syzbot


INFO: task hung in write_cache_pages

Status: auto-obsoleted due to no activity on 2023/08/23 09:07
Reported-by: syzbot+0ed7e3ae33cc1917a48d@syzkaller.appspotmail.com
First crash: 407d, last: 407d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in write_cache_pages fs mm 65 2016d 2387d 0/27 closed as dup on 2017/12/12 16:30
upstream INFO: task hung in write_cache_pages (2) mm fs C done 36 408d 479d 22/27 fixed on 2023/06/08 14:41
android-44 INFO: task hung in write_cache_pages 10 2249d 2304d 0/2 auto-closed as invalid on 2019/02/22 13:49
android-49 INFO: task hung in write_cache_pages syz 17 2257d 1897d 0/3 public: reported syz repro on 2019/04/14 09:28
upstream INFO: task hung in write_cache_pages (3) gfs2 C done done 10 168d 293d 26/27 fixed on 2024/02/21 18:23

Sample crash report:
INFO: task kworker/u4:23:4921 blocked for more than 143 seconds.
      Not tainted 5.15.111-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:23   state:D stack:21176 pid: 4921 ppid:     2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:4)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 io_schedule+0x88/0x100 kernel/sched/core.c:8472
 wait_on_page_bit_common+0xa13/0x1180 mm/filemap.c:1356
 lock_page include/linux/pagemap.h:625 [inline]
 write_cache_pages+0x557/0x1160 mm/page-writeback.c:2222
 generic_writepages+0xfb/0x160 mm/page-writeback.c:2346
 do_writepages+0x481/0x730 mm/page-writeback.c:2364
 __writeback_single_inode+0x15b/0xe30 fs/fs-writeback.c:1625
 writeback_sb_inodes+0xbf0/0x1a50 fs/fs-writeback.c:1908
 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:1979
 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2084
 wb_check_start_all fs/fs-writeback.c:2206 [inline]
 wb_do_writeback fs/fs-writeback.c:2232 [inline]
 wb_workfn+0x9f4/0x1130 fs/fs-writeback.c:2266
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2307
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2454
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
INFO: task syz-executor.4:31229 blocked for more than 143 seconds.
      Not tainted 5.15.111-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:23168 pid:31229 ppid:  4798 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 io_schedule+0x88/0x100 kernel/sched/core.c:8472
 bit_wait_io+0xe/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xbf/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x1d0/0x250 kernel/sched/wait_bit.c:117
 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
 __lock_buffer fs/buffer.c:69 [inline]
 lock_buffer include/linux/buffer_head.h:402 [inline]
 __sync_dirty_buffer+0x120/0x380 fs/buffer.c:3144
 __ext4_handle_dirty_metadata+0x288/0x800 fs/ext4/ext4_jbd2.c:381
 ext4_convert_inline_data_nolock+0xad1/0xda0 fs/ext4/inline.c:1262
 ext4_convert_inline_data+0x4cf/0x610 fs/ext4/inline.c:2045
 ext4_page_mkwrite+0x1ec/0x1290 fs/ext4/inode.c:6101
 do_page_mkwrite+0x1a9/0x440 mm/memory.c:2883
 do_shared_fault mm/memory.c:4285 [inline]
 do_fault mm/memory.c:4353 [inline]
 handle_pte_fault mm/memory.c:4608 [inline]
 __handle_mm_fault mm/memory.c:4743 [inline]
 handle_mm_fault+0x2803/0x5950 mm/memory.c:4841
 do_user_addr_fault arch/x86/mm/fault.c:1397 [inline]
 handle_page_fault arch/x86/mm/fault.c:1485 [inline]
 exc_page_fault+0x271/0x740 arch/x86/mm/fault.c:1541
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568
RIP: 0010:copy_user_generic_unrolled+0x89/0xc0 arch/x86/lib/copy_user_64.S:92
Code: 38 4c 89 47 20 4c 89 4f 28 4c 89 57 30 4c 89 5f 38 48 8d 76 40 48 8d 7f 40 ff c9 75 b6 89 d1 83 e2 07 c1 e9 03 74 12 4c 8b 06 <4c> 89 07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10 89 d1 8a
RSP: 0018:ffffc90005d8fe08 EFLAGS: 00050202
RAX: ffffffff84060e01 RBX: 00000000200012c8 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffc90005d8fea0 RDI: 00000000200012c0
RBP: ffffc90005d8ff10 R08: 0000000700000006 R09: fffff52000bb1fd5
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000008
R13: 00007ffffffff000 R14: ffffc90005d8fea0 R15: 00000000200012c0
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline]
 _copy_to_user+0xef/0x130 lib/usercopy.c:40
 copy_to_user include/linux/uaccess.h:200 [inline]
 do_pipe2+0x105/0x300 fs/pipe.c:1011
 __do_sys_pipe fs/pipe.c:1032 [inline]
 __se_sys_pipe fs/pipe.c:1030 [inline]
 __x64_sys_pipe+0x36/0x40 fs/pipe.c:1030
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f7bc156f169
RSP: 002b:00007f7bbfae1168 EFLAGS: 00000246 ORIG_RAX: 0000000000000016
RAX: ffffffffffffffda RBX: 00007f7bc168ef80 RCX: 00007f7bc156f169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200012c0
RBP: 00007f7bc15caca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd4f81c0df R14: 00007f7bbfae1300 R15: 0000000000022000
 </TASK>
INFO: task udevd:31239 blocked for more than 144 seconds.
