* [syzbot] INFO: task hung in ext4_fill_super @ 2021-06-16 9:56 syzbot 2021-06-16 16:22 ` Pavel Skripkin 2021-08-05 14:26 ` Pavel Skripkin 0 siblings, 2 replies; 7+ messages in thread From: syzbot @ 2021-06-16 9:56 UTC (permalink / raw) To: adilger.kernel, clang-built-linux, linux-ext4, linux-kernel, nathan, ndesaulniers, syzkaller-bugs, tytso Hello, syzbot found the following issue on: HEAD commit: f21b807c Merge tag 'drm-fixes-2021-06-11' of git://anongit.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=165fca57d00000 kernel config: https://syzkaller.appspot.com/x/.config?x=30f476588412c065 dashboard link: https://syzkaller.appspot.com/bug?extid=c9ff4822a62eee994ea3 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17d19ce0300000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=108d7988300000 Bisection is inconclusive: the issue happens on the oldest tested release. bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1646b8d0300000 final oops: https://syzkaller.appspot.com/x/report.txt?x=1546b8d0300000 console output: https://syzkaller.appspot.com/x/log.txt?x=1146b8d0300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+c9ff4822a62eee994ea3@syzkaller.appspotmail.com INFO: task syz-executor768:8567 blocked for more than 143 seconds. Not tainted 5.13.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor768 state:D stack:27544 pid: 8567 ppid: 8423 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x916/0x23e0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x168/0x270 kernel/sched/completion.c:138 kthread_stop+0x17a/0x720 kernel/kthread.c:642 ext4_fill_super+0x87ac/0xdfa0 fs/ext4/super.c:5190 mount_bdev+0x34d/0x410 fs/super.c:1368 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1498 do_new_mount fs/namespace.c:2905 [inline] path_mount+0x132a/0x1fa0 fs/namespace.c:3235 do_mount fs/namespace.c:3248 [inline] __do_sys_mount fs/namespace.c:3456 [inline] __se_sys_mount fs/namespace.c:3433 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3433 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x445b2a RSP: 002b:00007ffc5efbf598 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ffc5efbf5f0 RCX: 0000000000445b2a RDX: 0000000020000000 RSI: 00000000200000c0 RDI: 00007ffc5efbf5b0 RBP: 00007ffc5efbf5b0 R08: 00007ffc5efbf5f0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00000000200003f8 R13: 0000000000000003 R14: 0000000000000004 R15: 0000000000000005 Showing all locks held in the system: 1 lock held by khungtaskd/1636: #0: ffffffff8bf79620 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6333 2 locks held by in:imklog/8117: #0: ffff888015be9770 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:974 #1: ffff888021bc3958 (&mm->mmap_lock#2){++++}-{3:3}, at: file_ctx security/apparmor/include/file.h:33 [inline] #1: ffff888021bc3958 (&mm->mmap_lock#2){++++}-{3:3}, at: aa_file_perm+0x119/0x1170 security/apparmor/file.c:609 1 lock held by syz-executor768/8567: #0: ffff88802ac340e0 (&type->s_umount_key#27/1){+.+.}-{3:3}, at: alloc_super+0x1dd/0xab0 fs/super.c:229 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1636 Comm: khungtaskd Not tainted 5.13.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd48/0xfb0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:108 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x1c9/0x250 drivers/acpi/processor_idle.c:513 --- 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. 