INFO: task hung in vfs_setxattr

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: e7d2672c Linux 4.19.71
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=153f3ab9600000
kernel config: https://syzkaller.appspot.com/x/.config?x=47881f21d9108add
dashboard link: https://syzkaller.appspot.com/bug?extid=3ebdc5eaa4459865af7a
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3ebdc5...@syzkaller.appspotmail.com

netlink: 8 bytes leftover after parsing attributes in process
`syz-executor.3'.
netlink: 'syz-executor.3': attribute type 21 has an invalid length.
netlink: 8 bytes leftover after parsing attributes in process
`syz-executor.3'.
INFO: task syz-executor.1:11785 blocked for more than 140 seconds.
Not tainted 4.19.71 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1 D29880 11785 7546 0x10000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
__rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
rwsem_down_write_failed+0x774/0xc30 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:747 [inline]
vfs_setxattr+0x98/0x100 fs/xattr.c:218
setxattr+0x26f/0x380 fs/xattr.c:450
path_setxattr+0x197/0x1b0 fs/xattr.c:469
__do_sys_lsetxattr fs/xattr.c:491 [inline]
__se_sys_lsetxattr fs/xattr.c:487 [inline]
__x64_sys_lsetxattr+0xc1/0x150 fs/xattr.c:487
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4598e9
Code: Bad RIP value.
RSP: 002b:00007fa78e4e7c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000004598e9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000020000080
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa78e4e86d4
R13: 00000000004ce768 R14: 00000000004da6e0 R15: 00000000ffffffff
INFO: task syz-executor.1:11816 blocked for more than 140 seconds.
Not tainted 4.19.71 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1 D27944 11816 7546 0x10000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
__rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
rwsem_down_write_failed+0x774/0xc30 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:747 [inline]
lock_mount+0x8c/0x2e0 fs/namespace.c:2039
do_add_mount+0x27/0x380 fs/namespace.c:2416
do_new_mount fs/namespace.c:2483 [inline]
do_mount+0x160a/0x2bc0 fs/namespace.c:2799
ksys_mount+0xdb/0x150 fs/namespace.c:3015
__do_sys_mount fs/namespace.c:3029 [inline]
__se_sys_mount fs/namespace.c:3026 [inline]
__x64_sys_mount+0xbe/0x150 fs/namespace.c:3026
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4598e9
Code: Bad RIP value.
RSP: 002b:00007fa78e4c6c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000004598e9
RDX: 0000000020000180 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 000000000075c070 R08: 00000000200001c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa78e4c76d4
R13: 00000000004c5e68 R14: 00000000004da9b0 R15: 00000000ffffffff
INFO: task syz-executor.1:11817 blocked for more than 140 seconds.
Not tainted 4.19.71 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1 D29464 11817 7546 0x10000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
__rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
rwsem_down_write_failed+0x774/0xc30 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:747 [inline]
chown_common+0x320/0x5c0 fs/open.c:648
do_fchownat+0x143/0x200 fs/open.c:681
__do_sys_chown fs/open.c:701 [inline]
__se_sys_chown fs/open.c:699 [inline]
__x64_sys_chown+0x7b/0xc0 fs/open.c:699
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4598e9
Code: Bad RIP value.
RSP: 002b:00007fa78e4a5c78 EFLAGS: 00000246 ORIG_RAX: 000000000000005c
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598e9
RDX: 0000000000000000 RSI: 0000000000000cff RDI: 00000000200001c0
RBP: 000000000075c118 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa78e4a66d4
R13: 00000000004c5ab1 R14: 00000000004d1ad0 R15: 00000000ffffffff
INFO: task syz-executor.1:11818 blocked for more than 140 seconds.
Not tainted 4.19.71 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1 D29656 11818 7546 0x10000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
__rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
rwsem_down_write_failed+0x774/0xc30 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:747 [inline]
chown_common+0x320/0x5c0 fs/open.c:648
do_fchownat+0x143/0x200 fs/open.c:681
__do_sys_chown fs/open.c:701 [inline]
__se_sys_chown fs/open.c:699 [inline]
__x64_sys_chown+0x7b/0xc0 fs/open.c:699
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4598e9
Code: Bad RIP value.
RSP: 002b:00007fa78e484c78 EFLAGS: 00000246 ORIG_RAX: 000000000000005c
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598e9
RDX: 0000000000000000 RSI: 0000000000000cff RDI: 00000000200001c0
RBP: 000000000075c1c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa78e4856d4
R13: 00000000004c5ab1 R14: 00000000004d1ad0 R15: 00000000ffffffff
INFO: task syz-executor.1:11819 blocked for more than 140 seconds.
Not tainted 4.19.71 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1 D29160 11819 7546 0x10000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
__rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
rwsem_down_write_failed+0x774/0xc30 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:747 [inline]
utimes_common.isra.0+0x2e8/0x600 fs/utimes.c:90
do_utimes+0x1f5/0x350 fs/utimes.c:156
do_futimesat+0x147/0x1c0 fs/utimes.c:212
__do_sys_utimes fs/utimes.c:225 [inline]
__se_sys_utimes fs/utimes.c:222 [inline]
__x64_sys_utimes+0x59/0x80 fs/utimes.c:222
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4598e9
Code: Bad RIP value.
RSP: 002b:00007fa78e463c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000eb
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00000000004598e9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000200
RBP: 000000000075c268 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa78e4646d4
R13: 00000000004c90c1 R14: 00000000004e0320 R15: 00000000ffffffff

