INFO: task hung in fuse_launder_page

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syzbot

unread,
May 3, 2021, 5:31:16 AM5/3/21
to syzkaller...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: 7d7d1c0a Linux 4.14.232
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11a55385d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=17ee8a0e183900d8
dashboard link: https://syzkaller.appspot.com/bug?extid=870bb7df35785306a4b3

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+870bb7...@syzkaller.appspotmail.com

Bluetooth: hci2 command 0x0406 tx timeout
Bluetooth: hci3 command 0x0406 tx timeout
Bluetooth: hci1 command 0x0406 tx timeout
Bluetooth: hci5 command 0x0406 tx timeout
Bluetooth: hci4 command 0x0406 tx timeout
INFO: task syz-executor.3:10904 blocked for more than 140 seconds.
Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3 D28384 10904 7994 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2808 [inline]
__schedule+0x88b/0x1de0 kernel/sched/core.c:3384
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
fuse_wait_on_page_writeback fs/fuse/file.c:382 [inline]
fuse_wait_on_page_writeback.isra.0+0xdc/0x120 fs/fuse/file.c:378
fuse_launder_page fs/fuse/file.c:2032 [inline]
fuse_launder_page+0xa2/0xd0 fs/fuse/file.c:2025
do_launder_page mm/truncate.c:609 [inline]
invalidate_inode_pages2_range+0x547/0xc00 mm/truncate.c:685
fuse_finish_open+0x262/0x500 fs/fuse/file.c:181
fuse_open_common+0x1fc/0x250 fs/fuse/file.c:221
do_dentry_open+0x44b/0xec0 fs/open.c:777
vfs_open+0x105/0x220 fs/open.c:888
do_last fs/namei.c:3428 [inline]
path_openat+0x628/0x2970 fs/namei.c:3569
do_filp_open+0x179/0x3c0 fs/namei.c:3603
do_sys_open+0x296/0x410 fs/open.c:1081
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x4665f9
RSP: 002b:00007f76d2b59188 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180
RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffdb2364a9f R14: 00007f76d2b59300 R15: 0000000000022000
INFO: task syz-executor.3:10920 blocked for more than 140 seconds.
Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3 D29168 10920 7994 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2808 [inline]
__schedule+0x88b/0x1de0 kernel/sched/core.c:3384
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
__rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline]
rwsem_down_write_failed+0x343/0x6d0 kernel/locking/rwsem-xadd.c:617
call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105
__down_write arch/x86/include/asm/rwsem.h:126 [inline]
down_write+0x4f/0x90 kernel/locking/rwsem.c:56
inode_lock include/linux/fs.h:719 [inline]
fuse_open_common+0x177/0x250 fs/fuse/file.c:214
do_dentry_open+0x44b/0xec0 fs/open.c:777
vfs_open+0x105/0x220 fs/open.c:888
do_last fs/namei.c:3428 [inline]
path_openat+0x628/0x2970 fs/namei.c:3569
do_filp_open+0x179/0x3c0 fs/namei.c:3603
do_sys_open+0x296/0x410 fs/open.c:1081
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x4665f9
RSP: 002b:00007f76d2b38188 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 00000000004665f9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000000
RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 00007ffdb2364a9f R14: 00007f76d2b38300 R15: 0000000000022000
INFO: task syz-executor.3:10924 blocked for more than 140 seconds.
Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3 D29696 10924 7994 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2808 [inline]
__schedule+0x88b/0x1de0 kernel/sched/core.c:3384
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
__rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline]
rwsem_down_write_failed+0x343/0x6d0 kernel/locking/rwsem-xadd.c:617
call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105
__down_write arch/x86/include/asm/rwsem.h:126 [inline]
down_write+0x4f/0x90 kernel/locking/rwsem.c:56
inode_lock include/linux/fs.h:719 [inline]
fuse_flush+0x1a1/0x4e0 fs/fuse/file.c:420
filp_close+0x9d/0x140 fs/open.c:1158
do_dup2+0x1ec/0x3d0 fs/file.c:846
SYSC_dup3 fs/file.c:902 [inline]
SyS_dup3+0x218/0x360 fs/file.c:877
SYSC_dup2 fs/file.c:923 [inline]
SyS_dup2+0x25/0x300 fs/file.c:911
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x4665f9
RSP: 002b:00007f76d2b17188 EFLAGS: 00000246 ORIG_RAX: 0000000000000021
RAX: ffffffffffffffda RBX: 000000000056c0b0 RCX: 00000000004665f9
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000003
RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0b0
R13: 00007ffdb2364a9f R14: 00007f76d2b17300 R15: 0000000000022000
INFO: task syz-executor.3:10927 blocked for more than 140 seconds.
Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3 D28104 10927 7994 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2808 [inline]
__schedule+0x88b/0x1de0 kernel/sched/core.c:3384
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
__rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline]
rwsem_down_write_failed+0x343/0x6d0 kernel/locking/rwsem-xadd.c:617
call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105
__down_write arch/x86/include/asm/rwsem.h:126 [inline]
down_write+0x4f/0x90 kernel/locking/rwsem.c:56
inode_lock include/linux/fs.h:719 [inline]
lock_mount+0xbb/0x450 fs/namespace.c:2119
do_add_mount+0x63/0x4f0 fs/namespace.c:2496
do_new_mount fs/namespace.c:2563 [inline]
do_mount+0x157f/0x2a00 fs/namespace.c:2879
SYSC_mount fs/namespace.c:3095 [inline]
SyS_mount+0xa8/0x120 fs/namespace.c:3072
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x4665f9
RSP: 002b:00007f76d2af6188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 000000000056c158 RCX: 00000000004665f9
RDX: 0000000020002100 RSI: 00000000200020c0 RDI: 0000000000000000
RBP: 00000000004bfce1 R08: 0000000020002140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c158
R13: 00007ffdb2364a9f R14: 00007f76d2af6300 R15: 0000000000022000