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 ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] INFO: task hung in ext4_fill_super 2021-06-16 9:56 [syzbot] INFO: task hung in ext4_fill_super syzbot @ 2021-06-16 16:22 ` Pavel Skripkin 2021-06-16 18:28 ` syzbot 2021-08-05 14:26 ` Pavel Skripkin 1 sibling, 1 reply; 7+ messages in thread From: Pavel Skripkin @ 2021-06-16 16:22 UTC (permalink / raw) To: syzbot Cc: adilger.kernel, clang-built-linux, linux-ext4, linux-kernel, nathan, ndesaulniers, syzkaller-bugs, tytso On Wed, 16 Jun 2021 02:56:21 -0700 syzbot <syzbot+c9ff4822a62eee994ea3@syzkaller.appspotmail.com> wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: f21b807c Merge tag 'drm-fixes-2021-06-11' of > git://anongit.. git tree: upstream > console output: > https://syzkaller.appspot.com/x/log.txt?x=165fca57d00000 kernel > config: https://syzkaller.appspot.com/x/.config?x=30f476588412c065 > dashboard link: > https://syzkaller.appspot.com/bug?extid=c9ff4822a62eee994ea3 syz > repro: > https://syzkaller.appspot.com/x/repro.syz?x=17d19ce0300000 C > reproducer: https://syzkaller.appspot.com/x/repro.c?x=108d7988300000 > > Bisection is inconclusive: the issue happens on the oldest tested > release. > > bisection log: > https://syzkaller.appspot.com/x/bisect.txt?x=1646b8d0300000 final > oops: https://syzkaller.appspot.com/x/report.txt?x=1546b8d0300000 > console output: > https://syzkaller.appspot.com/x/log.txt?x=1146b8d0300000 > > IMPORTANT: if you fix the issue, please add the following tag to the > commit: Reported-by: > syzbot+c9ff4822a62eee994ea3@syzkaller.appspotmail.com > Just want to try this ;) #syz test https://linux.googlesource.com/linux/kernel/git/torvalds/linux refs/changes/76/10176/6 With regards, Pavel Skripkin ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] INFO: task hung in ext4_fill_super 2021-06-16 16:22 ` Pavel Skripkin @ 2021-06-16 18:28 ` syzbot 0 siblings, 0 replies; 7+ messages in thread From: syzbot @ 2021-06-16 18:28 UTC (permalink / raw) To: adilger.kernel, clang-built-linux, linux-ext4, linux-kernel, nathan, ndesaulniers, paskripkin, syzkaller-bugs, tytso Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: INFO: task hung in ext4_stop_mmpd INFO: task syz-executor.3:10377 blocked for more than 143 seconds. Not tainted 5.12.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:27568 pid:10377 ppid: 8772 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x911/0x21b0 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x168/0x270 kernel/sched/completion.c:138 kthread_stop+0x17a/0x720 kernel/kthread.c:621 ext4_stop_mmpd+0x47/0xd0 fs/ext4/mmp.c:255 ext4_fill_super+0x86b5/0xdef0 fs/ext4/super.c:5159 mount_bdev+0x34d/0x410 fs/super.c:1367 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1497 do_new_mount fs/namespace.c:2903 [inline] path_mount+0x132a/0x1f90 fs/namespace.c:3233 do_mount fs/namespace.c:3246 [inline] __do_sys_mount fs/namespace.c:3454 [inline] __se_sys_mount fs/namespace.c:3431 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3431 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x467afa RSP: 002b:00007f311de49fa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000380 RCX: 0000000000467afa RDX: 0000000020000000 RSI: 00000000200000c0 RDI: 00007f311de4a000 RBP: 00007f311de4a040 R08: 00007f311de4a040 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000 R13: 00000000200000c0 R14: 00007f311de4a000 R15: 0000000020000200 INFO: task syz-executor.5:10410 blocked for more than 143 seconds. Not tainted 5.12.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack:27568 pid:10410 ppid: 8771 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x911/0x21b0 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x168/0x270 kernel/sched/completion.c:138 kthread_stop+0x17a/0x720 kernel/kthread.c:621 ext4_stop_mmpd+0x47/0xd0 fs/ext4/mmp.c:255 ext4_fill_super+0x86b5/0xdef0 fs/ext4/super.c:5159 mount_bdev+0x34d/0x410 fs/super.c:1367 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1497 do_new_mount fs/namespace.c:2903 [inline] path_mount+0x132a/0x1f90 fs/namespace.c:3233 do_mount fs/namespace.c:3246 [inline] __do_sys_mount fs/namespace.c:3454 [inline] __se_sys_mount fs/namespace.c:3431 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3431 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x467afa RSP: 002b:00007fe6fceb8fa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000380 RCX: 0000000000467afa RDX: 0000000020000000 RSI: 00000000200000c0 RDI: 00007fe6fceb9000 RBP: 00007fe6fceb9040 R08: 00007fe6fceb9040 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000 R13: 00000000200000c0 R14: 00007fe6fceb9000 R15: 0000000020000200 INFO: task syz-executor.2:10429 blocked for more than 143 seconds. Not tainted 5.12.