Showing all locks held in the system:
1 lock held by khungtaskd/1037:
#0: 0000000036f2e6d3 (rcu_read_lock){....}, at:
debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4435
1 lock held by rsyslogd/7379:
2 locks held by getty/7502:
#0: 000000008548b212 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000001c0e07e4 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7503:
#0: 0000000037b96870 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000000cc4b701 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7504:
#0: 000000005d39d0fe (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 0000000005d1223a (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7505:
#0: 0000000032110b4b (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000ca2497cc (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7506:
#0: 00000000566fc737 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000d57f9fab (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7507:
#0: 00000000a15ee11e (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000cb25d8e4 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7508:
#0: 00000000204491bb (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000cbb9173f (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by syz-executor.1/11782:
#0: 00000000f2e4d7cf (sb_writers#22){.+.+}, at: sb_start_write
include/linux/fs.h:1578 [inline]
#0: 00000000f2e4d7cf (sb_writers#22){.+.+}, at: mnt_want_write+0x3f/0xc0
fs/namespace.c:360
#1: 00000000bae856f1 (&sb->s_type->i_mutex_key#29){+.+.}, at: inode_lock
include/linux/fs.h:747 [inline]
#1: 00000000bae856f1 (&sb->s_type->i_mutex_key#29){+.+.}, at:
utimes_common.isra.0+0x2e8/0x600 fs/utimes.c:90
2 locks held by syz-executor.1/11785:
#0: 00000000f2e4d7cf (sb_writers#22){.+.+}, at: sb_start_write
include/linux/fs.h:1578 [inline]
#0: 00000000f2e4d7cf (sb_writers#22){.+.+}, at: mnt_want_write+0x3f/0xc0
fs/namespace.c:360
#1: 00000000bae856f1 (&sb->s_type->i_mutex_key#29){+.+.}, at: inode_lock
include/linux/fs.h:747 [inline]
#1: 00000000bae856f1 (&sb->s_type->i_mutex_key#29){+.+.}, at:
vfs_setxattr+0x98/0x100 fs/xattr.c:218
1 lock held by syz-executor.1/11816:
#0: 00000000bae856f1 (&sb->s_type->i_mutex_key#29){+.+.}, at: inode_lock
include/linux/fs.h:747 [inline]
#0: 00000000bae856f1 (&sb->s_type->i_mutex_key#29){+.+.}, at:
lock_mount+0x8c/0x2e0 fs/namespace.c:2039
2 locks held by syz-executor.1/11817:
#0: 00000000f2e4d7cf (sb_writers#22){.+.+}, at: sb_start_write
include/linux/fs.h:1578 [inline]
#0: 00000000f2e4d7cf (sb_writers#22){.+.+}, at: mnt_want_write+0x3f/0xc0
fs/namespace.c:360
#1: 00000000bae856f1 (&sb->s_type->i_mutex_key#29){+.+.}, at: inode_lock
include/linux/fs.h:747 [inline]
#1: 00000000bae856f1 (&sb->s_type->i_mutex_key#29){+.+.}, at:
chown_common+0x320/0x5c0 fs/open.c:648
2 locks held by syz-executor.1/11818:
#0: 00000000f2e4d7cf (sb_writers#22){.+.+}, at: sb_start_write
include/linux/fs.h:1578 [inline]
#0: 00000000f2e4d7cf (sb_writers#22){.+.+}, at: mnt_want_write+0x3f/0xc0
fs/namespace.c:360
#1: 00000000bae856f1 (&sb->s_type->i_mutex_key#29){+.+.}, at: inode_lock
include/linux/fs.h:747 [inline]
#1: 00000000bae856f1 (&sb->s_type->i_mutex_key#29){+.+.}, at:
chown_common+0x320/0x5c0 fs/open.c:648
2 locks held by syz-executor.1/11819:
#0: 00000000f2e4d7cf (sb_writers#22){.+.+}, at: sb_start_write
include/linux/fs.h:1578 [inline]
#0: 00000000f2e4d7cf (sb_writers#22){.+.+}, at: mnt_want_write+0x3f/0xc0
fs/namespace.c:360
#1: 00000000bae856f1 (&sb->s_type->i_mutex_key#29){+.+.}, at: inode_lock
include/linux/fs.h:747 [inline]
#1: 00000000bae856f1 (&sb->s_type->i_mutex_key#29){+.+.}, at:
utimes_common.isra.0+0x2e8/0x600 fs/utimes.c:90

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 1037 Comm: khungtaskd Not tainted 4.19.71 #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+0x172/0x1f0 lib/dump_stack.c:113
nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 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+0x9df/0xee0 kernel/hung_task.c:287
kthread+0x354/0x420 kernel/kthread.c:246
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10
arch/x86/include/asm/irqflags.h:60


---
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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.