      Not tainted 5.15.111-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:25880 pid:31239 ppid:  2960 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6514
 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:817
 blkdev_open+0x138/0x2d0 block/fops.c:463
 do_dentry_open+0x807/0xfb0 fs/open.c:826
 do_open fs/namei.c:3538 [inline]
 path_openat+0x2702/0x2f20 fs/namei.c:3672
 do_filp_open+0x21c/0x460 fs/namei.c:3699
 do_sys_openat2+0x13b/0x500 fs/open.c:1211
 do_sys_open fs/open.c:1227 [inline]
 __do_sys_openat fs/open.c:1243 [inline]
 __se_sys_openat fs/open.c:1238 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1238
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f1b93e309a4
RSP: 002b:00007fff801a06a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000055d2a6bc4120 RCX: 00007f1b93e309a4
RDX: 00000000000a0800 RSI: 000055d2a6b48760 RDI: 00000000ffffff9c
RBP: 000055d2a6b48760 R08: 00000000ffffffff R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000a0800
R13: 000055d2a6b5c5a0 R14: 0000000000000001 R15: 000055d2a6b47910
 </TASK>
INFO: task syz-executor.5:31250 blocked for more than 144 seconds.
      Not tainted 5.15.111-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:25912 pid:31250 ppid: 16966 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 io_schedule+0x88/0x100 kernel/sched/core.c:8472
 bit_wait_io+0xe/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xbf/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x1d0/0x250 kernel/sched/wait_bit.c:117
 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
 __lock_buffer fs/buffer.c:69 [inline]
 lock_buffer include/linux/buffer_head.h:402 [inline]
 __block_write_full_page+0x57e/0x1090 fs/buffer.c:1789
 __writepage+0x60/0x120 mm/page-writeback.c:2320
 write_cache_pages+0xa97/0x1160 mm/page-writeback.c:2255
 generic_writepages+0xfb/0x160 mm/page-writeback.c:2346
 do_writepages+0x481/0x730 mm/page-writeback.c:2364
 filemap_fdatawrite_wbc+0x1d6/0x230 mm/filemap.c:400
 __filemap_fdatawrite_range mm/filemap.c:433 [inline]
 __filemap_fdatawrite mm/filemap.c:439 [inline]
 filemap_fdatawrite+0x12d/0x190 mm/filemap.c:444
 sync_bdevs+0x22a/0x310 block/bdev.c:1062
 ksys_sync+0xde/0x1c0 fs/sync.c:105
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fda1d198169
RSP: 002b:00007fda1b6c8168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fda1d2b8120 RCX: 00007fda1d198169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fda1d1f3ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcca9d401f R14: 00007fda1b6c8300 R15: 0000000000022000
 </TASK>
INFO: task syz-executor.2:31263 blocked for more than 144 seconds.
      Not tainted 5.15.111-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:28024 pid:31263 ppid:  3551 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191
 sync_inodes_sb+0x293/0xab0 fs/fs-writeback.c:2748
 iterate_supers+0x127/0x1e0 fs/super.c:705
 ksys_sync+0xb9/0x1c0 fs/sync.c:102
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f918c766169
RSP: 002b:00007f918ac96168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f918c886120 RCX: 00007f918c766169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f918c7c1ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffc5d5036f R14: 00007f918ac96300 R15: 0000000000022000
 </TASK>
INFO: task syz-executor.0:31266 blocked for more than 145 seconds.
