On Tue, 12 Mar 2024 22:02:27 +0100 Jiri Olsa <olsajiri@xxxxxxxxx> > On Tue, Mar 12, 2024 at 09:41:26AM -0700, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: df4793505abd Merge tag 'net-6.8-rc8' of git://git.kernel.o.. > > git tree: bpf > > console+strace: https://syzkaller.appspot.com/x/log.txt?x=11fd0092180000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=c11c5c676adb61f0 > > dashboard link: https://syzkaller.appspot.com/bug?extid=850aaf14624dc0c6d366 > > 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=1509c4ae180000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10babc01180000 > > > > Downloadable assets: > > disk image: https://storage.googleapis.com/syzbot-assets/d2e80ee1112b/disk-df479350.raw.xz > > vmlinux: https://storage.googleapis.com/syzbot-assets/b35ea54cd190/vmlinux-df479350.xz > > kernel image: https://storage.googleapis.com/syzbot-assets/59f69d999ad2/bzImage-df479350.xz > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+850aaf14624dc0c6d366@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > ============================================ > > WARNING: possible recursive locking detected > > 6.8.0-rc7-syzkaller-gdf4793505abd #0 Not tainted > > -------------------------------------------- > > strace-static-x/5063 is trying to acquire lock: > > ffffc900096f10d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x211/0x4f0 kernel/bpf/ringbuf.c:424 > > > > but task is already holding lock: > > ffffc900098410d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x211/0x4f0 kernel/bpf/ringbuf.c:424 > > > > other info that might help us debug this: > > Possible unsafe locking scenario: > > > > CPU0 > > ---- > > lock(&rb->spinlock); > > lock(&rb->spinlock); > > > > *** DEADLOCK *** > > > > May be due to missing lock nesting notation > > > > 4 locks held by strace-static-x/5063: > > #0: ffff88807857e068 (&pipe->mutex/1){+.+.}-{3:3}, at: __pipe_lock fs/pipe.c:103 [inline] > > #0: ffff88807857e068 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_write+0x1cc/0x1a40 fs/pipe.c:465 > > #1: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] > > #1: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] > > #1: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] > > #1: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420 > > #2: ffffc900098410d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x211/0x4f0 kernel/bpf/ringbuf.c:424 > > #3: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] > > #3: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] > > #3: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] > > #3: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420 > > > > stack backtrace: > > CPU: 0 PID: 5063 Comm: strace-static-x Not tainted 6.8.0-rc7-syzkaller-gdf4793505abd #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 > > 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+0x15c0/0x58e0 kernel/locking/lockdep.c:3856 > > __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 > > lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 > > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > > _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 > > __bpf_ringbuf_reserve+0x211/0x4f0 kernel/bpf/ringbuf.c:424 > > ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:459 [inline] > > bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:451 > > bpf_prog_9efe54833449f08e+0x2d/0x47 > > bpf_dispatcher_nop_func include/linux/bpf.h:1231 [inline] > > __bpf_prog_run include/linux/filter.h:651 [inline] > > bpf_prog_run include/linux/filter.h:658 [inline] > > __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] > > hum, scratching my head how this could passed through the prog->active check, > will try to reproduce Feel free to take a look at another syzbot report [1,2] [1] Subject: Re: [syzbot] [ntfs3?] possible deadlock in ntfs_set_state (2) https://lore.kernel.org/lkml/ZdwSXCaTrzq7mm7Z@boqun-archlinux/ [2] Subject: Re: [syzbot] [bpf?] possible deadlock in __bpf_ringbuf_reserve https://lore.kernel.org/lkml/00000000000082883f061388d49e@xxxxxxxxxx/
