Hello, syzbot found the following issue on: HEAD commit: c664e16bb1ba Merge tag 'docs-6.8-fixes2' of git://git.lwn... git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=13d7d01c180000 kernel config: https://syzkaller.appspot.com/x/.config?x=1d7c92dd8d5c7a1e dashboard link: https://syzkaller.appspot.com/bug?extid=65b1e2d8f2d618a93e96 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1778ca10180000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12762720180000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/3bccfc692e21/disk-c664e16b.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/197da43ba3e0/vmlinux-c664e16b.xz kernel image: https://storage.googleapis.com/syzbot-assets/b24c7a9a54fd/bzImage-c664e16b.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/0988c022ebbd/mount_0.gz The issue was bisected to: commit e994f5b677ee016a2535d9df826315122da1ae65 Author: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx> Date: Wed May 17 14:18:19 2023 +0000 squashfs: cache partial compressed blocks bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1101e584180000 final oops: https://syzkaller.appspot.com/x/report.txt?x=1301e584180000 console output: https://syzkaller.appspot.com/x/log.txt?x=1501e584180000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+65b1e2d8f2d618a93e96@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: e994f5b677ee ("squashfs: cache partial compressed blocks") INFO: task syz-executor382:5067 blocked for more than 143 seconds. Not tainted 6.8.0-rc4-syzkaller-00005-gc664e16bb1ba #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor382 state:D stack:24216 pid:5067 tgid:5067 ppid:5064 flags:0x00004002 Call Trace: <TASK> context_switch kernel/sched/core.c:5400 [inline] __schedule+0x17d1/0x49f0 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0x149/0x260 kernel/sched/core.c:6817 io_schedule+0x8c/0x110 kernel/sched/core.c:9023 folio_wait_bit_common+0x881/0x12b0 mm/filemap.c:1274 truncate_inode_pages_range+0xa8b/0xf70 mm/truncate.c:412 evict+0x2bd/0x630 fs/inode.c:667 dispose_list fs/inode.c:698 [inline] evict_inodes+0x5f8/0x690 fs/inode.c:748 generic_shutdown_super+0x9d/0x2d0 fs/super.c:631 kill_block_super+0x44/0x90 fs/super.c:1680 deactivate_locked_super+0xc6/0x130 fs/super.c:477 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1267 task_work_run+0x250/0x310 kernel/task_work.c:180 ptrace_notify+0x2d1/0x380 kernel/signal.c:2390 ptrace_report_syscall include/linux/ptrace.h:411 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:473 [inline] syscall_exit_work+0xbb/0x170 kernel/entry/common.c:167 syscall_exit_to_user_mode_prepare kernel/entry/common.c:194 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:199 [inline] syscall_exit_to_user_mode+0x27f/0x370 kernel/entry/common.c:212 do_syscall_64+0x108/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f0f31f293c7 RSP: 002b:00007fff0cb79da8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f0f31f293c7 RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007fff0cb79e60 RBP: 00007fff0cb79e60 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000202 R12: 00007fff0cb7aed0 R13: 00005555560276c0 R14: 0000000000000007 R15: 431bde82d7b634db </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/28: #0: ffffffff8e130ae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8e130ae0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8e130ae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by getty/4820: #0: ffff88802fed20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 1 lock held by syz-executor382/5067: #0: ffff88801193e0e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88801193e0e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88801193e0e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:509 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.8.0-rc4-syzkaller-00005-gc664e16bb1ba #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfaf/0xff0 kernel/hung_task.c:379 kthread+0x2f1/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 </TASK> Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 60 Comm: kworker/u4:4 Not tainted 6.8.0-rc4-syzkaller-00005-gc664e16bb1ba #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:smp_call_function_many_cond+0x2200/0x2960 kernel/smp.c:778 Code: 0f 85 03 02 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d e9 01 db e9 09 e8 9c c6 0b 00 e9 47 e0 ff ff 65 8b 1d c8 e1 7a 7e <31> ff 89 de e8 c7 ca 0b 00 85 db 0f 84 12 01 00 00 e8 7a c6 0b 00 RSP: 0018:ffffc900015b7720 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff94482303 RDX: ffff8880187d0000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900015b7920 R08: ffffffff818797a2 R09: 1ffffffff1f0ab4d R10: dffffc0000000000 R11: fffffbfff1f0ab4e R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff8f855a68 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005612dea05600 CR3: 000000002bc1a000 CR4: 0000000000350ef0 Call Trace: <NMI> </NMI> <TASK> on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2087 [inline] text_poke_bp_batch+0x726/0xb30 arch/x86/kernel/alternative.c:2359 text_poke_flush arch/x86/kernel/alternative.c:2488 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2495 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xce/0x1c0 kernel/jump_label.c:235 static_key_disable+0x1a/0x20 kernel/jump_label.c:243 toggle_allocation_gate+0x1b8/0x250 mm/kfence/core.c:831 process_one_work kernel/workqueue.c:2633 [inline] process_scheduled_works+0x915/0x1420 kernel/workqueue.c:2706 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787 kthread+0x2f1/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 </TASK> INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.016 msecs --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
