INFO: task syz.1.17:6781 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.17 state:D stack:28088 pid:6781 tgid:6780 ppid:6404 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x1472/0x4fe0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1027 [inline] blkdev_fallocate+0x263/0x550 block/fops.c:908 vfs_fallocate+0x672/0x7f0 fs/open.c:339 ksys_fallocate fs/open.c:363 [inline] __do_sys_fallocate fs/open.c:368 [inline] __se_sys_fallocate fs/open.c:366 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:366 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efe9f8e03b9 RSP: 002b:00007efe9eb4e028 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007efe9fae5fa0 RCX: 00007efe9f8e03b9 RDX: 0000000000000c00 RSI: 0000000000000011 RDI: 0000000000000004 RBP: 00007efe9f96b8ec R08: 0000000000000000 R09: 0000000000000000 R10: 0020000001002000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007efe9fae5fa0 R15: 00007ffd1bced578 INFO: task syz.0.16:6784 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.16 state:D stack:27096 pid:6784 tgid:6783 ppid:6398 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x1472/0x4fe0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1027 [inline] blkdev_fallocate+0x263/0x550 block/fops.c:908 vfs_fallocate+0x672/0x7f0 fs/open.c:339 ksys_fallocate fs/open.c:363 [inline] __do_sys_fallocate fs/open.c:368 [inline] __se_sys_fallocate fs/open.c:366 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:366 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd5850903b9 RSP: 002b:00007fd5842fe028 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007fd585295fa0 RCX: 00007fd5850903b9 RDX: 0000000000000c00 RSI: 0000000000000011 RDI: 0000000000000004 RBP: 00007fd58511b8ec R08: 0000000000000000 R09: 0000000000000000 R10: 0020000001002000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd585295fa0 R15: 00007ffef921a008 INFO: task syz.2.18:6791 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.18 state:D stack:28088 pid:6791 tgid:6788 ppid:6408 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x1472/0x4fe0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1027 [inline] blkdev_fallocate+0x263/0x550 block/fops.c:908 vfs_fallocate+0x672/0x7f0 fs/open.c:339 ksys_fallocate fs/open.c:363 [inline] __do_sys_fallocate fs/open.c:368 [inline] __se_sys_fallocate fs/open.c:366 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:366 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fca68fb03b9 RSP: 002b:00007fca6821e028 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007fca691b5fa0 RCX: 00007fca68fb03b9 RDX: 0000000000000c00 RSI: 0000000000000011 RDI: 0000000000000004 RBP: 00007fca6903b8ec R08: 0000000000000000 R09: 0000000000000000 R10: 0020000001002000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fca691b5fa0 R15: 00007fff2b36ddf8 INFO: task syz.4.20:6790 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.20 state:D stack:28088 pid:6790 tgid:6789 ppid:6409 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x1472/0x4fe0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1027 [inline] blkdev_fallocate+0x263/0x550 block/fops.c:908 vfs_fallocate+0x672/0x7f0 fs/open.c:339 ksys_fallocate fs/open.c:363 [inline] __do_sys_fallocate fs/open.c:368 [inline] __se_sys_fallocate fs/open.c:366 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:366 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faecacc03b9 RSP: 002b:00007faec9f2e028 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007faecaec5fa0 RCX: 00007faecacc03b9 RDX: 0000000000000c00 RSI: 0000000000000011 RDI: 0000000000000004 RBP: 00007faecad4b8ec R08: 0000000000000000 R09: 0000000000000000 R10: 0020000001002000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007faecaec5fa0 R15: 00007ffdfe9a7a88 Showing all locks held in the system: 3 locks held by kworker/0:0/9: 4 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/38: #0: ffffffff8dbc77c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8dbc77c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8dbc77c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 6 locks held by kworker/u8:7/1359: 3 locks held by kworker/u8:8/1534: 2 locks held by getty/5556: #0: ffff88823bf260a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by syz.3.19/6766: 1 lock held by syz.1.17/6781: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.0.16/6784: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.2.18/6791: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.4.20/6790: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 3 locks held by kworker/0:6/6792: 1 lock held by syz.5.21/6954: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.7.23/6956: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.6.22/6958: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.8.24/6961: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.9.25/6963: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 7 locks held by kworker/u8:12/6965: 1 lock held by syz.3.26/7057: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.0.27/7059: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.2.29/7079: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.1.28/7084: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.4.30/7087: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 3 locks held by kworker/u8:13/7146: 1 lock held by syz.5.31/7195: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.7.32/7197: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.6.33/7229: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.8.34/7231: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.9.35/7233: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.3.36/7335: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.0.37/7337: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.2.38/7353: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.1.39/7355: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 1 lock held by syz.4.40/7357: #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff888025084868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:908 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6965 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x80 kernel/kcov.c:216 Code: 8b 3d a4 31 9a 0b 48 89 de 5b e9 93 fe 58 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 88 3b 62 10 65 8b 35 a9 3b 62 10 81 e6 00 00 ff 00 ba RSP: 0018:ffffc900054076a8 EFLAGS: 00000046 RAX: ffffffff822ed01e RBX: 0000000000000000 RCX: ffff8880257c5ac0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1e8fbcf R12: 0000000000000000 R13: 0000000000000000 R14: ffff88813fe65558 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881266c9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4f82d5db00 CR3: 000000000d9b4000 CR4: 00000000003526f0 Call Trace: __page_table_check_ptes_set+0x23e/0x320 mm/page_table_check.c:209 page_table_check_ptes_set include/linux/page_table_check.h:76 [inline] set_ptes include/linux/pgtable.h:292 [inline] __text_poke+0x948/0x990 arch/x86/kernel/alternative.c:2535 text_poke arch/x86/kernel/alternative.c:2610 [inline] smp_text_poke_batch_finish+0x923/0x1160 arch/x86/kernel/alternative.c:2943 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:879 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340 worker_thread+0xda6/0x1360 kernel/workqueue.c:3421 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246