      Not tainted 5.15.111-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:27648 pid:31266 ppid: 23542 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 rwsem_down_write_slowpath+0xebb/0x15c0 kernel/locking/rwsem.c:1157
 __down_write_common kernel/locking/rwsem.c:1284 [inline]
 __down_write kernel/locking/rwsem.c:1293 [inline]
 down_write+0x164/0x170 kernel/locking/rwsem.c:1542
 bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2746
 iterate_supers+0x127/0x1e0 fs/super.c:705
 ksys_sync+0xb9/0x1c0 fs/sync.c:102
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f2abdf9a169
RSP: 002b:00007f2abc4a9168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f2abe0ba1f0 RCX: 00007f2abdf9a169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f2abdff5ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd25aaf50f R14: 00007f2abc4a9300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91c5a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3256:
 #0: ffff88814b3c6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90001e962e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1da0 drivers/tty/n_tty.c:2147
3 locks held by kworker/u4:23/4921:
 #0: ffff88801559e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2280
 #1: ffffc90005137d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2282
 #2: ffff8881400620e0 (&type->s_umount_key#41){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418
2 locks held by kworker/u4:47/17164:
4 locks held by syz-executor.4/31229:
 #0: ffff88805140c728 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88805140c728 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1338 [inline]
 #0: ffff88805140c728 (&mm->mmap_lock#2){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1485 [inline]
 #0: ffff88805140c728 (&mm->mmap_lock#2){++++}-{3:3}, at: exc_page_fault+0x181/0x740 arch/x86/mm/fault.c:1541
 #1: ffff88807e248558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1742 [inline]
 #1: ffff88807e248558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1841 [inline]
 #1: ffff88807e248558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1b5/0x1290 fs/ext4/inode.c:6096
 #2: ffff888020988590 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:842 [inline]
 #2: ffff888020988590 (mapping.invalidate_lock){++++}-{3:3}, at: ext4_page_mkwrite+0x1df/0x1290 fs/ext4/inode.c:6099
 #3: ffff8880209880c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #3: ffff8880209880c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_convert_inline_data+0x3ab/0x610 fs/ext4/inline.c:2043
1 lock held by udevd/31239:
 #0: ffff88801bb13918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:817
1 lock held by syz-executor.5/31250:
 #0: ffff88801bb13918 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1a5/0x310 block/bdev.c:1050
2 locks held by syz-executor.2/31263:
 #0: ffff88807e2480e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2746
2 locks held by syz-executor.0/31266:
 #0: ffff88807e2480e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2746
2 locks held by syz-executor.1/31271:
 #0: ffff88807e2480e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2746
1 lock held by syz-executor.4/31318:
 #0: ffff88801bb13918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:817
2 locks held by syz-executor.1/31356:
 #0: ffff88807e2480e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2746
2 locks held by syz-executor.0/31391:
 #0: ffff88807e2480e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2746
2 locks held by syz-executor.5/31398:
 #0: ffff88807e2480e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2746
2 locks held by syz-executor.2/31404:
 #0: ffff88807e2480e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2746
2 locks held by syz-executor.3/31410:
 #0: ffff88807e2480e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2746
2 locks held by syz-executor.1/31428:
 #0: ffff88807e2480e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff8881470267d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2746

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.111-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6310 Comm: kworker/u4:38 Not tainted 5.15.111-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Workqueue: phy54 ieee80211_iface_work
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:50 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:178 [inline]
RIP: 0010:unwind_next_frame+0x50e/0x1fa0 arch/x86/kernel/unwind_orc.c:448
Code: 00 0f 84 a7 11 00 00 e9 bc 11 00 00 49 89 fc 49 89 fe 48 89 e8 4c 29 f0 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe <49> 8d 1c 46 48 89 d8 48 c1 e8 03 0f b6 04 10 84 c0 75 27 48 63 03
RSP: 0000:ffffc900051ceee8 EFLAGS: 00000202
RAX: 0000000000000008 RBX: ffffffff8dee7274 RCX: 0000000000000009
RDX: dffffc0000000000 RSI: ffffffff8e53e060 RDI: ffffffff8dee724c
RBP: ffffffff8dee7270 R08: 0000000000000016 R09: ffffc900051cf090
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff8dee724c
R13: ffffffff8100542e R14: ffffffff8dee724c R15: ffffc900051cefa0
FS:  0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00f926240 CR3: 0000000019edd000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack+0x36/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348
 kvfree_call_rcu+0x118/0x8a0 kernel/rcu/tree.c:3560
 cfg80211_update_known_bss+0x16b/0x9e0
 cfg80211_bss_update+0x16d/0x20d0 net/wireless/scan.c:1732
 cfg80211_inform_single_bss_frame_data net/wireless/scan.c:2449 [inline]
 cfg80211_inform_bss_frame_data+0xa13/0x20f0 net/wireless/scan.c:2482
 ieee80211_bss_info_update+0x7a6/0xc80 net/mac80211/scan.c:190
 ieee80211_rx_bss_info net/mac80211/ibss.c:1123 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1614 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x175e/0x2af0 net/mac80211/ibss.c:1643
 ieee80211_iface_process_skb net/mac80211/iface.c:1441 [inline]
 ieee80211_iface_work+0x78f/0xcc0 net/mac80211/iface.c:1495
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2307
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2454
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/05/12 16:33 linux-5.15.y b0ece631f84a ecca8a24 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in write_cache_pages
* Struck through repros no longer work on HEAD.