INFO: task syz.8.953:10027 blocked for more than 143 seconds. Not tainted 6.15.0-syzkaller-12331-gcfc4ca8986bb #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.953 state:D stack:24968 pid:10027 tgid:10026 ppid:8062 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 netfs_wait_for_request+0x1f0/0x600 fs/netfs/misc.c:450 netfs_unbuffered_write_iter_locked+0x52a/0x910 fs/netfs/direct_write.c:110 netfs_unbuffered_write_iter+0x4c4/0x660 fs/netfs/direct_write.c:193 do_iter_readv_writev+0x56e/0x7f0 fs/read_write.c:-1 vfs_writev+0x31a/0x960 fs/read_write.c:1057 do_writev+0x14d/0x2d0 fs/read_write.c:1103 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fde4638e929 RSP: 002b:00007fde4711a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007fde465b5fa0 RCX: 00007fde4638e929 RDX: 0000000000000001 RSI: 0000200000000000 RDI: 0000000000000007 RBP: 00007fde46410b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fde465b5fa0 R15: 00007fff1335c708 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13f060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f060 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by getty/5589: #0: ffff888033ee20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 5 locks held by syz-executor/5844: 1 lock held by syz-executor/9662: 3 locks held by syz.8.953/10027: #0: ffff88807d15b7b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213 #1: ffff88804d02e428 (sb_writers#31){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3092 [inline] #1: ffff88804d02e428 (sb_writers#31){.+.+}-{0:0}, at: vfs_writev+0x288/0x960 fs/read_write.c:1055 #2: ffff888053d18e28 (&sb->s_type->i_mutex_key#41){++++}-{4:4}, at: netfs_start_io_direct+0x1ef/0x230 fs/netfs/locking.c:188 1 lock held by syz-executor/10823: #0: ffffffff8e144b78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8e144b78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 2 locks held by syz.1.1339/11538: #0: ffffffff8e891168 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline] #0: ffffffff8e891168 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690 block/bio.c:1758 #1: ffffffff8e144a40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3782 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-12331-gcfc4ca8986bb #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11644 Comm: syz.6.1362 Not tainted 6.15.0-syzkaller-12331-gcfc4ca8986bb #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:srso_alias_safe_ret+0x0/0x7 arch/x86/lib/retpoline.S:172 Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <48> 8d 64 24 08 c3 cc e8 f4 ff ff ff 0f 0b cc cc cc cc cc cc cc cc RSP: 0000:ffffc90019bc7a90 EFLAGS: 00000086 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 7bc0631ea9655f00 RDX: 0000000000000000 RSI: ffffffff8db69626 RDI: ffffffff8be28340 RBP: ffffffff822ef72d R08: 0000000000000000 R09: ffffffff822ef72d R10: dffffc0000000000 R11: ffffed1006624a7c R12: 0000000000000002 R13: ffffffff8e13f060 R14: 0000000000000000 R15: 0000000000000246 FS: 00007f1ab84596c0(0000) GS:ffff888125c55000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1aad0d6000 CR3: 00000000684ef000 CR4: 0000000000350ef0 Call Trace: srso_alias_return_thunk+0x5/0xfbef5 arch/x86/lib/retpoline.S:182 lockdep_recursion_finish kernel/locking/lockdep.c:473 [inline] lock_acquire+0x130/0x360 kernel/locking/lockdep.c:5873 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] page_table_check_set+0x1aa/0x730 mm/page_table_check.c:112 page_table_check_ptes_set include/linux/page_table_check.h:76 [inline] set_ptes+0x231/0x240 include/linux/pgtable.h:292 do_anonymous_page mm/memory.c:5142 [inline] do_pte_missing mm/memory.c:4249 [inline] handle_pte_fault mm/memory.c:6089 [inline] __handle_mm_fault+0x3c2c/0x5620 mm/memory.c:6232 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6401 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f1ab7450d46 Code: f0 72 6e 48 63 cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01 RSP: 002b:00007f1ab84584a0 EFLAGS: 00010206 RAX: 00000000002d6001 RBX: 00007f1ab8458540 RCX: 0000000000000092 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f1ab84585e0 RBP: 0000000000000102 R08: 00007f1aace00000 R09: 00000000002d6000 R10: 0000000000000000 R11: 00007f1ab8458550 R12: 0000000000000001 R13: 00007f1ab762c020 R14: 0000000000000000 R15: 00007f1ab84585e0