Hello, syzbot found the following issue on: HEAD commit: d8be0e12 Add linux-next specific files for 20200824 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=12fa85ee900000 kernel config: https://syzkaller.appspot.com/x/.config?x=9ef0a5f95935d447 dashboard link: https://syzkaller.appspot.com/bug?extid=17675037466844188253 compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16f90519900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=153d3f5e900000 The issue was bisected to: commit 2da22da573481cc4837e246d0eee4d518b3f715e Author: Mike Christie <mchristi@xxxxxxxxxx> Date: Tue Aug 13 16:39:52 2019 +0000 nbd: fix zero cmd timeout handling v2 bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15af02de900000 final oops: https://syzkaller.appspot.com/x/report.txt?x=17af02de900000 console output: https://syzkaller.appspot.com/x/log.txt?x=13af02de900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+17675037466844188253@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 2da22da57348 ("nbd: fix zero cmd timeout handling v2") INFO: task syz-executor066:6866 can't die for more than 143 seconds. task:syz-executor066 state:D stack:28568 pid: 6866 ppid: 6855 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 io_schedule+0xb5/0x120 kernel/sched/core.c:6296 wait_on_page_bit_common+0x52c/0xca0 mm/filemap.c:1193 wait_on_page_bit mm/filemap.c:1218 [inline] wait_on_page_locked include/linux/pagemap.h:611 [inline] do_read_cache_page+0x257/0x1390 mm/filemap.c:2917 read_mapping_page include/linux/pagemap.h:437 [inline] read_part_sector+0xf6/0x5af block/partitions/core.c:770 adfspart_check_ICS+0x9d/0xc90 block/partitions/acorn.c:360 check_partition block/partitions/core.c:140 [inline] blk_add_partitions+0x445/0xe00 block/partitions/core.c:698 bdev_disk_changed+0x1ea/0x370 fs/block_dev.c:1416 __blkdev_get+0xee4/0x1aa0 fs/block_dev.c:1559 blkdev_get fs/block_dev.c:1639 [inline] blkdev_open+0x227/0x300 fs/block_dev.c:1753 do_dentry_open+0x4b9/0x11b0 fs/open.c:817 do_open fs/namei.c:3251 [inline] path_openat+0x1b9a/0x2730 fs/namei.c:3368 do_filp_open+0x17e/0x3c0 fs/namei.c:3395 do_sys_openat2+0x16d/0x420 fs/open.c:1168 do_sys_open fs/open.c:1184 [inline] __do_sys_open fs/open.c:1192 [inline] __se_sys_open fs/open.c:1188 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1188 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x405811 Code: Bad RIP value. RSP: 002b:00007f3442d94980 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000405811 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f3442d94990 RBP: 6666666666666667 R08: 000000000000000f R09: 00007f3442d95700 R10: 00007f3442d959d0 R11: 0000000000000293 R12: 00000000006dbc4c R13: 00007fffc941905f R14: 00007f3442d959c0 R15: 20c49ba5e353f7cf INFO: task syz-executor066:6866 blocked for more than 143 seconds. Not tainted 5.9.0-rc2-next-20200824-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor066 state:D stack:28568 pid: 6866 ppid: 6855 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 io_schedule+0xb5/0x120 kernel/sched/core.c:6296 wait_on_page_bit_common+0x52c/0xca0 mm/filemap.c:1193 wait_on_page_bit mm/filemap.c:1218 [inline] wait_on_page_locked include/linux/pagemap.h:611 [inline] do_read_cache_page+0x257/0x1390 mm/filemap.c:2917 read_mapping_page include/linux/pagemap.h:437 [inline] read_part_sector+0xf6/0x5af block/partitions/core.c:770 adfspart_check_ICS+0x9d/0xc90 block/partitions/acorn.c:360 check_partition block/partitions/core.c:140 [inline] blk_add_partitions+0x445/0xe00 block/partitions/core.c:698 bdev_disk_changed+0x1ea/0x370 fs/block_dev.c:1416 __blkdev_get+0xee4/0x1aa0 fs/block_dev.c:1559 blkdev_get fs/block_dev.c:1639 [inline] blkdev_open+0x227/0x300 fs/block_dev.c:1753 do_dentry_open+0x4b9/0x11b0 fs/open.c:817 do_open fs/namei.c:3251 [inline] path_openat+0x1b9a/0x2730 fs/namei.c:3368 do_filp_open+0x17e/0x3c0 fs/namei.c:3395 do_sys_openat2+0x16d/0x420 fs/open.c:1168 do_sys_open fs/open.c:1184 [inline] __do_sys_open fs/open.c:1192 [inline] __se_sys_open fs/open.c:1188 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1188 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x405811 Code: Bad RIP value. RSP: 002b:00007f3442d94980 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000405811 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f3442d94990 RBP: 6666666666666667 R08: 000000000000000f R09: 00007f3442d95700 R10: 00007f3442d959d0 R11: 0000000000000293 R12: 00000000006dbc4c R13: 00007fffc941905f R14: 00007f3442d959c0 R15: 20c49ba5e353f7cf INFO: task syz-executor066:6867 can't die for more than 143 seconds. task:syz-executor066 state:D stack:28744 pid: 6867 ppid: 6855 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4661 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103 __blkdev_get+0x4b8/0x1aa0 fs/block_dev.c:1492 blkdev_get fs/block_dev.c:1639 [inline] blkdev_open+0x227/0x300 fs/block_dev.c:1753 do_dentry_open+0x4b9/0x11b0 fs/open.c:817 do_open fs/namei.c:3251 [inline] path_openat+0x1b9a/0x2730 fs/namei.c:3368 do_filp_open+0x17e/0x3c0 fs/namei.c:3395 do_sys_openat2+0x16d/0x420 fs/open.c:1168 do_sys_open fs/open.c:1184 [inline] __do_sys_open fs/open.c:1192 [inline] __se_sys_open fs/open.c:1188 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1188 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x405811 Code: Bad RIP value. RSP: 002b:00007f3442d73980 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000405811 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f3442d73990 RBP: 6666666666666667 R08: 000000000000000f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00000000006dbc5c R13: 00007fffc941905f R14: 00007f3442d749c0 R15: 20c49ba5e353f7cf INFO: task syz-executor066:6867 blocked for more than 144 seconds. Not tainted 5.9.0-rc2-next-20200824-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor066 state:D stack:28744 pid: 6867 ppid: 6855 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4661 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103 __blkdev_get+0x4b8/0x1aa0 fs/block_dev.c:1492 blkdev_get fs/block_dev.c:1639 [inline] blkdev_open+0x227/0x300 fs/block_dev.c:1753 do_dentry_open+0x4b9/0x11b0 fs/open.c:817 do_open fs/namei.c:3251 [inline] path_openat+0x1b9a/0x2730 fs/namei.c:3368 do_filp_open+0x17e/0x3c0 fs/namei.c:3395 do_sys_openat2+0x16d/0x420 fs/open.c:1168 do_sys_open fs/open.c:1184 [inline] __do_sys_open fs/open.c:1192 [inline] __se_sys_open fs/open.c:1188 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1188 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x405811 Code: Bad RIP value. RSP: 002b:00007f3442d73980 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000405811 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f3442d73990 RBP: 6666666666666667 R08: 000000000000000f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00000000006dbc5c R13: 00007fffc941905f R14: 00007f3442d749c0 R15: 20c49ba5e353f7cf Showing all locks held in the system: 1 lock held by khungtaskd/1172: #0: ffffffff89c675c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5825 2 locks held by in:imklog/6558: #0: ffff8880a77981b0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 #1: ffffffff89c675c0 (rcu_read_lock){....}-{1:2}, at: rq_lock kernel/sched/sched.h:1292 [inline] #1: ffffffff89c675c0 (rcu_read_lock){....}-{1:2}, at: ttwu_queue kernel/sched/core.c:2698 [inline] #1: ffffffff89c675c0 (rcu_read_lock){....}-{1:2}, at: try_to_wake_up+0x52b/0x12b0 kernel/sched/core.c:2978 1 lock held by syz-executor066/6866: #0: ffff8880913452c0 (&bdev->bd_mutex){+.+.}-{3:3}, at: __blkdev_get+0x4b8/0x1aa0 fs/block_dev.c:1492 1 lock held by syz-executor066/6867: #0: ffff8880913452c0 (&bdev->bd_mutex){+.+.}-{3:3}, at: __blkdev_get+0x4b8/0x1aa0 fs/block_dev.c:1492 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1172 Comm: khungtaskd Not tainted 5.9.0-rc2-next-20200824-syzkaller #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+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd89/0xf30 kernel/hung_task.c:339 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3887 Comm: systemd-journal Not tainted 5.9.0-rc2-next-20200824-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__orc_find+0x6/0xf0 arch/x86/kernel/unwind_orc.c:34 Code: be e8 1e 0e 81 00 48 c7 c7 a0 d0 48 88 e8 d2 d6 81 02 cc cc 48 8b 07 c3 66 90 66 2e 0f 1f 84 00 00 00 00 00 41 57 89 d0 41 56 <41> 55 41 54 4c 8d 64 87 fc 55 53 48 83 ec 10 85 d2 0f 84 95 00 00 RSP: 0018:ffffc900054c79b8 EFLAGS: 00000006 RAX: 000000000000000c RBX: 1ffff92000a98f42 RCX: ffffffff87f5509c RDX: 000000000000000c RSI: ffffffff8ba52a20 RDI: ffffffff8b1d959c RBP: 0000000000000001 R08: ffffffff8ba52a68 R09: ffffffff8ba52a20 R10: 000000000007201e R11: 0000000000161242 R12: ffffc900054c7af0 R13: ffffc900054c7add R14: ffffc900054c7af8 R15: ffffc900054c7aa8 FS: 00007fa933e108c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa9311c1000 CR3: 00000000941f8000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: orc_find arch/x86/kernel/unwind_orc.c:172 [inline] unwind_next_frame+0x342/0x1f90 arch/x86/kernel/unwind_orc.c:449 arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3418 [inline] kmem_cache_free.part.0+0x67/0x1f0 mm/slab.c:3693 __put_cred+0x1de/0x250 kernel/cred.c:148 put_cred include/linux/cred.h:287 [inline] put_cred include/linux/cred.h:280 [inline] revert_creds+0x1a8/0x1f0 kernel/cred.c:598 do_faccessat+0x2ca/0x820 fs/open.c:464 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fa9330cc9c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffc39eb4fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffc39eb8010 RCX: 00007fa9330cc9c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000560f967b09a3 RBP: 00007ffc39eb5130 R08: 0000560f967a63e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000560f9771a8a0 R15: 00007ffc39eb5620 --- 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@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
