WARNING: refcount bug in ppp_release

Status: auto-closed as invalid on 2022/02/07 09:09
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 389d, last: 389d

Sample crash report:
------------[ cut here ]------------
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 0 PID: 27702 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Modules linked in:
CPU: 0 PID: 27702 Comm: syz-executor.1 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Code: 1d 29 14 82 09 31 ff 89 de e8 ad ae 9e fd 84 db 75 e0 e8 64 a8 9e fd 48 c7 c7 20 2a e4 89 c6 05 09 14 82 09 01 e8 c1 55 1b 05 <0f> 0b eb c4 e8 48 a8 9e fd 0f b6 1d f8 13 82 09 31 ff 89 de e8 78
RSP: 0018:ffffc90002d37c80 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888017d20000 RSI: ffffffff815ef908 RDI: fffff520005a6f82
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815e96ee R11: 0000000000000000 R12: 0000000000000001
R13: ffffc90002d37dc8 R14: ffff888077ff25b0 R15: ffff888050efd980
FS:  0000555556d73400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200002c0 CR3: 000000007d5df000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __refcount_dec include/linux/refcount.h:344 [inline]
 refcount_dec include/linux/refcount.h:359 [inline]
 dev_put include/linux/netdevice.h:4166 [inline]
 unregister_netdevice_many+0x12c9/0x1790 net/core/dev.c:11111
 unregister_netdevice_queue+0x2dd/0x3c0 net/core/dev.c:11008
 unregister_netdevice include/linux/netdevice.h:2989 [inline]
 ppp_release+0x216/0x240 drivers/net/ppp/ppp_generic.c:404
 __fput+0x286/0x9f0 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f3f6bc7272b
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44
RSP: 002b:00007ffe3911a280 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00007f3f6bc7272b
RDX: 00007f3f6bddbbd8 RSI: ffffffff89377e11 RDI: 0000000000000005
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b31528b14
R10: 0000000000000fa0 R11: 0000000000000293 R12: 000000000007698c
R13: 00000000000003e8 R14: 00007f3f6bdd2f60 R15: 0000000000076929
 </TASK>

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-net-this-kasan-gce 2021/11/09 09:03 net c45231a7668d 8ab17e57 .config log report info WARNING: refcount bug in ppp_release
* Struck through repros no longer work on HEAD.