bisecting fixing commit since 3207316b3beec7e38e5dbe2f463df0cec71e0b97 building syzkaller on 79264ae39c1ef4b4875ab67d6f0c8c3e75aa6a34 testing commit 3207316b3beec7e38e5dbe2f463df0cec71e0b97 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: a5696aae228e728374dac0c462a6c3dc643155c680840a729cac53904bb6e54c all runs: crashed: INFO: task hung in vfs_setxattr testing current HEAD b172b44fcb1771e083aad806fa96f3f60e2ddfac testing commit b172b44fcb1771e083aad806fa96f3f60e2ddfac compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 01c421f84fc7ed80702b63d3e59cc27b700ea45449ce5e062c2724f6b5dffc3c all runs: crashed: INFO: task hung in vfs_setxattr revisions tested: 2, total time: 32m24.969533141s (build: 19m46.878077562s, test: 12m7.421308766s) the crash still happens on HEAD commit msg: Linux 4.19.206 crash: INFO: task hung in vfs_setxattr Bluetooth: hci1: command 0x0406 tx timeout Bluetooth: hci2: command 0x0406 tx timeout Bluetooth: hci3: command 0x0406 tx timeout Bluetooth: hci4: command 0x0406 tx timeout Bluetooth: hci5: command 0x0406 tx timeout INFO: task syz-executor.3:9856 blocked for more than 140 seconds. Not tainted 4.19.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D29528 9856 8472 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x3bb/0x780 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x53/0x90 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:748 [inline] vfs_setxattr+0xd6/0x280 fs/xattr.c:254 setxattr+0x1af/0x280 fs/xattr.c:520 __do_sys_fsetxattr fs/xattr.c:575 [inline] __se_sys_fsetxattr+0xff/0x160 fs/xattr.c:564 __x64_sys_fsetxattr+0xb9/0x140 fs/xattr.c:564 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc374763188 EFLAGS: 00000246 ORIG_RAX: 00000000000000be RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000005 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008 R13: 00007fff497d314f R14: 00007fc374763300 R15: 0000000000022000 INFO: task syz-executor.5:9920 blocked for more than 140 seconds. Not tainted 4.19.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29752 9920 8474 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x3bb/0x780 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x53/0x90 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:748 [inline] vfs_setxattr+0xd6/0x280 fs/xattr.c:254 setxattr+0x1af/0x280 fs/xattr.c:520 __do_sys_fsetxattr fs/xattr.c:575 [inline] __se_sys_fsetxattr+0xff/0x160 fs/xattr.c:564 __x64_sys_fsetxattr+0xb9/0x140 fs/xattr.c:564 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd58dcc0188 EFLAGS: 00000246 ORIG_RAX: 00000000000000be RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000005 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008 R13: 00007ffe3587d35f R14: 00007fd58dcc0300 R15: 0000000000022000 INFO: task syz-executor.1:10009 blocked for more than 140 seconds. Not tainted 4.19.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D29752 10009 8481 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x3bb/0x780 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x53/0x90 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:748 [inline] vfs_setxattr+0xd6/0x280 fs/xattr.c:254 setxattr+0x1af/0x280 fs/xattr.c:520 __do_sys_fsetxattr fs/xattr.c:575 [inline] __se_sys_fsetxattr+0xff/0x160 fs/xattr.c:564 __x64_sys_fsetxattr+0xb9/0x140 fs/xattr.c:564 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8180cc4188 EFLAGS: 00000246 ORIG_RAX: 00000000000000be RAX: ffffffffffffffa1 RBX: 000000000056c008 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000005 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008 R13: 00007fffe229238f R14: 00007f8180cc4300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1569: #0: 000000002aa80915 (rcu_read_lock){....