Hello, syzbot found the following issue on:
HEAD commit: 8c9660f65153 Add linux-next specific files for 20231124 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=1006f178e80000 kernel config: https://syzkaller.appspot.com/x/.config?x=ca1e8655505e280 dashboard link: https://syzkaller.appspot.com/bug?extid=ed812ed461471ab17a0c compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14ec6e62e80000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11964f7ce80000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/345ed4af3a0d/disk-8c9660f6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/191053c69d57/vmlinux-8c9660f6.xz kernel image: https://storage.googleapis.com/syzbot-assets/aac7ee5e55e0/bzImage-8c9660f6.xz The issue was bisected to: commit 0d345996e4cb573f8cc81d49b3ee9a7fd2035bef Author: Pengfei Xu <pengfei...@intel.com> Date: Mon Jul 31 03:04:18 2023 +0000 x86/kernel: increase kcov coverage under arch/x86/kernel folder bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14782eaae80000 final oops: https://syzkaller.appspot.com/x/report.txt?x=16782eaae80000 console output: https://syzkaller.appspot.com/x/log.txt?x=12782eaae80000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ed812ed461471ab17...@syzkaller.appspotmail.com Fixes: 0d345996e4cb ("x86/kernel: increase kcov coverage under arch/x86/kernel folder") INFO: task syz-executor216:5234 blocked for more than 143 seconds. Not tainted 6.7.0-rc2-next-20231124-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor216 state:D stack:29104 pid:5234 tgid:5232 ppid:5106 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5399 [inline] __schedule+0xf15/0x5c00 kernel/sched/core.c:6726 __schedule_loop kernel/sched/core.c:6801 [inline] schedule+0xe7/0x270 kernel/sched/core.c:6816 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6873 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x5b4/0x9c0 kernel/locking/mutex.c:747 blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:736 blkdev_common_ioctl+0x1575/0x1ce0 block/ioctl.c:562 blkdev_ioctl+0x249/0x770 block/ioctl.c:627 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a RIP: 0033:0x7f914d80ca89 RSP: 002b:00007f914cfa3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f914d89c1d8 RCX: 00007f914d80ca89 RDX: 0000000000000000 RSI: 0000000000001276 RDI: 0000000000000004 RBP: 00007f914d89c1d0 R08: 00007ffdb3560fd7 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f914d89c1dc R13: 000000000000006e R14: 00007ffdb3560ef0 R15: 00007ffdb3560fd8 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cfacf60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #0: ffffffff8cfacf60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #0: ffffffff8cfacf60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613 1 lock held by klogd/4501: #0: ffff8880b993c718 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:558 2 locks held by getty/4815: #0: ffff8880273ee0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc4/0x1490 drivers/tty/n_tty.c:2201 2 locks held by kworker/0:5/5180: 2 locks held by syz-executor216/5233: 1 lock held by syz-executor216/5234: #0: ffff888142f94490 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:736 1 lock held by syz-executor216/5240: #0: ffff888142f94490 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:736 1 lock held by syz-executor216/5241: #0: ffff888142f94490 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:736 1 lock held by syz-executor216/5245: #0: ffff888142f94490 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:736 1 lock held by syz-executor216/5246: #0: ffff888142f94490 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:736 1 lock held by syz-executor216/5248: #0: ffff888142f94490 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:736 1 lock held by syz-executor216/5249: #0: ffff888142f94490 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:736 1 lock held by syz-executor216/5251: #0: ffff888142f94490 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:736 1 lock held by syz-executor216/5252: #0: ffff888142f94490 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:736 1 lock held by syz-executor216/5254: #0: ffff888142f94490 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:736 1 lock held by syz-executor216/5255: #0: ffff888142f94490 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:736 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.7.0-rc2-next-20231124-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x299/0x300 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+0xf86/0x1210 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 </TASK> Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5233 Comm: syz-executor216 Not tainted 6.7.0-rc2-next-20231124-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 RIP: 0010:__sanitizer_cov_trace_switch+0x4f/0x90 kernel/kcov.c:341 Code: 83 f8 10 75 2f 41 bd 03 00 00 00 4c 8b 75 00 31 db 4d 85 f6 74 1e 48 8b 74 dd 10 4c 89 e2 4c 89 ef 48 83 c3 01 48 8b 4c 24 28 <e8> 2c fe ff ff 49 39 de 75 e2 5b 5d 41 5c 41 5d 41 5e c3 48 83 f8 RSP: 0018:ffffc90003fdf3a0 EFLAGS: 00000202 RAX: 0000000000000008 RBX: 0000000000000001 RCX: ffffffff813a44c8 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffffffff8ac9d800 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: dffffc0000000000 R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000003 R15: 0000000000000001 FS: 00007f914cfc46c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f914d899f18 CR3: 00000000a0ad4000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> unwind_next_frame+0xea8/0x2390 arch/x86/kernel/unwind_orc.c:641 arch_stack_walk+0xfa/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 save_stack+0x15e/0x1f0 mm/page_owner.c:130 __set_page_owner+0x1f/0x60 mm/page_owner.c:196 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1533 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0xa16/0x3690 mm/page_alloc.c:3344 __alloc_pages+0x22d/0x2400 mm/page_alloc.c:4600 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133 relay_alloc_buf kernel/relay.c:121 [inline] relay_create_buf kernel/relay.c:162 [inline] relay_open_buf.part.0+0x27d/0xba0 kernel/relay.c:384 relay_open_buf kernel/relay.c:536 [inline] relay_open+0x641/0xab0 kernel/relay.c:517 do_blk_trace_setup+0x4a9/0xaa0 kernel/trace/blktrace.c:591 __blk_trace_setup+0xd8/0x180 kernel/trace/blktrace.c:631 blk_trace_ioctl+0x163/0x290 kernel/trace/blktrace.c:741 blkdev_ioctl+0x111/0x770 block/ioctl.c:622 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a RIP: 0033:0x7f914d80ca89 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 1c 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f914cfc4168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f914d89c1c8 RCX: 00007f914d80ca89 RDX: 0000000020000380 RSI: 00000000c0481273 RDI: 0000000000000004 RBP: 00007f914d89c1c0 R08: 00007f914cfc46c0 R09: 0000000000000000 R10: 00007f914cfc46c0 R11: 0000000000000246 R12: 00007f914d89c1cc R13: 000000000000000b R14: 00007ffdb3560ef0 R15: 00007ffdb3560fd8 </TASK> INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.100 msecs --- This report is generated by a bot. 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