INFO: task jbd2/sda1-8:3520 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:25872 pid: 3520 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit kernel/sched/wait_bit.c:49 [inline] out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64 wait_on_buffer include/linux/buffer_head.h:390 [inline] jbd2_journal_commit_transaction+0x2f0b/0x5c30 fs/jbd2/commit.c:848 kjournald2+0x45a/0x900 fs/jbd2/journal.c:213 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INFO: task syz-executor:4173 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:23248 pid: 4173 ppid: 4172 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit kernel/sched/wait_bit.c:49 [inline] out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x134/0xe40 fs/jbd2/transaction.c:1116 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1251 __ext4_journal_get_write_access+0x24d/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x203/0x2e0 fs/ext4/inode.c:5866 __ext4_mark_inode_dirty+0x136/0x6c0 fs/ext4/inode.c:6040 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6077 __mark_inode_dirty+0x2c8/0xc90 fs/fs-writeback.c:2480 generic_update_time+0x1cd/0x1f0 fs/inode.c:1881 inode_update_time fs/inode.c:1894 [inline] file_update_time+0x3c0/0x440 fs/inode.c:2083 ext4_page_mkwrite+0x1bc/0x1250 fs/ext4/inode.c:6195 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 wp_page_shared+0x163/0x6c0 mm/memory.c:3259 handle_pte_fault mm/memory.c:4668 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1fbd/0x4440 mm/memory.c:4883 do_user_addr_fault+0x494/0xc90 arch/x86/mm/fault.c:1355 handle_page_fault arch/x86/mm/fault.c:1443 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x7f20148fa1e3 RSP: 002b:00007ffe815a6d90 EFLAGS: 00010202 RAX: 00007f200e489f18 RBX: 00007ffe815a6ec0 RCX: 0000000000000000 RDX: 00007f200e489f14 RSI: 0000000000000008 RDI: 00007ffe815a6ec0 RBP: 00000000000003e6 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffe815a6ea0 R11: 0000000000000000 R12: 0000000000000000 R13: 00000000000000e8 R14: ffffffffffffff18 R15: 0000000000000000 INFO: task kworker/u4:5:4252 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:22096 pid: 4252 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit kernel/sched/wait_bit.c:49 [inline] out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x134/0xe40 fs/jbd2/transaction.c:1116 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1251 __ext4_journal_get_write_access+0x24d/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_mb_mark_diskspace_used+0x27d/0x14e0 fs/ext4/mballoc.c:3885 ext4_mb_new_blocks+0x11ab/0x47c0 fs/ext4/mballoc.c:5806 ext4_ext_map_blocks+0x17d1/0x63d0 fs/ext4/extents.c:4372 ext4_map_blocks+0x97f/0x1a50 fs/ext4/inode.c:675 mpage_map_one_extent fs/ext4/inode.c:2410 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2463 [inline] ext4_writepages+0x124a/0x2d40 fs/ext4/inode.c:2831 do_writepages+0x493/0x700 mm/page-writeback.c:2386 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657 writeback_sb_inodes+0xaaa/0x1750 fs/fs-writeback.c:1940 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2011 wb_writeback+0x45e/0xbc0 fs/fs-writeback.c:2116 wb_check_start_all fs/fs-writeback.c:2238 [inline] wb_do_writeback fs/fs-writeback.c:2264 [inline] wb_workfn+0x924/0xf20 fs/fs-writeback.c:2298 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INFO: task syz.2.224:5185 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.224 state:D stack:26288 pid: 5185 ppid: 4194 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit kernel/sched/wait_bit.c:49 [inline] out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x134/0xe40 fs/jbd2/transaction.c:1116 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1251 __ext4_journal_get_write_access+0x24d/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x203/0x2e0 fs/ext4/inode.c:5866 __ext4_mark_inode_dirty+0x136/0x6c0 fs/ext4/inode.c:6040 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6077 __mark_inode_dirty+0x2c8/0xc90 fs/fs-writeback.c:2480 generic_update_time+0x1cd/0x1f0 fs/inode.c:1881 inode_update_time fs/inode.c:1894 [inline] file_update_time+0x3c0/0x440 fs/inode.c:2083 ext4_page_mkwrite+0x1bc/0x1250 fs/ext4/inode.c:6195 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 do_shared_fault mm/memory.c:4328 [inline] do_fault mm/memory.c:4396 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1e47/0x4440 mm/memory.c:4883 do_user_addr_fault+0x494/0xc90 arch/x86/mm/fault.c:1355 handle_page_fault arch/x86/mm/fault.c:1443 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x7fc357a06809 RSP: 002b:00007fff9dad5270 EFLAGS: 00010202 RAX: 0000001b32623440 RBX: fffffffffffff440 RCX: ffffffff819d5f47 RDX: 0000001b3262343c RSI: 0000000000000004 RDI: 00007fc3588e9720 RBP: 0000000000000000 R08: 00007fc357da4000 R09: 00007fc357da6000 R10: 00000000819d5f4b R11: 0000000000000017 R12: 0000000000000000 R13: 00000000000275ed R14: ffffffff819d5b94 R15: 00007fc3588e9720 INFO: task syz.2.224:5196 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.224 state:D stack:23264 pid: 5196 ppid: 4194 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 wait_on_page_bit_common+0x8bf/0xeb0 mm/filemap.c:1356 wait_on_page_writeback+0x122/0x180 mm/page-writeback.c:2909 shrink_page_list+0x5ba1/0x6de0 mm/vmscan.c:1516 shrink_inactive_list