Showing all locks held in the system:
1 lock held by khungtaskd/1533:
#0: (tasklist_lock){.+.+}, at: [<ffffffff8700b7b7>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548
1 lock held by in:imklog/7683:
#0: (&f->f_pos_lock){+.+.}, at: [<ffffffff818d39ab>] __fdget_pos+0x1fb/0x2b0 fs/file.c:769
2 locks held by syz-executor.3/10904:
#0: (sb_writers#18){.+.+}, at: [<ffffffff818dc80a>] sb_start_write include/linux/fs.h:1549 [inline]
#0: (sb_writers#18){.+.+}, at: [<ffffffff818dc80a>] mnt_want_write+0x3a/0xb0 fs/namespace.c:386
#1: (&sb->s_type->i_mutex_key#25){+.+.}, at: [<ffffffff822ed7d7>] inode_lock include/linux/fs.h:719 [inline]
#1: (&sb->s_type->i_mutex_key#25){+.+.}, at: [<ffffffff822ed7d7>] fuse_open_common+0x177/0x250 fs/fuse/file.c:214
2 locks held by syz-executor.3/10920:
#0: (sb_writers#18){.+.+}, at: [<ffffffff818dc80a>] sb_start_write include/linux/fs.h:1549 [inline]
#0: (sb_writers#18){.+.+}, at: [<ffffffff818dc80a>] mnt_want_write+0x3a/0xb0 fs/namespace.c:386
#1: (&sb->s_type->i_mutex_key#25){+.+.}, at: [<ffffffff822ed7d7>] inode_lock include/linux/fs.h:719 [inline]
#1: (&sb->s_type->i_mutex_key#25){+.+.}, at: [<ffffffff822ed7d7>] fuse_open_common+0x177/0x250 fs/fuse/file.c:214
1 lock held by syz-executor.3/10924:
#0: (&sb->s_type->i_mutex_key#25){+.+.}, at: [<ffffffff822edb91>] inode_lock include/linux/fs.h:719 [inline]
#0: (&sb->s_type->i_mutex_key#25){+.+.}, at: [<ffffffff822edb91>] fuse_flush+0x1a1/0x4e0 fs/fuse/file.c:420
1 lock held by syz-executor.3/10927:
#0: (&sb->s_type->i_mutex_key#25){+.+.}, at: [<ffffffff818de13b>] inode_lock include/linux/fs.h:719 [inline]
#0: (&sb->s_type->i_mutex_key#25){+.+.}, at: [<ffffffff818de13b>] lock_mount+0xbb/0x450 fs/namespace.c:2119

