Hello, When using Syzkaller to fuzz the latest Linux kernel, the following crash was triggered. HEAD commit: a7904a538933 Linux 5.16-rc6 git tree: upstream console output: https://paste.ubuntu.com/p/sBNS3rSWFq/plain/ kernel config: https://paste.ubuntu.com/p/FDDNHDxtwz/plain/ Sorry, I don't have a reproducer for this crash, hope the symbolized report can help. If you fix this issue, please add the following tag to the commit: Reported-by: Yiru Xu <xyru1999@xxxxxxxxx> INFO: task syz-executor.7:13121 blocked for more than 143 seconds. Not tainted 5.16.0-rc6 #9 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.7 state:D stack:27760 pid:13121 ppid: 12530 flags:0x00000004 Call Trace: <TASK> context_switch kernel/sched/core.c:4972 [inline] __schedule+0xcd9/0x2530 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 io_schedule+0xb3/0x120 kernel/sched/core.c:8371 blk_mq_get_tag+0x58d/0xac0 block/blk-mq-tag.c:158 __blk_mq_alloc_requests+0x674/0xe00 block/blk-mq.c:486 blk_mq_alloc_request+0x116/0x210 block/blk-mq.c:520 scsi_alloc_request+0x1f/0x60 drivers/scsi/scsi_lib.c:1103 sg_start_req drivers/scsi/sg.c:1727 [inline] sg_common_write.isra.0+0x50e/0x1f30 drivers/scsi/sg.c:807 sg_write+0x7c9/0xda0 drivers/scsi/sg.c:711 vfs_write+0x22a/0xae0 fs/read_write.c:588 ksys_write+0x12d/0x250 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f90924fe89d RSP: 002b:00007f9090e6fc28 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f909261df60 RCX: 00007f90924fe89d RDX: 0000000000000030 RSI: 0000000020000040 RDI: 0000000000000004 RBP: 00007f909256b00d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff4495088f R14: 00007f909261df60 R15: 00007f9090e6fdc0 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/39: #0: ffffffff8bb80e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6764: #0: ffff888018636b70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:1034 3 locks held by syz-fuzzer/6689: #0: ffff888102adc460 (sb_writers#5){.+.+}-{0:0}, at: do_rmdir+0x1d0/0x390 fs/namei.c:4013 #1: ffff88802af421d8 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:818 [inline] #1: ffff88802af421d8 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: do_rmdir+0x21b/0x390 fs/namei.c:4017 #2: ffff888113c5b5c8 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: inode_lock include/linux/fs.h:783 [inline] #2: ffff888113c5b5c8 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: vfs_rmdir fs/namei.c:3958 [inline] #2: ffff888113c5b5c8 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: vfs_rmdir+0xe3/0x570 fs/namei.c:3946 3 locks held by kworker/u9:21/13658: #0: ffff888100ff0138 ((wq_completion)writeback){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888100ff0138 ((wq_completion)writeback){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888100ff0138 ((wq_completion)writeback){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888100ff0138 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff888100ff0138 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff888100ff0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x8c3/0x16d0 kernel/workqueue.c:2269 #1: ffffc9000f8bfdc8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x8f7/0x16d0 kernel/workqueue.c:2273 #2: ffff8881000940e0 (&type->s_umount_key#47){.+.+}-{3:3}, at: trylock_super+0x1d/0x100 fs/super.c:418 4 locks held by kworker/2:10/30001: #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x8c3/0x16d0 kernel/workqueue.c:2269 #1: ffffc9001352fdc8 ((work_completion)(&ap->scsi_rescan_task)){+.+.}-{0:0}, at: process_one_work+0x8f7/0x16d0 kernel/workqueue.c:2273 #2: ffff8881075ac2a0 (&ap->scsi_scan_mutex){+.+.}-{3:3}, at: ata_scsi_dev_rescan+0x38/0x230 drivers/ata/libata-scsi.c:4646 #3: ffff888107c9a3e0 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #3: ffff888107c9a3e0 (&dev->mutex){....