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:27568 pid:10429 ppid: 8769 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x911/0x21b0 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x168/0x270 kernel/sched/completion.c:138 kthread_stop+0x17a/0x720 kernel/kthread.c:621 ext4_stop_mmpd+0x47/0xd0 fs/ext4/mmp.c:255 ext4_fill_super+0x86b5/0xdef0 fs/ext4/super.c:5159 mount_bdev+0x34d/0x410 fs/super.c:1367 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1497 do_new_mount fs/namespace.c:2903 [inline] path_mount+0x132a/0x1f90 fs/namespace.c:3233 do_mount fs/namespace.c:3246 [inline] __do_sys_mount fs/namespace.c:3454 [inline] __se_sys_mount fs/namespace.c:3431 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3431 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x467afa RSP: 002b:00007f92454eafa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000380 RCX: 0000000000467afa RDX: 0000000020000000 RSI: 00000000200000c0 RDI: 00007f92454eb000 RBP: 00007f92454eb040 R08: 00007f92454eb040 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000 R13: 00000000200000c0 R14: 00007f92454eb000 R15: 0000000020000200 INFO: task syz-executor.4:10440 blocked for more than 144 seconds. Not tainted 5.12.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:27464 pid:10440 ppid: 8774 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x911/0x21b0 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x168/0x270 kernel/sched/completion.c:138 kthread_stop+0x17a/0x720 kernel/kthread.c:621 ext4_stop_mmpd+0x47/0xd0 fs/ext4/mmp.c:255 ext4_fill_super+0x86b5/0xdef0 fs/ext4/super.c:5159 mount_bdev+0x34d/0x410 fs/super.c:1367 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1497 do_new_mount fs/namespace.c:2903 [inline] path_mount+0x132a/0x1f90 fs/namespace.c:3233 do_mount fs/namespace.c:3246 [inline] __do_sys_mount fs/namespace.c:3454 [inline] __se_sys_mount fs/namespace.c:3431 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3431 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x467afa RSP: 002b:00007f2fce3c2fa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000380 RCX: 0000000000467afa RDX: 0000000020000000 RSI: 00000000200000c0 RDI: 00007f2fce3c3000 RBP: 00007f2fce3c3040 R08: 00007f2fce3c3040 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000 R13: 00000000200000c0 R14: 00007f2fce3c3000 R15: 0000000020000200 Showing all locks held in the system: 2 locks held by kworker/u4:4/217: #0: ffff8880b9f35198 (&rq->lock){-.-.}-{2:2}, at: newidle_balance+0x789/0xe50 kernel/sched/fair.c:10633 #1: ffffffff8b774320 (rcu_read_lock){....}-{1:2}, at: cpu_of kernel/sched/sched.h:1086 [inline] #1: ffffffff8b774320 (rcu_read_lock){....}-{1:2}, at: __update_idle_core+0x39/0x430 kernel/sched/fair.c:6045 1 lock held by khungtaskd/1574: #0: ffffffff8b774320 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6327 1 lock held by in:imklog/8073: #0: ffff8880111a74f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:974 1 lock held by syz-executor.3/10377: #0: ffff8880441a20e0 (&type->s_umount_key#27/1){+.+.}-{3:3}, at: alloc_super+0x1dd/0xab0 fs/super.c:229 1 lock held by syz-executor.5/10410: #0: ffff88802ad4e0e0 (&type->s_umount_key#27/1){+.+.}-{3:3}, at: alloc_super+0x1dd/0xab0 fs/super.c:229 1 lock held by syz-executor.2/10429: #0: ffff8880446860e0 (&type->s_umount_key#27/1){+.+.