On Fri, Oct 27, 2017 at 10:09 AM, syzbot <bot+7feb8de6b4d6bf810cf098bef942cc387e79d0ad@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzkaller hit the following crash on > 2bd6bf03f4c1c59381d62c61d03f6cc3fe71f66e > git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > C reproducer is attached > syzkaller reproducer is attached. See https://goo.gl/kgGztJ > for information about syzkaller reproducers > > > ============================================ > WARNING: possible recursive locking detected > 4.14.0-rc1+ #88 Not tainted > -------------------------------------------- > syzkaller883997/2981 is trying to acquire lock: > (&grp->list_mutex){++++}, at: [<ffffffff83d4dd49>] deliver_to_subscribers > sound/core/seq/seq_clientmgr.c:666 [inline] > (&grp->list_mutex){++++}, at: [<ffffffff83d4dd49>] > snd_seq_deliver_event+0x279/0x790 sound/core/seq/seq_clientmgr.c:807 > > but task is already holding lock: > (&grp->list_mutex){++++}, at: [<ffffffff83d4dd49>] deliver_to_subscribers > sound/core/seq/seq_clientmgr.c:666 [inline] > (&grp->list_mutex){++++}, at: [<ffffffff83d4dd49>] > snd_seq_deliver_event+0x279/0x790 sound/core/seq/seq_clientmgr.c:807 > > other info that might help us debug this: > Possible unsafe locking scenario: > > CPU0 > ---- > lock(&grp->list_mutex); > lock(&grp->list_mutex); > > *** DEADLOCK *** > > May be due to missing lock nesting notation > > 2 locks held by syzkaller883997/2981: > #0: (register_mutex#4){+.+.}, at: [<ffffffff83d60ada>] > odev_release+0x4a/0x70 sound/core/seq/oss/seq_oss.c:152 > #1: (&grp->list_mutex){++++}, at: [<ffffffff83d4dd49>] > deliver_to_subscribers sound/core/seq/seq_clientmgr.c:666 [inline] > #1: (&grp->list_mutex){++++}, at: [<ffffffff83d4dd49>] > snd_seq_deliver_event+0x279/0x790 sound/core/seq/seq_clientmgr.c:807 > > stack backtrace: > CPU: 1 PID: 2981 Comm: syzkaller883997 Not tainted 4.14.0-rc1+ #88 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:16 [inline] > dump_stack+0x194/0x257 lib/dump_stack.c:52 > print_deadlock_bug kernel/locking/lockdep.c:1797 [inline] > check_deadlock kernel/locking/lockdep.c:1844 [inline] > validate_chain kernel/locking/lockdep.c:2453 [inline] > __lock_acquire+0x1232/0x4620 kernel/locking/lockdep.c:3498 > lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 > down_read+0x96/0x150 kernel/locking/rwsem.c:23 > deliver_to_subscribers sound/core/seq/seq_clientmgr.c:666 [inline] > snd_seq_deliver_event+0x279/0x790 sound/core/seq/seq_clientmgr.c:807 > snd_seq_kernel_client_dispatch+0x11e/0x150 > sound/core/seq/seq_clientmgr.c:2309 > dummy_input+0x2c4/0x400 sound/core/seq/seq_dummy.c:104 > snd_seq_deliver_single_event.constprop.11+0x2fb/0x940 > sound/core/seq/seq_clientmgr.c:621 > deliver_to_subscribers sound/core/seq/seq_clientmgr.c:676 [inline] > snd_seq_deliver_event+0x318/0x790 sound/core/seq/seq_clientmgr.c:807 > snd_seq_kernel_client_dispatch+0x11e/0x150 > sound/core/seq/seq_clientmgr.c:2309 > dummy_input+0x2c4/0x400 sound/core/seq/seq_dummy.c:104 > snd_seq_deliver_single_event.constprop.11+0x2fb/0x940 > sound/core/seq/seq_clientmgr.c:621 > snd_seq_deliver_event+0x12c/0x790 sound/core/seq/seq_clientmgr.c:818 > snd_seq_kernel_client_dispatch+0x11e/0x150 > sound/core/seq/seq_clientmgr.c:2309 > snd_seq_oss_dispatch sound/core/seq/oss/seq_oss_device.h:150 [inline] > snd_seq_oss_midi_reset+0x44b/0x700 sound/core/seq/oss/seq_oss_midi.c:481 > snd_seq_oss_synth_reset+0x398/0x980 sound/core/seq/oss/seq_oss_synth.c:416 > snd_seq_oss_reset+0x6c/0x260 sound/core/seq/oss/seq_oss_init.c:448 > snd_seq_oss_release+0x71/0x120 sound/core/seq/oss/seq_oss_init.c:425 > odev_release+0x52/0x70 sound/core/seq/oss/seq_oss.c:153 > __fput+0x333/0x7f0 fs/file_table.c:210 > ____fput+0x15/0x20 fs/file_table.c:244 > task_work_run+0x199/0x270 kernel/task_work.c:112 > exit_task_work include/linux/task_work.h:21 [inline] > do_exit+0xa52/0x1b40 kernel/exit.c:865 > do_group_exit+0x149/0x400 kernel/exit.c:968 > SYSC_exit_group kernel/exit.c:979 [inline] > SyS_exit_group+0x1d/0x20 kernel/exit.c:977 > entry_SYSCALL_64_fastpath+0x1f/0xbe > RIP: 0033:0x442c58 > RSP: 002b:00007ffd15d4f8d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442c58 > RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 > RBP: 0000000000000082 R08: 00000000000000e7 R09: ffffffffffffffd0 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401ca0 > R13: 0000000000401d30 R14 I've just re-reproduced this on upstream 15f859ae5c43c7f0a064ed92d33f7a5bc5de6de0 (Oct 26): ============================================ WARNING: possible recursive locking detected 4.14.0-rc6+ #10 Not tainted -------------------------------------------- a.out/3062 is trying to acquire lock: (&grp->list_mutex){++++}, at: [<ffffffff83d28879>] deliver_to_subscribers sound/core/seq/seq_clientmgr.c:666 [inline] (&grp->list_mutex){++++}, at: [<ffffffff83d28879>] snd_seq_deliver_event+0x279/0x790 sound/core/seq/seq_clientmgr.c:807 but task is already holding lock: (&grp->list_mutex){++++}, at: [<ffffffff83d28879>] deliver_to_subscribers sound/core/seq/seq_clientmgr.c:666 [inline] (&grp->list_mutex){++++}, at: [<ffffffff83d28879>] snd_seq_deliver_event+0x279/0x790 sound/core/seq/seq_clientmgr.c:807 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&grp->list_mutex); lock(&grp->list_mutex); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by a.out/3062: #0: (register_mutex#4){+.+.}, at: [<ffffffff83d3b5da>] odev_release+0x4a/0x70 sound/core/seq/oss/seq_oss.c:152 #1: (&grp->list_mutex){++++}, at: [<ffffffff83d28879>] deliver_to_subscribers sound/core/seq/seq_clientmgr.c:666 [inline] #1: (&grp->list_mutex){++++}, at: [<ffffffff83d28879>] snd_seq_deliver_event+0x279/0x790 sound/core/seq/seq_clientmgr.c:807 stack backtrace: CPU: 0 PID: 3062 Comm: a.out Not tainted 4.14.0-rc6+ #10 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_deadlock_bug kernel/locking/lockdep.c:1797 [inline] check_deadlock kernel/locking/lockdep.c:1844 [inline] validate_chain kernel/locking/lockdep.c:2445 [inline] __lock_acquire+0xed5/0x3d50 kernel/locking/lockdep.c:3490 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3994 down_read+0x96/0x150 kernel/locking/rwsem.c:23 deliver_to_subscribers sound/core/seq/seq_clientmgr.c:666 [inline] snd_seq_deliver_event+0x279/0x790 sound/core/seq/seq_clientmgr.c:807 snd_seq_kernel_client_dispatch+0x11e/0x150 sound/core/seq/seq_clientmgr.c:2313 dummy_input+0x2c4/0x400 sound/core/seq/seq_dummy.c:104 snd_seq_deliver_single_event.constprop.11+0x2fb/0x940 sound/core/seq/seq_clientmgr.c:621 deliver_to_subscribers sound/core/seq/seq_clientmgr.c:676 [inline] snd_seq_deliver_event+0x318/0x790 sound/core/seq/seq_clientmgr.c:807 snd_seq_kernel_client_dispatch+0x11e/0x150 sound/core/seq/seq_clientmgr.c:2313 dummy_input+0x2c4/0x400 sound/core/seq/seq_dummy.c:104 snd_seq_deliver_single_event.constprop.11+0x2fb/0x940 sound/core/seq/seq_clientmgr.c:621 snd_seq_deliver_event+0x12c/0x790 sound/core/seq/seq_clientmgr.c:818 snd_seq_kernel_client_dispatch+0x11e/0x150 sound/core/seq/seq_clientmgr.c:2313 snd_seq_oss_dispatch sound/core/seq/oss/seq_oss_device.h:150 [inline] snd_seq_oss_midi_reset+0x44b/0x700 sound/core/seq/oss/seq_oss_midi.c:481 snd_seq_oss_synth_reset+0x398/0x980 sound/core/seq/oss/seq_oss_synth.c:416 snd_seq_oss_reset+0x6c/0x260 sound/core/seq/oss/seq_oss_init.c:448 snd_seq_oss_release+0x71/0x120 sound/core/seq/oss/seq_oss_init.c:425 odev_release+0x52/0x70 sound/core/seq/oss/seq_oss.c:153 __fput+0x327/0x7e0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:112 exit_task_work include/linux/task_work.h:21 [inline] do_exit+0x9b5/0x1ad0 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:968 SYSC_exit_group kernel/exit.c:979 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:977 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x437b99 RSP: 002b:00007ffe1b782328 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000437b99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000082 R08: 000000000000003c R09: 00000000000000e7 R10: ffffffffffffffc0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000401c00 R14: 0000000000401c90 R15: 0000000000000000 > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. > Once a fix for this bug is committed, please reply to this email with: > #syz fix: exact-commit-title > To mark this as a duplicate of another syzbot report, please reply with: > #syz dup: exact-subject-of-another-report > If it's a one-off invalid bug report, please reply with: > #syz invalid > Note: if the crash happens again, it will cause creation of a new bug > report. > > -- > You received this message because you are subscribed to the Google Groups > "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit > https://groups.google.com/d/msgid/syzkaller-bugs/001a114089d614a0f4055c82d022%40google.com. > For more options, visit https://groups.google.com/d/optout. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