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

NMI backtrace for cpu 0
CPU: 0 PID: 1533 Comm: khungtaskd Not tainted 4.14.232-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x1b2/0x281 lib/dump_stack.c:58
nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
watchdog+0x5b9/0xb40 kernel/hung_task.c:274
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4615 Comm: systemd-journal Not tainted 4.14.232-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a19dc600 task.stack: ffff8880a19e0000
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:66
RSP: 0018:ffff8880a19e7d10 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000010
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffff8880b4b7fa40
RBP: 0000000000000000 R08: 0000000000001000 R09: ffff8880b4b7fa40
R10: 0000000000000000 R11: ffff8880a19dc600 R12: ffffea0002d2df80
R13: ffff8880b4b7ea40 R14: ffff88823f8bb200 R15: ffff88823f8bb200
FS: 00007f84c86c38c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f84c5afb000 CR3: 00000000a1884000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 000000000000d0eb
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
cache_init_objs mm/slab.c:2577 [inline]
cache_grow_begin+0x4d4/0x700 mm/slab.c:2703
cache_alloc_refill+0x273/0x350 mm/slab.c:3043
____cache_alloc mm/slab.c:3125 [inline]
__do_cache_alloc mm/slab.c:3347 [inline]
slab_alloc mm/slab.c:3382 [inline]
kmem_cache_alloc+0x333/0x3c0 mm/slab.c:3550
getname_flags+0xc8/0x550 fs/namei.c:138
do_sys_open+0x1ce/0x410 fs/open.c:1075
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f84c7c52840
RSP: 002b:00007ffc75af8a18 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007ffc75af8d20 RCX: 00007f84c7c52840
RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 0000559df52f6800
RBP: 000000000000000d R08: 000000000000c0c1 R09: 00000000ffffffff
R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000559df52e9040 R14: 00007ffc75af8ce0 R15: 0000559df52f68f0
Code: 48 c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

syzbot

unread,
May 9, 2021, 8:49:23 AM5/9/21
to syzkaller...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: 3c8c2309 Linux 4.19.190
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=135d7579d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=d3c2572d41264a3d
dashboard link: https://syzkaller.appspot.com/bug?extid=3dc515e331d418e1de42

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3dc515...@syzkaller.appspotmail.com

