syzbot

 sign-in | mailing list | source | docs
🐞 Open [1516]
≡ Subsystems
🐞 Fixed [6633]
🐞 Invalid [17003]
⬇ Missing Backports [212]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
💬 Send us feedback

INFO: task hung in ext4_map_blocks (2)

Status: auto-obsoleted due to no activity on 2025/02/23 19:47
Subsystems: ext4
[Documentation on labels]
First crash: 323d, last: 318d
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-414 INFO: task hung in ext4_map_blocks 1 2 2398d 2374d 0/1 auto-closed as invalid on 2019/09/13 20:17
android-49 INFO: task hung in ext4_map_blocks 1 C 3 2534d 2370d 0/3 public: reported C repro on 2019/04/14 08:51
upstream INFO: task hung in ext4_map_blocks (3) ext4 1 1 162d 162d 0/29 auto-obsoleted due to no activity on 2025/07/29 09:53
upstream INFO: task hung in ext4_map_blocks ext4 1 C 5 2540d 2539d 0/29 closed as dup on 2018/10/27 13:40

Sample crash report:
INFO: task kworker/u8:4:62 blocked for more than 143 seconds.
      Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4    state:D stack:25408 pid:62    tgid:62    ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6848
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905
 rwsem_down_write_slowpath+0x539/0x12a0 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write+0x1d8/0x200 kernel/locking/rwsem.c:1578
 ext4_map_blocks+0x352/0x1370 fs/ext4/inode.c:701
 mpage_map_one_extent fs/ext4/inode.c:2219 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2272 [inline]
 ext4_do_writepages+0x19a7/0x3320 fs/ext4/inode.c:2735
 ext4_writepages+0x303/0x730 fs/ext4/inode.c:2824
 do_writepages+0x1b3/0x820 mm/page-writeback.c:2702
 __writeback_single_inode+0x166/0xfa0 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x603/0xfa0 fs/fs-writeback.c:1976
 __writeback_inodes_wb+0xff/0x2e0 fs/fs-writeback.c:2047
 wb_writeback+0x73e/0xb80 fs/fs-writeback.c:2158
 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
 wb_do_writeback fs/fs-writeback.c:2315 [inline]
 wb_workfn+0x8c0/0xbc0 fs/fs-writeback.c:2343
 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task jbd2/sda1-8:5187 blocked for more than 143 seconds.
      Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:jbd2/sda1-8     state:D stack:26712 pid:5187  tgid:5187  ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6848
 io_schedule+0xbf/0x130 kernel/sched/core.c:7681
 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247
 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0xda/0x110 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:105 [inline]
 __wait_on_buffer+0x64/0x70 fs/buffer.c:123
 wait_on_buffer include/linux/buffer_head.h:414 [inline]
 jbd2_journal_commit_transaction+0x3bfa/0x6ad0 fs/jbd2/commit.c:810
 kjournald2+0x1f8/0x760 fs/jbd2/journal.c:201
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task syz-executor:5836 blocked for more than 144 seconds.
      Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:23728 pid:5836  tgid:5836  ppid:5833   flags:0x00000002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6848
 io_schedule+0xbf/0x130 kernel/sched/core.c:7681
 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247
 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0xda/0x110 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:105 [inline]
 do_get_write_access+0x933/0x1270 fs/jbd2/transaction.c:1096
 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1245
 __ext4_journal_get_write_access+0x6a/0x390 fs/ext4/ext4_jbd2.c:239
 ext4_reserve_inode_write+0x13b/0x270 fs/ext4/inode.c:5830
 __ext4_mark_inode_dirty+0x1a4/0x860 fs/ext4/inode.c:6004
 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6041
 __mark_inode_dirty+0x1f7/0xe60 fs/fs-writeback.c:2515
 generic_update_time+0xcf/0xf0 fs/inode.c:2112
 inode_update_time fs/inode.c:2125 [inline]
 __file_update_time fs/inode.c:2353 [inline]
 file_update_time+0x17d/0x1c0 fs/inode.c:2383
 ext4_page_mkwrite+0x368/0x1760 fs/ext4/inode.c:6159
 do_page_mkwrite+0x177/0x380 mm/memory.c:3176
 wp_page_shared mm/memory.c:3577 [inline]
 do_wp_page+0xc4b/0x4670 mm/memory.c:3727
 handle_pte_fault mm/memory.c:5817 [inline]
 __handle_mm_fault+0x1ade/0x2a40 mm/memory.c:5944
 handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6112
 do_user_addr_fault+0x60d/0x13f0 arch/x86/mm/fault.c:1338
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f8efe8678fc
RSP: 002b:00007ffeee62c710 EFLAGS: 00010202
RAX: 00007f8efcbc8000 RBX: 00005555567062b0 RCX: 0000000000000005
RDX: 1ffffffff0417975 RSI: 00005555566f8ad8 RDI: 0000000000000020
RBP: 00007ffeee62cc10 R08: 00005555566f8ad8 R09: 0000000000002f2e
R10: 0000000000000001 R11: 0000000000000246 R12: 00007ffeee62ca60
R13: 0000000000000004 R14: 00007ffeee62c780 R15: 00007ffeee62c850
 </TASK>
INFO: task kworker/u8:22:6477 blocked for more than 144 seconds.
      Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:22   state:D stack:24152 pid:6477  tgid:6477  ppid:2      flags:0x00004000
Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6848
 io_schedule+0xbf/0x130 kernel/sched/core.c:7681
 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247
 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0xda/0x110 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:105 [inline]
 do_get_write_access+0x933/0x1270 fs/jbd2/transaction.c:1096
 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1245
 __ext4_journal_get_write_access+0x6a/0x390 fs/ext4/ext4_jbd2.c:239
 ext4_ext_get_access+0x87/0x120 fs/ext4/extents.c:168
 ext4_convert_unwritten_extents_endio fs/ext4/extents.c:3788 [inline]
 ext4_ext_handle_unwritten_extents fs/ext4/extents.c:3932 [inline]
 ext4_ext_map_blocks+0x252d/0x5ad0 fs/ext4/extents.c:4271
 ext4_map_create_blocks fs/ext4/inode.c:516 [inline]
 ext4_map_blocks+0x457/0x1370 fs/ext4/inode.c:702
 ext4_convert_unwritten_extents+0x2b7/0x4c0 fs/ext4/extents.c:4876
 ext4_convert_unwritten_io_end_vec+0x127/0x280 fs/ext4/extents.c:4915
 ext4_end_io_end fs/ext4/page-io.c:185 [inline]
 ext4_do_flush_completed_IO fs/ext4/page-io.c:258 [inline]
 ext4_end_io_rsv_work+0x2ca/0x690 fs/ext4/page-io.c:272
 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task syz.4.2409:17073 blocked for more than 144 seconds.
      Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2409      state:D stack:27248 pid:17073 tgid:17071 ppid:10121  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6848
 io_schedule+0xbf/0x130 kernel/sched/core.c:7681
 folio_wait_bit_common+0x3d8/0x9b0 mm/filemap.c:1308
 folio_lock include/linux/pagemap.h:1151 [inline]
 mpage_prepare_extent_to_map+0xa16/0x1470 fs/ext4/inode.c:2480
 ext4_do_writepages+0xd00/0x3320 fs/ext4/inode.c:2733
 ext4_writepages+0x303/0x730 fs/ext4/inode.c:2824
 do_writepages+0x1b3/0x820 mm/page-writeback.c:2702
 filemap_fdatawrite_wbc mm/filemap.c:397 [inline]
 filemap_fdatawrite_wbc+0x104/0x160 mm/filemap.c:387
 __filemap_fdatawrite_range+0xb3/0xf0 mm/filemap.c:430
 file_write_and_wait_range+0xca/0x140 mm/filemap.c:787
 ext4_sync_file+0x290/0xf30 fs/ext4/fsync.c:158
 vfs_fsync_range+0x136/0x220 fs/sync.c:187
 __do_sys_msync+0x3c6/0x5b0 mm/msync.c:96
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fee57f7e819
RSP: 002b:00007fee58e19038 EFLAGS: 00000246 ORIG_RAX: 000000000000001a
RAX: ffffffffffffffda RBX: 00007fee58135fa0 RCX: 00007fee57f7e819
RDX: 0000000000000006 RSI: 0000002000000005 RDI: 0000000000000000
RBP: 00007fee57ff175e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fee58135fa0 R15: 00007fff4f133298
 </TASK>
INFO: task syz-executor:17225 blocked for more than 145 seconds.
      Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:26712 pid:17225 tgid:17225 ppid:5836   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6848
 io_schedule+0xbf/0x130 kernel/sched/core.c:7681
 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247
 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0xda/0x110 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:105 [inline]
 do_get_write_access+0x933/0x1270 fs/jbd2/transaction.c:1096
 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1245
 __ext4_journal_get_write_access+0x6a/0x390 fs/ext4/ext4_jbd2.c:239
 __ext4_new_inode+0x1737/0x4e90 fs/ext4/ialloc.c:1130
 ext4_mkdir+0x283/0xb70 fs/ext4/namei.c:3024
 vfs_mkdir+0x57d/0x860 fs/namei.c:4311
 do_mkdirat+0x301/0x3a0 fs/namei.c:4334
 __do_sys_mkdir fs/namei.c:4354 [inline]
 __se_sys_mkdir fs/namei.c:4352 [inline]
 __x64_sys_mkdir+0xef/0x140 fs/namei.c:4352
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f91fad7d087
RSP: 002b:00007ffdc551db98 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007ffdc551dce2 RCX: 00007f91fad7d087
RDX: 00000000021ee716 RSI: 00000000000001c0 RDI: 00007ffdc551dcd0
RBP: f49998db0aa753ff R08: 0000000000000004 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000246 R12: 8421084210842109
R13: 00007ffdc551dce2 R14: 00007f91fae12f00 R15: 00000000021ee716
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xf0c/0x1240 kernel/hung_task.c:379
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 4351 Comm: kworker/u8:9 Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline]
RIP: 0010:unwind_next_frame+0xac7/0x20c0 arch/x86/kernel/unwind_orc.c:585
Code: ff ff e8 0c e8 c2 ff e9 f0 f8 ff ff 4d 8d 7e f8 ba 08 00 00 00 4c 89 ef 4c 89 4c 24 20 4c 89 fe 48 89 4c 24 18 e8 29 f3 ff ff <4d> 8d 45 34 84 c0 0f 84 81 f8 ff ff 4c 89 ff e8 05 eb ff ff 48 89
RSP: 0018:ffffc9000fc96ee8 EFLAGS: 00000292
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffc9000fc98000
RDX: ffffc9000fc97201 RSI: ffffc9000fc972a0 RDI: ffffc9000fc96f58
RBP: ffffc9000fc96fa0 R08: ffffffff90dcd954 R09: ffffffff90dcd8fe
R10: ffffc9000fc96f58 R11: 000000000000f068 R12: ffffc9000fc96fa8
R13: ffffc9000fc96f58 R14: ffffc9000fc972a8 R15: ffffc9000fc972a0
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005627ea0fd600 CR3: 000000000dd7e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 arch_stack_walk+0x95/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4264 [inline]
 __kmalloc_noprof+0x1e8/0x410 mm/slub.c:4276
 kmalloc_noprof include/linux/slab.h:883 [inline]
 kzalloc_noprof include/linux/slab.h:1015 [inline]
 cfg80211_inform_single_bss_data+0x5b0/0x1e40 net/wireless/scan.c:2306
 cfg80211_inform_bss_data+0x254/0x3e40 net/wireless/scan.c:3189
 cfg80211_inform_bss_frame_data+0x252/0x8a0 net/wireless/scan.c:3284
 ieee80211_bss_info_update+0x311/0xab0 net/mac80211/scan.c:226
 ieee80211_rx_bss_info net/mac80211/ibss.c:1101 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1580 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x1956/0x3040 net/mac80211/ibss.c:1607
 ieee80211_iface_process_skb net/mac80211/iface.c:1616 [inline]
 ieee80211_iface_work+0xc0b/0xf00 net/mac80211/iface.c:1670
 cfg80211_wiphy_work+0x3de/0x560 net/wireless/core.c:440
 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/25 19:46 upstream 9f16d5e6f220 36dfdd05 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in ext4_map_blocks
2024/11/23 13:24 upstream 228a1157fb9f 68da6d95 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in ext4_map_blocks
2024/11/20 11:51 upstream bf9aa14fc523 7d02db5a .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in ext4_map_blocks
* Struck through repros no longer work on HEAD.