INFO: task syz-executor0:8257 blocked for more than 140 seconds. Not tainted 4.20.0-rc3+ #124 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D18584 8257 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:280 [inline] rwsem_down_read_failed+0x371/0x710 kernel/locking/rwsem-xadd.c:297 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0x9b/0x120 kernel/locking/rwsem.c:26 inode_lock_shared include/linux/fs.h:767 [inline] lookup_slow+0x49/0x80 fs/namei.c:1687 walk_component+0x92b/0x2590 fs/namei.c:1810 link_path_walk.part.40+0xa61/0x1530 fs/namei.c:2141 link_path_walk fs/namei.c:2072 [inline] path_openat+0x270/0x5150 fs/namei.c:3533 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_open fs/open.c:1081 [inline] __se_sys_open fs/open.c:1076 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1076 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455570 Code: Bad RIP value. RSP: 002b:00007ffc816b5180 EFLAGS: 00000202 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455570 RDX: 0000000000000000 RSI: 0000000000090800 RDI: 00000000004bc2ae RBP: 00000000000002ba R08: 0000000000000001 R09: 0000000002891940 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 R13: 0000000000048b7f R14: 0000000000000097 R15: 0000000000000000 INFO: task syz-executor0:12466 blocked for more than 140 seconds. Not tainted 4.20.0-rc3+ #124 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D24632 12466 8257 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 __rwsem_down_write_failed_common+0xc9a/0x15e0 kernel/locking/rwsem-xadd.c:577 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:606 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+0xa5/0x130 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:757 [inline] do_last fs/namei.c:3321 [inline] path_openat+0x15c4/0x5150 fs/namei.c:3534 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: Bad RIP value. RSP: 002b:00007f838d191c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457569 RDX: 0000000000002761 RSI: 0000000020000240 RDI: ffffffffffffffff RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f838d1926d4 R13: 00000000004c2e43 R14: 00000000004d4db0 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1019: #0: 0000000013b49f40 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5946: #0: 00000000befd45b4 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/6036: #0: 00000000d9150d65 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000034762372 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6037: #0: 00000000e6e912c0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000000cb36b38 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6038: #0: 0000000092cd05c7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a805120c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6039: #0: 000000000b4b19bc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000ca1a65c8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6040: #0: 00000000b727f85b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000023f718ed (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6041: #0: 0000000094ec1c1b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000003d9505c4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6042: #0: 000000008f4db569 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000440b1166 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 1 lock held by syz-executor0/8257: #0: 000000008594f44b (&sb->s_type->i_mutex_key#19){++++}, at: inode_lock_shared include/linux/fs.h:767 [inline] #0: 000000008594f44b (&sb->s_type->i_mutex_key#19){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 3 locks held by syz-executor0/12443: 2 locks held by syz-executor0/12466: #0: 00000000482a28fe (sb_writers#12){.+.+}, at: sb_start_write include/linux/fs.h:1597 [inline] #0: 00000000482a28fe (sb_writers#12){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 000000008594f44b (&sb->s_type->i_mutex_key#19){++++}, at: inode_lock include/linux/fs.h:757 [inline] #1: 000000008594f44b (&sb->s_type->i_mutex_key#19){++++}, at: do_last fs/namei.c:3321 [inline] #1: 000000008594f44b (&sb->s_type->i_mutex_key#19){++++}, at: path_openat+0x15c4/0x5150 fs/namei.c:3534 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1019 Comm: khungtaskd Not tainted 4.20.0-rc3+ #124 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+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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:205 [inline] watchdog+0xb51/0x1060 kernel/hung_task.c:289 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.413 msecs NMI backtrace for cpu 1 CPU: 1 PID: 12443 Comm: syz-executor0 Not tainted 4.20.0-rc3+ #124 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x20/0x50 kernel/kcov.c:101 Code: 4c d8 20 4c 89 08 5d c3 66 90 55 48 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 c8 62 82 7e 81 e2 00 01 1f 00 75 2b <8b> 90 d8 12 00 00 83 fa 02 75 20 48 8b 88 e0 12 00 00 8b 80 dc 12 RSP: 0018:ffff888187a56c68 EFLAGS: 00000046 RAX: ffff888191b10340 RBX: ffff8881bf8135e8 RCX: ffffffff81e05fd5 RDX: 0000000000000000 RSI: ffffffff81e05fe4 RDI: 0000000000000005 RBP: ffff888187a56c68 R08: ffff888191b10340 R09: fffff94000d3f95e R10: fffff94000d3f95e R11: ffffea00069fcaf7 R12: 000000000000000c R13: dffffc0000000000 R14: 000000000000000b R15: 0000000000000447 FS: 00007f838d1d4700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42dd05000 CR3: 00000001bf7be000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lookup_bh_lru fs/buffer.c:1261 [inline] __find_get_block+0x174/0xf20 fs/buffer.c:1290 __getblk_slow fs/buffer.c:1039 [inline] __getblk_gfp+0x2b3/0xd50 fs/buffer.c:1320 __bread_gfp+0x2d/0x310 fs/buffer.c:1354 sb_bread include/linux/buffer_head.h:307 [inline] fat__get_entry+0x5a6/0xa40 fs/fat/dir.c:101 fat_get_entry fs/fat/dir.c:129 [inline] fat_search_long+0x33b/0x1570 fs/fat/dir.c:479 vfat_find+0x16d/0x1a0 fs/fat/namei_vfat.c:697 vfat_lookup+0x107/0x640 fs/fat/namei_vfat.c:711 lookup_open+0x72e/0x1b90 fs/namei.c:3213 do_last fs/namei.c:3324 [inline] path_openat+0x15e4/0x5150 fs/namei.c:3534 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f838d1d3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457569 RDX: 0000000000002761 RSI: 0000000020000240 RDI: ffffffffffffffff RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f838d1d46d4 R13: 00000000004c2e43 R14: 00000000004d4db0 R15: 00000000ffffffff