}-{3:3}, at: alloc_super+0x1dd/0xab0 fs/super.c:229 1 lock held by syz-executor.4/10440: #0: ffff8880446920e0 (&type->s_umount_key#27/1){+.+.}-{3:3}, at: alloc_super+0x1dd/0xab0 fs/super.c:229 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1574 Comm: khungtaskd Not tainted 5.12.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd48/0xfb0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 217 Comm: kworker/u4:4 Not tainted 5.12.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5253 [inline] RIP: 0010:lock_is_held_type+0xa7/0x140 kernel/locking/lockdep.c:5549 Code: 12 e9 88 00 00 00 83 c3 01 41 3b 9c 24 e8 09 00 00 7d 7b 48 63 c3 48 89 ee 48 8d 04 80 4d 8d 7c c5 00 4c 89 ff e8 09 fe ff ff <85> c0 74 d8 41 83 fe ff 41 bd 01 00 00 00 74 12 41 0f b6 47 22 45 RSP: 0018:ffffc900018afaf8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8b774260 RDI: ffff888013df0a18 RBP: ffffffff8b774260 R08: 0000000000000000 R09: ffffffff8d45978f R10: fffffbfff1a8b2f1 R11: 0000000000000000 R12: ffff888013df0000 R13: ffff888013df09f0 R14: 00000000ffffffff R15: ffff888013df0a18 FS: 0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f205c60e020 CR3: 00000000158c4000 CR4: 0000000000350ee0 Call Trace: lock_is_held include/linux/lockdep.h:278 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x5d3/0x720 kernel/locking/lockdep.c:5521 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:174 [inline] _raw_spin_unlock_bh+0x12/0x30 kernel/locking/spinlock.c:207 spin_unlock_bh include/linux/spinlock.h:399 [inline] batadv_nc_purge_paths+0x2a5/0x3a0 net/batman-adv/network-coding.c:467 batadv_nc_worker+0x831/0xe50 net/batman-adv/network-coding.c:716 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Tested on: commit: 760537ca ext4: fix memory leak in ext4_fill_super git tree: https://linux.googlesource.com/linux/kernel/git/torvalds/linux refs/changes/76/10176/6 console output: https://syzkaller.appspot.com/x/log.txt?x=14589b50300000 kernel config: https://syzkaller.appspot.com/x/.config?x=c9e6832b73135046 dashboard link: https://syzkaller.appspot.com/bug?extid=c9ff4822a62eee994ea3 compiler: ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] INFO: task hung in ext4_fill_super 2021-06-16 9:56 [syzbot] INFO: task hung in ext4_fill_super syzbot 2021-06-16 16:22 ` Pavel Skripkin @ 2021-08-05 14:26 ` Pavel Skripkin 2021-08-05 14:46 ` syzbot 1 sibling, 1 reply; 7+ messages in thread From: Pavel Skripkin @ 2021-08-05 14:26 UTC (permalink / raw) To: syzbot, adilger.kernel, clang-built-linux, linux-ext4, linux-kernel, nathan, ndesaulniers, syzkaller-bugs, tytso [-- Attachment #1: Type: text/plain, Size: 2972 bytes --] On 6/16/21 12:56 PM, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: f21b807c Merge tag 'drm-fixes-2021-06-11' of git://anongit.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=165fca57d00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=30f476588412c065 > dashboard link: https://syzkaller.appspot.com/bug?extid=c9ff4822a62eee994ea3 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17d19ce0300000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=108d7988300000 > > Bisection is inconclusive: the issue happens on the oldest tested release. > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1646b8d0300000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=1546b8d0300000 > console output: https://syzkaller.appspot.com/x/log.txt?x=1146b8d0300000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+c9ff4822a62eee994ea3@syzkaller.appspotmail.com > > INFO: task syz-executor768:8567 blocked for more than 143 seconds. > Not tainted 5.13.0-rc5-syzkaller #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor768 state:D stack:27544 pid: 8567 ppid: 8423 flags:0x00004004 > Call Trace: > context_switch kernel/sched/core.c:4339 [inline] > __schedule+0x916/0x23e0 kernel/sched/core.c:5147 > schedule+0xcf/0x270 kernel/sched/core.c:5226 > schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868 > do_wait_for_common kernel/sched/completion.c:85 [inline] > __wait_for_common kernel/sched/completion.c:106 [inline] > wait_for_common kernel/sched/completion.c:117 [inline] > wait_for_completion+0x168/0x270 kernel/sched/completion.c:138 > kthread_stop+0x17a/0x720 kernel/kthread.c:642 > ext4_fill_super+0x87ac/0xdfa0 fs/ext4/super.c:5190 > mount_bdev+0x34d/0x410 fs/super.c:1368 > legacy_get_tree+0x105/0x220 fs/fs_context.c:592 > vfs_get_tree+0x89/0x2f0 fs/super.c:1498 > do_new_mount fs/namespace.c:2905 [inline] > path_mount+0x132a/0x1fa0 fs/namespace.c:3235 > do_mount fs/namespace.c:3248 [inline] > __do_sys_mount fs/namespace.c:3456 [inline] > __se_sys_mount fs/namespace.c:3433 [inline] > __x64_sys_mount+0x27f/0x300 fs/namespace.c:3433 > do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 > entry_SYSCALL_64_after_hwframe+0x44/0xae > RIP: 0033:0x445b2a > RSP: 002b:00007ffc5efbf598 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 > RAX: ffffffffffffffda RBX: 00007ffc5efbf5f0 RCX: 0000000000445b2a > RDX: 0000000020000000 RSI: 00000000200000c0 RDI: 00007ffc5efbf5b0 > RBP: 00007ffc5efbf5b0 R08: 00007ffc5efbf5f0 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000202 R12: 00000000200003f8 > R13: 0000000000000003 R14: 0000000000000004 R15: 0000000000000005 > #syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master With regards, Pavel Skripkin [-- Attachment #2: 0001-ext4-avoid-huge-mmp-update-interval-value.patch --] [-- Type: text/x-patch, Size: 1592 bytes --] From 9eb3e2f727e1c33ec39c28694a1528b9cc4a32eb Mon Sep 17 00:00:00 2001 From: Pavel Skripkin <paskripkin@gmail.com> Date: Thu, 5 Aug 2021 17:23:40 +0300 Subject: [PATCH] ext4: avoid huge mmp update interval value /* .. */ Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> --- fs/ext4/mmp.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c index bc364c119af6..2f632344d38c 100644 --- a/fs/ext4/mmp.c +++ b/fs/ext4/mmp.c @@ -7,6 +7,9 @@ #include "ext4.h" +#define EXT4_KMMP_MAX_INTERVAL 100 +#define EXT4_KMMP_MIN_INTERVAL 5 + /* Checksumming functions */ static __le32 ext4_mmp_csum(struct super_block *sb, struct mmp_struct *mmp) { @@ -140,6 +143,11 @@ static int kmmpd(void *data) unsigned long diff; int retval; + /* We should avoid unreasonale huge update interval, since it can cause + * task hung bug on umount or on error handling path in ext4_fill_super() + */ + mmp_update_interval = clamp(mmp_update_interval, EXT4_KMMP_MIN_INTERVAL, EXT4_KMMP_MAX_INTERVAL); + mmp_block = le64_to_cpu(es->s_mmp_block); mmp = (struct mmp_struct *)(bh->b_data); mmp->mmp_time = cpu_to_le64(ktime_get_real_seconds()); @@ -156,6 +164,9 @@ static int kmmpd(void *data) memcpy(mmp->mmp_nodename, init_utsname()->nodename, sizeof(mmp->mmp_nodename)); + ext4_msg(sb, KERN_INFO, "Started kmmp thread with update interval = %u\n", + mmp_update_interval); + while (!kthread_should_stop() && !sb_rdonly(sb)) { if (!ext4_has_feature_mmp(sb)) { ext4_warning(sb, "kmmpd being stopped since MMP feature" -- 2.32.0 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [syzbot] INFO: task hung in ext4_fill_super 2021-08-05 14:26 ` Pavel Skripkin @ 2021-08-05 14:46 ` syzbot 2021-08-06 7:45 ` Pavel Skripkin 0 siblings, 1 reply; 7+ messages in thread From: syzbot @ 2021-08-05 14:46 UTC (permalink / raw) To: adilger.kernel, clang-built-linux, linux-ext4, linux-kernel, nathan, ndesaulniers, paskripkin, syzkaller-bugs, tytso Hello, syzbot has tested the proposed patch and the reproducer did not trigger any issue: Reported-and-tested-by: syzbot+c9ff4822a62eee994ea3@syzkaller.appspotmail.com Tested on: commit: 251a1524 Merge tag 'scsi-fixes' of git://git.kernel.or.. git tree: upstream kernel config: https://syzkaller.appspot.com/x/.config?x=166c8f6532dd88df dashboard link: https://syzkaller.appspot.com/bug?extid=c9ff4822a62eee994ea3 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 patch: https://syzkaller.appspot.com/x/patch.diff?x=160a3301300000 Note: testing is done by a robot and is best-effort only. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] INFO: task hung in ext4_fill_super 2021-08-05 14:46 ` syzbot @ 2021-08-06 7:45 ` Pavel Skripkin 2021-08-06 10:14 ` syzbot 0 siblings, 1 reply; 7+ messages in thread From: Pavel Skripkin @ 2021-08-06 7:45 UTC (permalink / raw) To: syzbot, adilger.kernel, clang-built-linux, linux-ext4, linux-kernel, nathan, ndesaulniers, syzkaller-bugs, tytso [-- Attachment #1: Type: text/plain, Size: 845 bytes --] On 8/5/21 5:46 PM, syzbot wrote: > Hello, > > syzbot has tested the proposed patch and the reproducer did not trigger any issue: > > Reported-and-tested-by: syzbot+c9ff4822a62eee994ea3@syzkaller.appspotmail.com > > Tested on: > > commit: 251a1524 Merge tag 'scsi-fixes' of git://git.kernel.or.. > git tree: upstream > kernel config: https://syzkaller.appspot.com/x/.config?x=166c8f6532dd88df > dashboard link: https://syzkaller.appspot.com/bug?extid=c9ff4822a62eee994ea3 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 > patch: https://syzkaller.appspot.com/x/patch.diff?x=160a3301300000 > > Note: testing is done by a robot and is best-effort only. > #syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master With regards, Pavel Skripkin [-- Attachment #2: 0001-ext4-fix-kthread_should_stop-while-TASK_RUNNING.patch --] [-- Type: text/x-patch, Size: 1032 bytes --] From f31fdca900d687994a880dfd675d0a46da1eaec9 Mon Sep 17 00:00:00 2001 From: Pavel Skripkin <paskripkin@gmail.com> Date: Fri, 6 Aug 2021 10:40:31 +0300 Subject: [PATCH] ext4: fix kthread_should_stop() while TASK_RUNNING /* ... */ Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> --- fs/ext4/mmp.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c index bc364c119af6..fd1985b79a8d 100644 --- a/fs/ext4/mmp.c +++ b/fs/ext4/mmp.c @@ -183,9 +183,15 @@ static int kmmpd(void *data) } diff = jiffies - last_update_time; - if (diff < mmp_update_interval * HZ) - schedule_timeout_interruptible(mmp_update_interval * - HZ - diff); + if (diff < mmp_update_interval * HZ) { + set_current_state(TASK_INTERRUPTIBLE); + if (kthread_should_stop()) { + __set_current_state(TASK_RUNNING); + break; + } + + schedule_timeout(mmp_update_interval * HZ - diff); + } /* * We need to make sure that more than mmp_check_interval -- 2.32.0 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [syzbot] INFO: task hung in ext4_fill_super 2021-08-06 7:45 ` Pavel Skripkin @ 2021-08-06 10:14 ` syzbot 0 siblings, 0 replies; 7+ messages in thread From: syzbot @ 2021-08-06 10:14 UTC (permalink / raw) To: adilger.kernel, clang-built-linux, linux-ext4, linux-kernel, nathan, ndesaulniers, paskripkin, syzkaller-bugs, tytso Hello, syzbot has tested the proposed patch and the reproducer did not trigger any issue: Reported-and-tested-by: syzbot+c9ff4822a62eee994ea3@syzkaller.appspotmail.com Tested on: commit: 902e7f37 Merge tag 'net-5.14-rc5' of git://git.kernel... git tree: upstream kernel config: https://syzkaller.appspot.com/x/.config?x=166c8f6532dd88df dashboard link: https://syzkaller.appspot.com/bug?extid=c9ff4822a62eee994ea3 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 patch: https://syzkaller.appspot.com/x/patch.diff?x=12680c4e300000 Note: testing is done by a robot and is best-effort only. ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2021-08-06 10:14 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-06-16 9:56 [syzbot] INFO: task hung in ext4_fill_super syzbot 2021-06-16 16:22 ` Pavel Skripkin 2021-06-16 18:28 ` syzbot 2021-08-05 14:26 ` Pavel Skripkin 2021-08-05 14:46 ` syzbot 2021-08-06 7:45 ` Pavel Skripkin 2021-08-06 10:14 ` syzbot
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