INFO: task syz-executor.3:5639 blocked for more than 143 seconds. Not tainted 5.15.185-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:23680 pid: 5639 ppid: 4505 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191 __writeback_inodes_sb_nr+0x1f3/0x240 fs/fs-writeback.c:2684 try_to_writeback_inodes_sb+0x96/0xc0 fs/fs-writeback.c:2732 ext4_nonda_switch fs/ext4/inode.c:2945 [inline] ext4_da_write_begin+0x213/0xb30 fs/ext4/inode.c:2972 generic_perform_write+0x2aa/0x530 mm/filemap.c:3785 ext4_buffered_write_iter+0x25f/0x3b0 fs/ext4/file.c:268 ext4_file_write_iter+0x773/0x17b0 fs/ext4/file.c:-1 __kernel_write+0x4f9/0x930 fs/read_write.c:539 __dump_emit+0x243/0x360 fs/coredump.c:943 dump_user_range+0x84/0x340 fs/coredump.c:1017 elf_core_dump+0x2ff7/0x3530 fs/binfmt_elf.c:2285 do_coredump+0x1419/0x2960 fs/coredump.c:894 get_signal+0x40a/0x12c0 kernel/signal.c:2886 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1504 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0xe9 RSP: 002b:0000000020000268 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fb85173df80 RCX: 00007fb85161eb29 RDX: 0000000000000000 RSI: 0000000020000260 RDI: 0000000000000000 RBP: 00007fb85166a47a R08: 0000000020000300 R09: 0000000020000300 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fb85173df80 R15: 00007fffbe104888 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11bfa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3933: #0: ffff88814ccdc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026462e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 3 locks held by syz-executor.0/4503: #0: ffff888078730370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1058 #1: ffff8880646335c8 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 #2: ffff88814cd24460 (sb_writers#5){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2521 [inline] #2: ffff88814cd24460 (sb_writers#5){.+.+}-{0:0}, at: iterate_dir+0x482/0x560 fs/readdir.c:70 2 locks held by syz-executor.3/4505: #0: ffff888024ebcaf0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1058 #1: ffff88806449d3b0 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 2 locks held by syz-executor.2/4509: #0: ffff888026abcd70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1058 #1: ffff88805d7f5da8 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 4 locks held by kworker/u4:5/4548: #0: ffff8880189dd938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000356fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 #3: ffffffff8c11bfa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 3 locks held by syz-executor.3/5639: #0: ffff88814cd24460 (sb_writers#5){.+.+}-{0:0}, at: do_coredump+0x13fd/0x2960 fs/coredump.c:893 #1: ffff8880645b67a0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff8880645b67a0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_buffered_write_iter+0xa6/0x3b0 fs/ext4/file.c:262 #2: ffff88814cd240e0 (&type->s_umount_key#32){++++}-{3:3}, at: try_to_writeback_inodes_sb+0x1e/0xc0 fs/fs-writeback.c:2729 3 locks held by syz-executor.0/6113: #0: ffff8880b903a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 #1: ffff8880b9027848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x512/0x810 kernel/sched/psi.c:891 #2: ffff88801b6eadb8 (&sig->wait_chldexit){....}-{2:2}, at: __wake_up_common_lock kernel/sched/wait.c:137 [inline] #2: ffff88801b6eadb8 (&sig->wait_chldexit){....}-{2:2}, at: __wake_up_sync_key+0xf0/0x180 kernel/sched/wait.c:205 1 lock held by syz-executor.3/6114: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 1 lock held by syz-executor.0/6118: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 2 locks held by syz-executor.5/6127: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 #1: ffff88807f5c83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x216/0x660 fs/jbd2/checkpoint.c:71 2 locks held by syz-executor.1/6130: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 #1: ffff88807f5c83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x216/0x660 fs/jbd2/checkpoint.c:71 2 locks held by syz-executor.1/6131: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 #1: ffff88807f5c83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x216/0x660 fs/jbd2/checkpoint.c:71 3 locks held by syz-executor.2/6137: 2 locks held by syz-executor.0/6156: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 #1: ffff88807f5c83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x216/0x660 fs/jbd2/checkpoint.c:71 2 locks held by syz-executor.0/6164: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 #1: ffff88807f5c83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x216/0x660 fs/jbd2/checkpoint.c:71 2 locks held by syz-executor.1/6168: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 #1: ffff88807f5c83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x216/0x660 fs/jbd2/checkpoint.c:71 2 locks held by syz-executor.2/6178: 2 locks held by syz-executor.5/6180: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 #1: ffff88807f5c83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x216/0x660 fs/jbd2/checkpoint.c:71 3 locks held by syz-executor.2/6185: 2 locks held by syz-executor.5/6187: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 #1: ffff88807f5c83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x216/0x660 fs/jbd2/checkpoint.c:71 2 locks held by syz-executor.0/6199: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 #1: ffff88807f5c83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x216/0x660 fs/jbd2/checkpoint.c:71 2 locks held by syz-executor.5/6204: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 #1: ffff8880b903a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 1 lock held by syz-executor.5/6206: 2 locks held by syz-executor.4/6220: 2 locks held by syz-executor.1/6225: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 #1: ffff88807f5c83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x216/0x660 fs/jbd2/checkpoint.c:71 2 locks held by syz-executor.4/6226: 1 lock held by syz-executor.2/6230: 2 locks held by syz-executor.0/6245: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 #1: ffff88807f5c83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x216/0x660 fs/jbd2/checkpoint.c:71 1 lock held by syz-executor.1/6246: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 1 lock held by syz-executor.3/6251: 1 lock held by syz-executor.2/6252: 1 lock held by syz-executor.5/6260: 1 lock held by syz-executor.4/6266: 1 lock held by syz-executor.4/6267: 1 lock held by syz-executor.2/6272: 1 lock held by syz-executor.1/6283: 1 lock held by syz-executor.0/6300: 1 lock held by syz-executor.2/6305: 1 lock held by syz-executor.5/6316: 1 lock held by syz-executor.2/6319: 1 lock held by syz-executor.1/6320: 2 locks held by syz-executor.0/6330: 1 lock held by syz-executor.5/6338: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 1 lock held by syz-executor.5/6340: 1 lock held by syz-executor.0/6357: 1 lock held by syz-executor.1/6372: 1 lock held by syz-executor.2/6375: 1 lock held by syz-executor.0/6396: 1 lock held by syz-executor.3/6404: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 1 lock held by syz-executor.1/6418: 1 lock held by syz-executor.2/6420: 1 lock held by syz-executor.5/6437: 1 lock held by syz-executor.0/6452: 2 locks held by syz-executor.2/6455: 1 lock held by syz-executor.2/6456: 1 lock held by syz-executor.5/6479: 1 lock held by syz-executor.1/6511: 1 lock held by syz-executor.2/6652: 1 lock held by syz-executor.1/6691: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 1 lock held by syz-executor.2/6747: 1 lock held by syz-executor.0/7219: 1 lock held by syz-executor.2/7821: 2 locks held by syz-executor.2/7822: 1 lock held by syz-executor.0/7825: 2 locks held by syz-executor.0/7826: 1 lock held by syz-executor.5/7838: 1 lock held by syz-executor.1/7847: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 1 lock held by syz-executor.1/7844: 1 lock held by syz-executor.3/7853: 1 lock held by syz-executor.2/7874: 1 lock held by syz-executor.5/7875: 1 lock held by syz-executor.5/7882: 1 lock held by syz-executor.1/7894: 1 lock held by syz-executor.3/7900: 1 lock held by syz-executor.0/7904: 1 lock held by syz-executor.0/7905: 1 lock held by syz-executor.3/7906: 1 lock held by syz-executor.4/7915: 1 lock held by syz-executor.2/7923: 1 lock held by syz-executor.5/7934: 1 lock held by syz-executor.3/7936: 1 lock held by syz-executor.4/7943: 1 lock held by syz-executor.1/7946: 1 lock held by syz-executor.3/7948: 1 lock held by syz-executor.2/7957: 1 lock held by syz-executor.5/7973: 3 locks held by syz-executor.0/7976: 1 lock held by syz-executor.2/7994: 1 lock held by syz-executor.2/7998: 1 lock held by syz-executor.5/8002: 1 lock held by syz-executor.0/8007: 1 lock held by syz-executor.0/8009: 3 locks held by syz-executor.3/8025: 1 lock held by syz-executor.3/8028: 1 lock held by syz-executor.4/8041: 3 locks held by syz-executor.4/8042: 5 locks held by syz-executor.2/8050: 2 locks held by syz-executor.2/8063: 2 locks held by syz-executor.3/8067: 3 locks held by syz-executor.3/8069: 1 lock held by syz-executor.0/8082: 1 lock held by syz-executor.4/8092: 2 locks held by syz-executor.5/8113: 3 locks held by syz-executor.1/8117: 1 lock held by syz-executor.1/8120: 1 lock held by syz-executor.3/8122: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 1 lock held by syz-executor.4/8141: 1 lock held by syz-executor.3/8177: 1 lock held by syz-executor.5/8181: 1 lock held by syz-executor.0/8185: 2 locks held by syz-executor.3/8188: 3 locks held by syz-executor.0/8195: 1 lock held by syz-executor.1/8205: 3 locks held by syz-executor.4/8212: 1 lock held by syz-executor.1/8214: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 2 locks held by syz-executor.2/8235: 3 locks held by syz-executor.3/8237: 1 lock held by syz-executor.0/8254: 2 locks held by syz-executor.0/8256: 1 lock held by syz-executor.1/8259: #0: ffff88814cd26bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1c0/0x2d20 fs/ext4/inode.c:2689 1 lock held by syz-executor.1/8260: 2 locks held by syz-executor.0/8271: 1 lock held by syz-executor.1/8283: 1 lock held by syz-executor.3/8286: 3 locks held by syz-executor.3/8289: 4 locks held by syz-executor.3/8597: 1 lock held by syz-executor.1/8623: #0: ffffffff8c120a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #0: ffffffff8c120a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845 