wlan1: No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)
ieee802154 phy0 wpan0: encryption failed: -22
ieee802154 phy1 wpan1: encryption failed: -22
wlan1: No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)
INFO: task syz-executor.5:17327 blocked for more than 140 seconds.
Not tainted 4.19.190-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5 D27792 17327 12884 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
fuse_wait_on_page_writeback fs/fuse/file.c:383 [inline]
fuse_wait_on_page_writeback.isra.0+0x11b/0x170 fs/fuse/file.c:379
fuse_launder_page fs/fuse/file.c:2033 [inline]
fuse_launder_page+0xb6/0xe0 fs/fuse/file.c:2026
do_launder_page mm/truncate.c:658 [inline]
invalidate_inode_pages2_range+0x786/0x10f0 mm/truncate.c:730
fuse_finish_open+0x2e2/0x590 fs/fuse/file.c:182
fuse_open_common+0x254/0x2c0 fs/fuse/file.c:222
do_dentry_open+0x4aa/0x1160 fs/open.c:796
do_last fs/namei.c:3421 [inline]
path_openat+0x793/0x2df0 fs/namei.c:3537
do_filp_open+0x18c/0x3f0 fs/namei.c:3567
do_sys_open+0x3b3/0x520 fs/open.c:1085
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4665f9
Code: Bad RIP value.
RSP: 002b:00007fc5d9434188 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9
RDX: 0000000000000000 RSI: 0000000000080380 RDI: 0000000020000100
RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffc7ac4859f R14: 00007fc5d9434300 R15: 0000000000022000
INFO: task syz-executor.5:17337 blocked for more than 140 seconds.
Not tainted 4.19.190-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5 D29464 17337 12884 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
__rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
rwsem_down_write_failed+0x3aa/0x760 kernel/locking/rwsem-xadd.c:618
call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:117
__down_write arch/x86/include/asm/rwsem.h:142 [inline]
down_write+0x4f/0x90 kernel/locking/rwsem.c:72
inode_lock include/linux/fs.h:748 [inline]
fuse_open_common+0x1bc/0x2c0 fs/fuse/file.c:215
do_dentry_open+0x4aa/0x1160 fs/open.c:796
do_last fs/namei.c:3421 [inline]
path_openat+0x793/0x2df0 fs/namei.c:3537
do_filp_open+0x18c/0x3f0 fs/namei.c:3567
do_sys_open+0x3b3/0x520 fs/open.c:1085
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4665f9
Code: Bad RIP value.
RSP: 002b:00007fc5d9413188 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 00000000004665f9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000000
RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 00007ffc7ac4859f R14: 00007fc5d9413300 R15: 0000000000022000
INFO: task syz-executor.5:17345 blocked for more than 140 seconds.
Not tainted 4.19.190-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5 D29464 17345 12884 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
__rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
rwsem_down_write_failed+0x3aa/0x760 kernel/locking/rwsem-xadd.c:618
call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:117
__down_write arch/x86/include/asm/rwsem.h:142 [inline]
down_write+0x4f/0x90 kernel/locking/rwsem.c:72
inode_lock include/linux/fs.h:748 [inline]
fuse_flush+0x1fd/0x5b0 fs/fuse/file.c:421
filp_close+0xb4/0x160 fs/open.c:1162
do_dup2+0x233/0x450 fs/file.c:844
ksys_dup3+0x269/0x3c0 fs/file.c:900
__do_sys_dup2 fs/file.c:926 [inline]
__se_sys_dup2+0x2e/0x390 fs/file.c:914
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4665f9
Code: Bad RIP value.
RSP: 002b:00007fc5d93f2188 EFLAGS: 00000246 ORIG_RAX: 0000000000000021
RAX: ffffffffffffffda RBX: 000000000056c0b0 RCX: 00000000004665f9
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000003
RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0b0
R13: 00007ffc7ac4859f R14: 00007fc5d93f2300 R15: 0000000000022000
INFO: task syz-executor.5:17404 blocked for more than 140 seconds.
Not tainted 4.19.190-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5 D27808 17404 12884 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
__rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
rwsem_down_write_failed+0x3aa/0x760 kernel/locking/rwsem-xadd.c:618
call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:117
__down_write arch/x86/include/asm/rwsem.h:142 [inline]
down_write+0x4f/0x90 kernel/locking/rwsem.c:72
inode_lock include/linux/fs.h:748 [inline]
lock_mount+0xcc/0x4a0 fs/namespace.c:2039
do_add_mount+0x73/0x560 fs/namespace.c:2416
do_new_mount fs/namespace.c:2483 [inline]
do_mount+0x1956/0x2f10 fs/namespace.c:2799
ksys_mount+0xcf/0x130 fs/namespace.c:3015
__do_sys_mount fs/namespace.c:3029 [inline]
__se_sys_mount fs/namespace.c:3026 [inline]
__x64_sys_mount+0xba/0x150 fs/namespace.c:3026
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4665f9
Code: Bad RIP value.
RSP: 002b:00007fc5d93b0188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 000000000056c200 RCX: 00000000004665f9
RDX: 0000000020002100 RSI: 00000000200020c0 RDI: 0000000000000000
RBP: 00000000004bfce1 R08: 0000000020002140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c200
R13: 00007ffc7ac4859f R14: 00007fc5d93b0300 R15: 0000000000022000

Showing all locks held in the system:
1 lock held by khungtaskd/1569:
#0: 000000003563befc (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441
1 lock held by in:imklog/7782:
2 locks held by syz-executor.5/17327:
#0: 000000005ce4e181 (sb_writers#20){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline]
#0: 000000005ce4e181 (sb_writers#20){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360
#1: 0000000038be02d6 (&sb->s_type->i_mutex_key#27){+.+.}, at: inode_lock include/linux/fs.h:748 [inline]
#1: 0000000038be02d6 (&sb->s_type->i_mutex_key#27){+.+.}, at: fuse_open_common+0x1bc/0x2c0 fs/fuse/file.c:215
2 locks held by syz-executor.5/17337:
#0: 000000005ce4e181 (sb_writers#20){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline]
#0: 000000005ce4e181 (sb_writers#20){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360
#1: 0000000038be02d6 (&sb->s_type->i_mutex_key#27){+.+.}, at: inode_lock include/linux/fs.h:748 [inline]
#1: 0000000038be02d6 (&sb->s_type->i_mutex_key#27){+.+.}, at: fuse_open_common+0x1bc/0x2c0 fs/fuse/file.c:215
1 lock held by syz-executor.5/17345:
#0: 0000000038be02d6 (&sb->s_type->i_mutex_key#27){+.+.}, at: inode_lock include/linux/fs.h:748 [inline]
#0: 0000000038be02d6 (&sb->s_type->i_mutex_key#27){+.+.}, at: fuse_flush+0x1fd/0x5b0 fs/fuse/file.c:421
1 lock held by syz-executor.5/17404:
#0: 0000000038be02d6 (&sb->s_type->i_mutex_key#27){+.+.}, at: inode_lock include/linux/fs.h:748 [inline]
#0: 0000000038be02d6 (&sb->s_type->i_mutex_key#27){+.+.}, at: lock_mount+0xcc/0x4a0 fs/namespace.c:2039