}-{3:3}, at: scsi_rescan_device+0x28/0x210 drivers/scsi/scsi_scan.c:1555 ============================================= NMI backtrace for cpu 2 CPU: 2 PID: 39 Comm: khungtaskd Not tainted 5.16.0-rc6 #9 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1a1/0x1e0 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+0xcc8/0x1010 kernel/hung_task.c:295 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> Sending NMI from CPU 2 to CPUs 0-1,3: NMI backtrace for cpu 0 CPU: 0 PID: 11470 Comm: kworker/u8:5 Not tainted 5.16.0-rc6 #9 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: bat_events batadv_nc_worker RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:91 [inline] RIP: 0010:lock_acquire kernel/locking/lockdep.c:5613 [inline] RIP: 0010:lock_acquire+0x13b/0x520 kernel/locking/lockdep.c:5602 Code: 85 c5 01 00 00 65 48 8b 14 25 40 70 02 00 48 8d ba 1c 0a 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 0f b6 0c 01 <48> 89 f8 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85 80 03 00 00 8b RSP: 0018:ffffc9000fc7fbf0 EFLAGS: 00000213 RAX: dffffc0000000000 RBX: 1ffff92001f8ff80 RCX: 0000000000000000 RDX: ffff888054573980 RSI: 0000000000000001 RDI: ffff88805457439c RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff1b20a2b R10: ffffffff8d905157 R11: fffffbfff1b20a2a R12: 0000000000000002 R13: ffffffff8bb80e20 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888063e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563740b0c900 CR3: 000000000b88e000 CR4: 0000000000350ef0 Call Trace: <TASK> rcu_lock_acquire include/linux/rcupdate.h:268 [inline] 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+0x114/0x770 net/batman-adv/network-coding.c:723 process_one_work+0x9df/0x16d0 kernel/workqueue.c:2298 worker_thread+0x90/0xed0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:733 NMI backtrace for cpu 3 CPU: 3 PID: 3047 Comm: systemd-journal Not tainted 5.16.0-rc6 #9 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:get_reg+0xef/0x170 arch/x86/kernel/unwind_orc.c:405 Code: 11 00 0f 85 8d 00 00 00 49 89 45 00 41 bc 01 00 00 00 48 83 c4 08 5b 44 89 e0 5d 41 5c 41 5d c3 48 8d 7c f5 00 e8 01 fc ff ff <4c> 89 e9 48 ba 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 11 00 75 RSP: 0018:ffffc9000128f928 EFLAGS: 00000202 RAX: 00007ffd54a44fe0 RBX: ffffc9000128fa50 RCX: 1ffff92000251f54 RDX: 0000000000000006 RSI: 0000000000000004 RDI: ffffc9000128ff78 RBP: ffffc9000128ff58 R08: ffffffff8ea3f366 R09: ffffffff8ea3f360 R10: ffffc9000128faaf R11: 0000000000088089 R12: 0000000000000001 R13: ffffc9000128f9d8 R14: ffffc9000128fa50 R15: ffffc9000128ff58 FS: 00007fbeac5ba8c0(0000) GS:ffff888135d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbea9dca000 CR3: 000000001b63f000 CR4: 0000000000350ee0 Call Trace: <TASK> unwind_next_frame+0xfe8/0x1780 arch/x86/kernel/unwind_orc.c:595 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522 kasan_kmalloc include/linux/kasan.h:269 [inline] __kmalloc+0x1d2/0x3d0 mm/slub.c:4423 kmalloc include/linux/slab.h:595 [inline] kzalloc include/linux/slab.h:724 [inline] lsm_cred_alloc security/security.c:537 [inline] security_prepare_creds+0x10e/0x190 security/security.c:1692 prepare_creds+0x56e/0x7b0 kernel/cred.c:291 access_override_creds fs/open.c:351 [inline] do_faccessat+0x3f4/0x850 fs/open.c:415 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fbeab8769c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd54a44fa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffd54a47ec0 RCX: 00007fbeab8769c7 RDX: 00007fbeac2e7a00 RSI: 0000000000000000 RDI: 000055b9fe0f89a3 RBP: 00007ffd54a44fe0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffd54a47ec0 R15: 00007ffd54a454d0 </TASK> ---------------- Code disassembly (best guess): 0: 85 c5 test %eax,%ebp 2: 01 00 add %eax,(%rax) 4: 00 65 48 add %ah,0x48(%rbp) 7: 8b 14 25 40 70 02 00 mov 0x27040,%edx e: 48 8d ba 1c 0a 00 00 lea 0xa1c(%rdx),%rdi 15: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1c: fc ff df 1f: 48 89 f9 mov %rdi,%rcx 22: 48 c1 e9 03 shr $0x3,%rcx 26: 0f b6 0c 01 movzbl (%rcx,%rax,1),%ecx * 2a: 48 89 f8 mov %rdi,%rax <-- trapping instruction 2d: 83 e0 07 and $0x7,%eax 30: 83 c0 03 add $0x3,%eax 33: 38 c8 cmp %cl,%al 35: 7c 08 jl 0x3f 37: 84 c9 test %cl,%cl 39: 0f 85 80 03 00 00 jne 0x3bf 3f: 8b .byte 0x8b Best Regards, Yiru
