syzbot has found a reproducer for the following issue on: HEAD commit: 3f066e882bf1 Merge tag 'for-5.16/parisc-7' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=13aeaedbb00000 kernel config: https://syzkaller.appspot.com/x/.config?x=6104739ac5f067ea dashboard link: https://syzkaller.appspot.com/bug?extid=9c3fb12e9128b6e1d7eb compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=130e8ea5b00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15b3620db00000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+9c3fb12e9128b6e1d7eb@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task jbd2/sda1-8:2935 blocked for more than 143 seconds. Not tainted 5.16.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:24688 pid: 2935 ppid: 2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:4972 [inline] __schedule+0xb72/0x1460 kernel/sched/core.c:6253 schedule+0x12b/0x1f0 kernel/sched/core.c:6326 jbd2_journal_commit_transaction+0xc24/0x5c00 fs/jbd2/commit.c:496 kjournald2+0x4b4/0x940 fs/jbd2/journal.c:213 kthread+0x468/0x490 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8cb1de00 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3281: #0: ffff88814b4a6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002b962e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6c5/0x1c60 drivers/tty/n_tty.c:2113 2 locks held by syz-executor272/3690: #0: ffff88806d05dda8 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: iterate_dir+0x124/0x640 fs/readdir.c:55 #1: ffff88814b6d0460 (sb_writers#5){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2505 [inline] #1: ffff88814b6d0460 (sb_writers#5){.+.+}-{0:0}, at: iterate_dir+0x552/0x640 fs/readdir.c:70 2 locks held by syz-executor272/3689: #0: ffff88806d0349b8 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: iterate_dir+0x124/0x640 fs/readdir.c:55 #1: ffff88814b6d0460 (sb_writers#5){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2505 [inline] #1: ffff88814b6d0460 (sb_writers#5){.+.+}-{0:0}, at: iterate_dir+0x552/0x640 fs/readdir.c:70 3 locks held by syz-executor272/3691: #0: ffff88814b6d0460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:376 #1: ffff888074dcf198 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:818 [inline] #1: ffff888074dcf198 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: filename_create+0x1da/0x4e0 fs/namei.c:3654 #2: ffff88814b6d4990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x136d/0x1630 fs/jbd2/transaction.c:466 2 locks held by syz-executor272/3693: #0: ffff88806d0317e0 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: iterate_dir+0x124/0x640 fs/readdir.c:55 #1: ffff88814b6d0460 (sb_writers#5){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2505 [inline] #1: ffff88814b6d0460 (sb_writers#5){.+.+}-{0:0}, at: iterate_dir+0x552/0x640 fs/readdir.c:70 2 locks held by syz-executor272/3694: #0: ffff88806d0617e0 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: iterate_dir+0x124/0x640 fs/readdir.c:55 #1: ffff88814b6d0460 (sb_writers#5){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2505 [inline] #1: ffff88814b6d0460 (sb_writers#5){.+.+}-{0:0}, at: iterate_dir+0x552/0x640 fs/readdir.c:70 2 locks held by syz-executor272/3695: #0: ffff88806d035da8 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: iterate_dir+0x124/0x640 fs/readdir.c:55 #1: ffff88814b6d0460 (sb_writers#5){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2505 [inline] #1: ffff88814b6d0460 (sb_writers#5){.+.+}-{0:0}, at: iterate_dir+0x552/0x640 fs/readdir.c:70 2 locks held by kworker/u4:1/3719: 4 locks held by kworker/u4:4/3847: #0: ffff888013bf3938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7ca/0x1140 #1: ffffc90003167d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x808/0x1140 kernel/workqueue.c:2273 #2: ffff88814b6d00e0 (&type->s_umount_key#31){++++}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff88814b6d2bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1dd/0x4080 fs/ext4/inode.c:2655 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xc82/0xcd0 kernel/hung_task.c:295 kthread+0x468/0x490 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 </TASK> Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3719 Comm: kworker/u4:1 Not tainted 5.16.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:mark_lock+0x6/0x1e00 kernel/locking/lockdep.c:4566 Code: 07 80 c1 03 38 c1 0f 8c 6f ff ff ff 4c 89 ff e8 80 fb 69 00 e9 62 ff ff ff e8 26 e7 ac 08 66 0f 1f 44 00 00 55 48 89 e5 41 57 <41> 56 41 55 41 54 53 48 83 e4 e0 48 81 ec c0 01 00 00 65 48 8b 04 RSP: 0018:ffffc900029bf8e8 EFLAGS: 00000046 RAX: 0000000000000002 RBX: ffff8880217761d0 RCX: 00000000ffffffff RDX: 0000000000000008 RSI: ffff8880217761b0 RDI: ffff888021775700 RBP: ffffc900029bf8f0 R08: dffffc0000000000 R09: fffffbfff1ff3ff8 R10: fffffbfff1ff3ff8 R11: 0000000000000000 R12: 000000000000000a R13: ffff8880217761b0 R14: ffff888021775700 R15: ffff8880217761d0 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005621d6c67680 CR3: 000000000c88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> mark_usage kernel/locking/lockdep.c:4526 [inline] __lock_acquire+0xd38/0x2b00 kernel/locking/lockdep.c:4981 lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5637 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:268 rcu_read_lock include/linux/rcupdate.h:688 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0xc8/0x5b0 net/batman-adv/network-coding.c:723 process_one_work+0x853/0x1140 kernel/workqueue.c:2298 worker_thread+0xac1/0x1320 kernel/workqueue.c:2445 kthread+0x468/0x490 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 </TASK> ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 80 c1 03 add $0x3,%cl 3: 38 c1 cmp %al,%cl 5: 0f 8c 6f ff ff ff jl 0xffffff7a b: 4c 89 ff mov %r15,%rdi e: e8 80 fb 69 00 callq 0x69fb93 13: e9 62 ff ff ff jmpq 0xffffff7a 18: e8 26 e7 ac 08 callq 0x8ace743 1d: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 23: 55 push %rbp 24: 48 89 e5 mov %rsp,%rbp 27: 41 57 push %r15 * 29: 41 56 push %r14 <-- trapping instruction 2b: 41 55 push %r13 2d: 41 54 push %r12 2f: 53 push %rbx 30: 48 83 e4 e0 and $0xffffffffffffffe0,%rsp 34: 48 81 ec c0 01 00 00 sub $0x1c0,%rsp 3b: 65 gs 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 04 .byte 0x4