mm/vmscan.c:2223 [inline] shrink_list mm/vmscan.c:2450 [inline] shrink_lruvec+0x1315/0x2410 mm/vmscan.c:2769 shrink_node_memcgs mm/vmscan.c:2956 [inline] shrink_node+0x1190/0x2790 mm/vmscan.c:3079 shrink_zones mm/vmscan.c:3285 [inline] do_try_to_free_pages+0x60e/0x1600 mm/vmscan.c:3340 try_to_free_mem_cgroup_pages+0x347/0x800 mm/vmscan.c:3654 mem_cgroup_resize_max+0x2f7/0x3c0 mm/memcontrol.c:3414 mem_cgroup_write+0x1ee/0x230 mm/memcontrol.c:-1 cgroup_file_write+0x2c4/0x670 kernel/cgroup/cgroup.c:3967 kernfs_fop_write_iter+0x3a8/0x500 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2179 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x748/0xd70 fs/read_write.c:594 ksys_write+0x153/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc357b32159 RSP: 002b:00007fc355d48028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc357dba180 RCX: 00007fc357b32159 RDX: 0000000000000001 RSI: 0000200000000080 RDI: 000000000000000a RBP: 00007fc357bc9024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc357dba218 R14: 00007fc357dba180 R15: 00007fff9dad5228 INFO: task syz.1.233:5198 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.233 state:D stack:27696 pid: 5198 ppid: 4186 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit kernel/sched/wait_bit.c:49 [inline] out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x134/0xe40 fs/jbd2/transaction.c:1116 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1251 __ext4_journal_get_write_access+0x24d/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x203/0x2e0 fs/ext4/inode.c:5866 __ext4_mark_inode_dirty+0x136/0x6c0 fs/ext4/inode.c:6040 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6077 __mark_inode_dirty+0x2c8/0xc90 fs/fs-writeback.c:2480 generic_update_time+0x1cd/0x1f0 fs/inode.c:1881 inode_update_time fs/inode.c:1894 [inline] file_update_time+0x3c0/0x440 fs/inode.c:2083 ext4_page_mkwrite+0x1bc/0x1250 fs/ext4/inode.c:6195 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 do_shared_fault mm/memory.c:4328 [inline] do_fault mm/memory.c:4396 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1e47/0x4440 mm/memory.c:4883 do_user_addr_fault+0x494/0xc90 arch/x86/mm/fault.c:1355 handle_page_fault arch/x86/mm/fault.c:1443 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x7ffbd509d7a9 RSP: 002b:00007ffd0985c4c0 EFLAGS: 00010202 RAX: 0000001b32523000 RBX: ffffffff82f45263 RCX: 0000001b32522ff8 RDX: 0000001b32124220 RSI: 0000000000000008 RDI: 00007ffbd5f80720 RBP: 00000000000001bf R08: 00007ffbd543b000 R09: 00007ffbd543d000 R10: 0000000082f45267 R11: 000000000000001c R12: 00007ffbd5451218 R13: 0000000000001e53 R14: ffffffff82f45cdd R15: 00007ffbd5f80720 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3949: #0: ffff88802c13f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 3 locks held by syz-executor/4173: #0: ffff88807a5f6328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807a5f6328 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296 #1: ffff88814cf60558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline] #1: ffff88814cf60558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline] #1: ffff88814cf60558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6194 #2: ffff88814cf64990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462 6 locks held by kworker/u4:5/4252: #0: ffff8881421c8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000322fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffff88814cf600e0 (&type->s_umount_key#32){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff88814cf62c58 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691 #4: ffff88814cf64990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462 #5: ffff8880213a4840 (&ei->i_data_sem){++++}-{3:3}, at: ext4_map_blocks+0x8c4/0x1a50 fs/ext4/inode.c:668 3 locks held by syz.2.224/5185: #0: ffff88807e24ce28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock+0x1c/0x50 include/linux/mmap_lock.h:117 #1: ffff88814cf60558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline] #1: ffff88814cf60558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline] #1: ffff88814cf60558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6194 #2: ffff88814cf64990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462 4 locks held by syz.2.224/5196: #0: ffff88801f6b4870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88801abac460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590 #2: ffff8880282c0c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x500 fs/kernfs/file.c:287 #3: ffff8880295a8bd0 (kn->active#259){++++}-{0:0}, at: kernfs_fop_write_iter+0x1fd/0x500 fs/kernfs/file.c:288 3 locks held by syz.1.233/5198: #0: ffff88807ae8ce28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807ae8ce28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296 #1: ffff88814cf60558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline] #1: ffff88814cf60558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline] #1: ffff88814cf60558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6194 #2: ffff88814cf64990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe1b/0xe60 kernel/hung_task.c:369 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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 default_idle+0xb/0x10 arch/x86/kernel/process.c:729