Messages in this thread | | | From | Kuniyuki Iwashima <> | Subject | Re: [syzbot] [net?] possible deadlock in unix_notinflight | Date | Wed, 10 Apr 2024 15:30:40 -0700 |
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From: syzbot <syzbot+38b3aa8cd529958bd27a@syzkaller.appspotmail.com> Date: Wed, 10 Apr 2024 11:45:29 -0700 > Hello, > > syzbot found the following issue on: > > HEAD commit: 443574b03387 riscv, bpf: Fix kfunc parameters incompatibil.. > git tree: bpf > console+strace: https://syzkaller.appspot.com/x/log.txt?x=12898aa9180000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440 > dashboard link: https://syzkaller.appspot.com/bug?extid=38b3aa8cd529958bd27a > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13d693e3180000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11aee305180000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/3f355021a085/disk-443574b0.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/44cf4de7472a/vmlinux-443574b0.xz > kernel image: https://storage.googleapis.com/syzbot-assets/a99a36c7ad65/bzImage-443574b0.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+38b3aa8cd529958bd27a@syzkaller.appspotmail.com > > ============================================ > WARNING: possible recursive locking detected > 6.8.0-syzkaller-05236-g443574b03387 #0 Not tainted > -------------------------------------------- > kworker/u8:0/10 is trying to acquire lock: > ffffffff8f48b798 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] > ffffffff8f48b798 (unix_gc_lock){+.+.}-{2:2}, at: unix_notinflight+0x204/0x390 net/unix/garbage.c:140 > > but task is already holding lock: > ffffffff8f48b798 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] > ffffffff8f48b798 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0x117/0xf10 net/unix/garbage.c:261 > > other info that might help us debug this: > Possible unsafe locking scenario: > > CPU0 > ---- > lock(unix_gc_lock); > lock(unix_gc_lock); > > *** DEADLOCK *** > > May be due to missing lock nesting notation > > 3 locks held by kworker/u8:0/10: > #0: ffff888014c81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] > #0: ffff888014c81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335 > #1: ffffc900000f7d00 (unix_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] > #1: ffffc900000f7d00 (unix_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335 > #2: ffffffff8f48b798 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] > #2: ffffffff8f48b798 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0x117/0xf10 net/unix/garbage.c:261 > > stack backtrace: > CPU: 1 PID: 10 Comm: kworker/u8:0 Not tainted 6.8.0-syzkaller-05236-g443574b03387 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 > Workqueue: events_unbound __unix_gc > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 > check_deadlock kernel/locking/lockdep.c:3062 [inline] > validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856 > __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 > lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 > __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] > _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 > spin_lock include/linux/spinlock.h:351 [inline] > unix_notinflight+0x204/0x390 net/unix/garbage.c:140 > unix_detach_fds net/unix/af_unix.c:1819 [inline] > unix_destruct_scm+0x221/0x350 net/unix/af_unix.c:1876 > skb_release_head_state+0x100/0x250 net/core/skbuff.c:1188 > skb_release_all net/core/skbuff.c:1200 [inline] > __kfree_skb net/core/skbuff.c:1216 [inline] > kfree_skb_reason+0x15d/0x390 net/core/skbuff.c:1252 > kfree_skb include/linux/skbuff.h:1267 [inline] > __unix_gc+0xaf3/0xf10 net/unix/garbage.c:330 > process_one_work kernel/workqueue.c:3254 [inline] > process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335 > worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 > kthread+0x2f0/0x390 kernel/kthread.c:388 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 > </TASK> > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > If the report is already addressed, let syzbot know by replying with: > #syz fix: exact-commit-title
#syz fix: af_unix: Clear stale u->oob_skb.
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