4 locks held by syz-executor.0/8845: 1 lock held by syz-executor.5/9143: #0: ffffffff8c120a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #0: ffffffff8c120a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x320/0x6b0 kernel/rcu/tree_exp.h:845 4 locks held by syz-executor.2/9149: 2 locks held by syz-executor.2/9495: 4 locks held by syz-executor.3/9549: 3 locks held by syz-executor.4/9674: 2 locks held by syz-executor.4/9949: 2 locks held by syz-executor.4/9951: 4 locks held by syz-executor.0/9957: 5 locks held by syz-executor.3/9999: 3 locks held by syz-executor.2/10006: 4 locks held by syz-executor.3/10007: 3 locks held by syz-executor.0/10071: 1 lock held by syz-executor.2/10095: 2 locks held by syz-executor.4/10099: #0: ffff88814cd24460 (sb_writers#5){.+.+}-{0:0}, at: do_coredump+0x13fd/0x2960 fs/coredump.c:893 #1: ffff888057f903f0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff888057f903f0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_buffered_write_iter+0xa6/0x3b0 fs/ext4/file.c:262 2 locks held by syz-executor.3/10133: 2 locks held by syz-executor.0/10149: #0: ffff88814cd24460 (sb_writers#5){.+.+}-{0:0}, at: do_coredump+0x13fd/0x2960 fs/coredump.c:893 #1: ffff8880644a8de8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff8880644a8de8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_buffered_write_iter+0xa6/0x3b0 fs/ext4/file.c:262 2 locks held by syz-executor.4/10180: #0: ffff88814cd24460 (sb_writers#5){.+.+}-{0:0}, at: do_coredump+0x13fd/0x2960 fs/coredump.c:893 #1: ffff888048290de8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff888048290de8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_buffered_write_iter+0xa6/0x3b0 fs/ext4/file.c:262 2 locks held by syz-executor.3/10181: #0: ffff88814cd24460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:377 #1: ffff888057f9abd0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline] #1: ffff888057f9abd0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: filename_create+0x1f2/0x450 fs/namei.c:3835 3 locks held by syz-executor.4/10195: #0: ffff88814cd24460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:377 #1: ffff888057f7bfc0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline] #1: ffff888057f7bfc0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: do_unlinkat+0x1b9/0x6f0 fs/namei.c:4331 #2: ffff888048290de8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #2: ffff888048290de8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: vfs_unlink+0xee/0x600 fs/namei.c:4269 3 locks held by syz-executor.2/10210: #0: ffff88814cd24460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:377 #1: ffff888057f9dda8 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline] #1: ffff888057f9dda8 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: filename_create+0x1f2/0x450 fs/namei.c:3835 #2: ffff88807f5c83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_log_do_checkpoint+0xacb/0xe20 fs/jbd2/checkpoint.c:243 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 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+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 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: 7936 Comm: syz-executor.3 Not tainted 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:174 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x2c/0x60 kernel/kcov.c:206 Code: 04 24 65 48 8b 0d 94 ad 8a 7e 65 8b 15 95 ad 8a 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c <8b> 91 10 16 00 00 83 fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 48 RSP: 0018:ffffc9000315f1d8 EFLAGS: 00000246 RAX: ffffffff819e29a3 RBX: ffffc9000315f240 RCX: ffff8880191bd940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffffc9000315f300 R08: dffffc0000000000 R09: fffff940003191ef R10: fffff940003191ef R11: 1ffffd40003191ee R12: 0000000000000989 R13: 0000000000000000 R14: dffffc0000000000 R15: ffffea00018c8f40 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555916d0788 CR3: 0000000021c83000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: find_get_entry mm/filemap.c:1996 [inline] find_get_pages_range+0x303/0x620 mm/filemap.c:2163 pagevec_lookup_range+0x30/0x70 mm/swap.c:1104 mpage_map_and_submit_buffers fs/ext4/inode.c:2344 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2500 [inline] ext4_writepages+0x160c/0x2d20 fs/ext4/inode.c:2829 do_writepages+0x48d/0x6d0 mm/page-writeback.c:2386 filemap_fdatawrite_wbc+0x1eb/0x240 mm/filemap.c:400 __filemap_fdatawrite_range mm/filemap.c:433 [inline] __filemap_fdatawrite mm/filemap.c:439 [inline] filemap_flush+0xb3/0x100 mm/filemap.c:466 ext4_release_file+0x7e/0x310 fs/ext4/file.c:141 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x616/0x20a0 kernel/exit.c:874 do_group_exit+0x12e/0x300 kernel/exit.c:996 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1504 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 002b:0000000020000048 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fb85173df80 RCX: 00007fb85161eb29 RDX: 0000000020000140 RSI: 0000000020000040 RDI: 0000000000008000 RBP: 00007fb85166a47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 000000000000000b R14: 00007fb85173df80 R15: 00007fffbe104888