bisecting fixing commit since 3207316b3beec7e38e5dbe2f463df0cec71e0b97 building syzkaller on 79264ae39c1ef4b4875ab67d6f0c8c3e75aa6a34 testing commit 3207316b3beec7e38e5dbe2f463df0cec71e0b97 with gcc (GCC) 8.4.1 20210217 kernel signature: 5183f121a9a5980870e173d744c90592712e56504ce14e17763523c3dfc31e67 all runs: crashed: INFO: task hung in vfs_setxattr testing current HEAD 9f84340f012ee60c12aacc03662bcdd67419a31a testing commit 9f84340f012ee60c12aacc03662bcdd67419a31a with gcc (GCC) 8.4.1 20210217 kernel signature: 21fa081bdd0a708146a5b3c334ff8f7de531a7324f452a0d9323f1a3fb180c86 all runs: crashed: INFO: task hung in vfs_setxattr revisions tested: 2, total time: 28m15.017213997s (build: 16m14.304620372s, test: 11m37.484822499s) the crash still happens on HEAD commit msg: Linux 4.19.196 crash: INFO: task hung in vfs_setxattr Bluetooth: hci0: command 0x0406 tx timeout Bluetooth: hci1: command 0x0406 tx timeout Bluetooth: hci2: command 0x0406 tx timeout Bluetooth: hci5: command 0x0406 tx timeout Bluetooth: hci4: command 0x0406 tx timeout INFO: task syz-executor.1:9896 blocked for more than 140 seconds. Not tainted 4.19.196-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D29528 9896 8467 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:00007ff943155188 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: 00007fff09ee1d2f R14: 00007ff943155300 R15: 0000000000022000 INFO: task syz-executor.5:9923 blocked for more than 140 seconds. Not tainted 4.19.196-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29752 9923 8470 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: Bad RIP value. RSP: 002b:00007fc3d452e188 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: 00007ffd625047cf R14: 00007fc3d452e300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1558: #0: 0000000061993346 (rcu_read_lock){....}, at: debug_show_all_locks+0x5b/0x27a kernel/locking/lockdep.c:4443 1 lock held by kswapd0/1967: 1 lock held by in:imklog/7795: #0: 00000000cf2581fe (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xa7/0xd0 fs/file.c:767 2 locks held by kworker/1:4/8480: #0: 00000000218bcf5e ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2124 #1: 000000006eab1dfe ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2128 3 locks held by syz-executor.1/9890: 2 locks held by syz-executor.1/9896: #0: 000000008a4ba01b (sb_writers#14){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline] #0: 000000008a4ba01b (sb_writers#14){.+.+}, at: mnt_want_write_file+0x67/0x110 fs/namespace.c:418 #1: 000000004372976c (&type->i_mutex_dir_key#9){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] #1: 000000004372976c (&type->i_mutex_dir_key#9){+.+.}, at: vfs_setxattr+0xd6/0x280 fs/xattr.c:254 1 lock held by syz-executor.4/9899: 1 lock held by syz-executor.5/9923: #0: 00000000b4aac9c2 (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #0: 00000000b4aac9c2 (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x3a0/0x8a0 kernel/rcu/tree_exp.h:667 1 lock held by syz-executor.3/9924: 3 locks held by syz-executor.2/9956: 1 lock held by syz-executor.0/9991: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1558 Comm: khungtaskd Not tainted 4.19.196-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: 9923 Comm: syz-executor.5 Not tainted 4.19.196-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:radix_tree_descend lib/radix-tree.c:133 [inline] RIP: 0010:radix_tree_next_chunk+0x156/0xa50 lib/radix-tree.c:1753 Code: 41 83 e6 3f 44 89 f3 4d 8d 64 dd 28 4c 89 e1 48 c1 e9 03 80 3c 01 00 0f 85 4a 05 00 00 49 8b 0c 24 48 89 cf 49 89 cc 83 e7 03 <48> 83 ff 01 0f 84 7a 01 00 00 45 85 c0 0f 84 66 01 00 00 49 63 ce RSP: 0018:ffff88809af2f2b8 EFLAGS: 00000202 RAX: dffffc0000000000 RBX: 0000000000000004 RCX: ffff888064041c01 RDX: 0000000000000000 RSI: ffff88809af2f3f0 RDI: 0000000000000001 RBP: ffff88809af2f330 R08: 0000000000000000 R09: 0000000000000228 R10: 0000000000000040 R11: ffff88805032eb68 R12: ffff888064041c01 R13: ffff88807c335140 R14: 0000000000000004 R15: 0000000000004cd1 FS: 00007fc3d452e700(0000) GS:ffff8880ba200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f25c5689000 CR3: 00000000a17f8000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: find_get_entries+0x572/0x8e0 mm/filemap.c:1659 pagevec_lookup_entries+0x1d/0x60 mm/swap.c:956 truncate_inode_pages_range+0x1a9/0x1920 mm/truncate.c:331 truncate_inode_pages mm/truncate.c:478 [inline] truncate_inode_pages_final+0x6f/0xa0 mm/truncate.c:529 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:00007fc3d452e188 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: 00007ffd625047cf R14: 00007fc3d452e300 R15: 0000000000022000