}, at: debug_show_all_locks+0x5b/0x27a kernel/locking/lockdep.c:4443 1 lock held by in:imklog/7821: #0: 000000006f5d64c2 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xa7/0xd0 fs/file.c:767 2 locks held by syz-executor.3/9831: 1 lock held by syz-executor.5/9912: 1 lock held by syz-executor.4/9932: 1 lock held by syz-executor.2/9938: 2 locks held by syz-executor.0/9967: 1 lock held by syz-executor.1/10009: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1569 Comm: khungtaskd Not tainted 4.19.206-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x17c/0x226 lib/dump_stack.c:118 nmi_cpu_backtrace.cold.0+0x3c/0x78 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0xf6/0x120 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x5c3/0xb40 kernel/hung_task.c:287 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9967 Comm: syz-executor.0 Not tainted 4.19.206-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rcu_read_lock_held+0xa9/0xc0 kernel/rcu/update.c:288 Code: 00 5d c3 e8 a9 16 01 00 84 c0 74 09 e8 10 c0 00 00 84 c0 75 04 31 c0 5d c3 be ff ff ff ff 48 c7 c7 c0 e7 97 89 e8 e7 ae fa ff <5d> c3 e8 90 76 40 00 e9 7c ff ff ff e8 86 76 40 00 eb ac 0f 1f 40 RSP: 0018:ffff8880b354f330 EFLAGS: 00000282 RAX: 0000000000000001 RBX: 0000000000000033 RCX: ffffed1016703918 RDX: 1ffffffff13224a9 RSI: 0000000000000000 RDI: 0000000000000282 RBP: ffff8880b354f330 R08: 1ffff11016703918 R09: ffffed101744455a R10: ffffed101744455a R11: ffff8880ba222ad3 R12: ffff8880b354f450 R13: 000007b5c7000106 R14: ffff888093647410 R15: ffff8880b354f578 FS: 00007f8a5bf56700(0000) GS:ffff8880ba200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8180ce59e0 CR3: 0000000091bfd000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: radix_tree_deref_slot include/linux/radix-tree.h:241 [inline] find_get_entries+0x5cb/0x8e0 mm/filemap.c:1662 pagevec_lookup_entries+0x1d/0x60 mm/swap.c:956 truncate_inode_pages_range+0x1b4/0x1890 mm/truncate.c:328 truncate_inode_pages mm/truncate.c:475 [inline] truncate_inode_pages_final+0x6f/0xa0 mm/truncate.c:526 minix_evict_inode+0x16/0xe0 fs/minix/inode.c:29 evict+0x29c/0x590 fs/inode.c:559 dispose_list+0xfe/0x1f0 fs/inode.c:594 evict_inodes+0x2b8/0x3b0 fs/inode.c:644 generic_shutdown_super+0xac/0x330 fs/super.c:448 kill_block_super+0x96/0xe0 fs/super.c:1185 deactivate_locked_super+0x77/0xd0 fs/super.c:329 deactivate_super fs/super.c:360 [inline] deactivate_super+0x13f/0x160 fs/super.c:356 cleanup_mnt+0xa3/0x130 fs/namespace.c:1098 __cleanup_mnt+0xd/0x10 fs/namespace.c:1105 task_work_run+0x108/0x180 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xa6a/0x2d90 kernel/exit.c:870 do_group_exit+0xf8/0x2c0 kernel/exit.c:967 get_signal+0x30b/0x1970 kernel/signal.c:2589 do_signal+0x87/0x1870 arch/x86/kernel/signal.c:799 exit_to_usermode_loop+0x159/0x1e0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: Bad RIP value. RSP: 002b:00007f8a5bf56188 EFLAGS: 00000246 ORIG_RAX: 0000000000000107 RAX: 0000000000000000 RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000000200 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffd5c18098f R14: 00007f8a5bf56300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 00 5d c3 add %bl,-0x3d(%rbp) 3: e8 a9 16 01 00 callq 0x116b1 8: 84 c0 test %al,%al a: 74 09 je 0x15 c: e8 10 c0 00 00 callq 0xc021 11: 84 c0 test %al,%al 13: 75 04 jne 0x19 15: 31 c0 xor %eax,%eax 17: 5d pop %rbp 18: c3 retq 19: be ff ff ff ff mov $0xffffffff,%esi 1e: 48 c7 c7 c0 e7 97 89 mov $0xffffffff8997e7c0,%rdi 25: e8 e7 ae fa ff callq 0xfffaaf11 * 2a: 5d pop %rbp <-- trapping instruction 2b: c3 retq 2c: e8 90 76 40 00 callq 0x4076c1 31: e9 7c ff ff ff jmpq 0xffffffb2 36: e8 86 76 40 00 callq 0x4076c1 3b: eb ac jmp 0xffffffe9 3d: 0f .byte 0xf 3e: 1f (bad) 3f: 40 rex