INFO: task jbd2/sda1-8:3521 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: 3521 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:4171 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:22800 pid: 4171 ppid: 4170 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: 0033:0x7f41bf5d5662 RSP: 002b:00007ffc89ffe2b0 EFLAGS: 00010246 RAX: 00007f41bd69d000 RBX: 0000555589303930 RCX: 0000000000000000 RDX: 0000000000000694 RSI: 000055558930f748 RDI: 0000000000000001 RBP: 00007ffc89ffe7b0 R08: 000055558930f760 R09: 0000000000000086 R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffc89ffe5f0 R13: 00007ffc89ffe3e0 R14: 585858582e7a7973 R15: 00007ffc89ffe330 INFO: task kworker/u4:5:4237 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:23024 pid: 4237 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+0x1c9/0x14e0 fs/ext4/mballoc.c:3871 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_old_data_flush fs/fs-writeback.c:2216 [inline] wb_do_writeback fs/fs-writeback.c:2269 [inline] wb_workfn+0xb15/0xf20 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-executor:4831 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21776 pid: 4831 ppid: 4825 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_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_new_inode+0x144f/0x3ad0 fs/ext4/ialloc.c:1100 ext4_mkdir+0x407/0xc90 fs/ext4/namei.c:3066 vfs_mkdir+0x386/0x570 fs/namei.c:4073 do_mkdirat+0x1dd/0x5c0 fs/namei.c:4098 __do_sys_mkdirat fs/namei.c:4113 [inline] __se_sys_mkdirat fs/namei.c:4111 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111 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: 0033:0x7fb395946f47 RSP: 002b:00007ffca7a04f78 EFLAGS: 00000202 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fb3959dea68 RCX: 00007fb395946f47 RDX: 00000000000001ff RSI: 00007fb3959dea68 RDI: 00000000ffffff9c RBP: 00007fb395bd07b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffca7a051e8 R15: 0000000000000000 INFO: task syz-executor:4894 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21904 pid: 4894 ppid: 4880 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_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_new_inode+0x144f/0x3ad0 fs/ext4/ialloc.c:1100 ext4_mkdir+0x407/0xc90 fs/ext4/namei.c:3066 vfs_mkdir+0x386/0x570 fs/namei.c:4073 do_mkdirat+0x1dd/0x5c0 fs/namei.c:4098 __do_sys_mkdirat fs/namei.c:4113 [inline] __se_sys_mkdirat fs/namei.c:4111 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111 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: 0033:0x7f75f33eaf47 RSP: 002b:00007ffd587e3cc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f75f3482a68 RCX: 00007f75f33eaf47 RDX: 00000000000001ff RSI: 00007f75f3482a68 RDI: 00000000ffffff9c RBP: 00007f75f36747b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffd587e3f38 R15: 0000000000000000 INFO: task syz.1.215:4927 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.215 state:D stack:27440 pid: 4927 ppid: 4187 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: 0033:0x7fa2db755789 RSP: 002b:00007fffde0623f0 EFLAGS: 00010202 RAX: 0000001b32724000 RBX: 0000000000000000 RCX: 00000000003ffde8 RDX: 0000001b32723ffc RSI: 00000000003ffde8 RDI: 00007fa2dc638700 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007fa2dbaf5000 R10: 00007fa2dc638700 R11: 0000000000000000 R12: 0000000000000000 R13: 00000000000001f1 R14: ffffffff819d3f44 R15: 00007fa2dc638720 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/3942: #0: ffff88814cd67098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 3 locks held by syz-executor/4171: #0: ffff88807c0fea28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807c0fea28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296 #1: ffff88814cfc4558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1811 [inline] #1: ffff88814cfc4558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1910 [inline] #1: ffff88814cfc4558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6194 #2: ffff88807f5d8990 (jbd2_handle){.+.+}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462 6 locks held by kworker/u4:5/4237: #0: ffff8881423fc138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000313fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffff88814cfc40e0 (&type->s_umount_key#32){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff88814cfc6c58 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691 #4: ffff88807f5d8990 (jbd2_handle){.+.+}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462 #5: ffff8880746b8c70 (&ei->i_data_sem){++++}-{3:3}, at: ext4_map_blocks+0x8c4/0x1a50 fs/ext4/inode.c:668 3 locks held by syz-executor/4831: #0: ffff88814cfc4460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386 #1: ffff88806124abd0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline] #1: ffff88806124abd0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3843 #2: ffff88807f5d8990 (jbd2_handle){.+.+}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462 3 locks held by syz-executor/4894: #0: ffff88814cfc4460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386 #1: ffff88806128e7a0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline] #1: ffff88806128e7a0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3843 #2: ffff88807f5d8990 (jbd2_handle){.+.+}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462 3 locks held by syz.1.215/4927: #0: ffff88807979c728 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807979c728 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296 #1: ffff88814cfc4558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1811 [inline] #1: ffff88814cfc4558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1910 [inline] #1: ffff88814cfc4558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6194 #2: ffff88807f5d8990 (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 CPU: 1 PID: 4230 Comm: kworker/1:4 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events kfree_rcu_work RIP: 0010:unwind_next_frame+0x3dd/0x1cf0 arch/x86/kernel/unwind_orc.c:461 Code: 06 01 49 c7 c4 a0 99 28 8a 4d 8d 7c 24 04 4d 8d 74 24 05 4d 89 fd 49 c1 ed 03 48 bd 00 00 00 00 00 fc ff df 41 0f b6 44 2d 00 <84> c0 0f 85 f0 12 00 00 4c 89 f0 48 c1 e8 03 0f b6 04 28 84 c0 0f RSP: 0018:ffffc90002e9f5d0 EFLAGS: 00000a07 RAX: 0000000000000000 RBX: ffffc90002e9f668 RCX: ffffffff8da07d14 RDX: ffffffff8e0fac5e RSI: ffffffff8da07cf4 RDI: ffffffff81350ed7 RBP: dffffc0000000000 R08: 000000000000000c R09: 0000000000000001 R10: dffffc0000000000 R11: fffff520005d3ed9 R12: ffffffff8e0fac82 R13: 1ffffffff1c1f590 R14: ffffffff8e0fac87 R15: ffffffff8e0fac86 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d898d39168 CR3: 000000002af3a000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free_bulk+0x38b/0x490 mm/slub.c:3645 kfree_bulk include/linux/slab.h:465 [inline] kfree_rcu_work+0x311/0x900 kernel/rcu/tree.c:3299 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