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

NMI backtrace for cpu 1
CPU: 1 PID: 1569 Comm: khungtaskd Not tainted 4.19.190-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+0x1fc/0x2ef lib/dump_stack.c:118
nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
watchdog+0x991/0xe60 kernel/hung_task.c:287
kthread+0x33f/0x460 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: 28285 Comm: kworker/u4:12 Not tainted 4.19.190-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lock_acquire+0xfe/0x3c0 kernel/locking/lockdep.c:3906
Code: 00 00 65 48 8b 1c 25 80 df 01 00 48 8d bb 84 08 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 <83> e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 12 02 00 00 c7 83 84 08
RSP: 0018:ffff888023b87c58 EFLAGS: 00000803
RAX: ffff8880b4ce4e44 RBX: ffff8880b4ce45c0 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880b4ce4e44
RBP: ffffffff89f85ee0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3dfe30a000 CR3: 00000000a0c09000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:242 [inline]
rcu_read_lock include/linux/rcupdate.h:627 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:419 [inline]
batadv_nc_worker+0x12d/0xd50 net/batman-adv/network-coding.c:730
process_one_work+0x864/0x1570 kernel/workqueue.c:2152
worker_thread+0x64c/0x1130 kernel/workqueue.c:2295
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

syzbot

unread,
May 9, 2021, 4:22:19 PM5/9/21
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:

HEAD commit: 3c8c2309 Linux 4.19.190
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=119f61b3d00000
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=155d577dd00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13466d93d00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3dc515...@syzkaller.appspotmail.com

INFO: task syz-executor088:8123 blocked for more than 140 seconds.
Not tainted 4.19.190-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor088 D28096 8123 8121 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
fuse_wait_on_page_writeback fs/fuse/file.c:383 [inline]
fuse_wait_on_page_writeback.isra.0+0x11b/0x170 fs/fuse/file.c:379
fuse_launder_page fs/fuse/file.c:2033 [inline]
fuse_launder_page+0xb6/0xe0 fs/fuse/file.c:2026
do_launder_page mm/truncate.c:658 [inline]
invalidate_inode_pages2_range+0x786/0x10f0 mm/truncate.c:730
fuse_finish_open+0x2e2/0x590 fs/fuse/file.c:182
fuse_open_common+0x254/0x2c0 fs/fuse/file.c:222
do_dentry_open+0x4aa/0x1160 fs/open.c:796
do_last fs/namei.c:3421 [inline]
path_openat+0x793/0x2df0 fs/namei.c:3537
do_filp_open+0x18c/0x3f0 fs/namei.c:3567
do_sys_open+0x3b3/0x520 fs/open.c:1085
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4463c9
Code: Bad RIP value.
RSP: 002b:00007fa78460b2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00000000004d34e0 RCX: 00000000004463c9
RDX: 0000000000000000 RSI: 0000000000080380 RDI: 0000000020000100
RBP: 00000000004a3164 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 000000000049f158 R14: 00000000004a1160 R15: 00000000004d34e8

Showing all locks held in the system:
3 locks held by kworker/1:1/25:
#0: 000000006328d459 (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:9701 [inline]
#0: 000000006328d459 (&rq->lock){-.-.}, at: pick_next_task_fair+0x556/0x1570 kernel/sched/fair.c:6840
#1: 000000000dc79070 (rcu_read_lock){....}, at: cpu_of kernel/sched/sched.h:921 [inline]
#1: 000000000dc79070 (rcu_read_lock){....}, at: __update_idle_core+0x39/0x3e0 kernel/sched/fair.c:6057
#2: 00000000657c22fc (&base->lock){-.-.}, at: lock_timer_base+0x55/0x1b0 kernel/time/timer.c:950
1 lock held by khungtaskd/1569:
#0: 000000000dc79070 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441
1 lock held by in:imklog/7804:
#0: 000000008e9cb7d0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
2 locks held by syz-executor088/8123:
#0: 00000000f94dba2b (sb_writers#11){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline]
#0: 00000000f94dba2b (sb_writers#11){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360
#1: 000000001cc85ed3 (&sb->s_type->i_mutex_key#17){+.+.}, at: inode_lock include/linux/fs.h:748 [inline]
#1: 000000001cc85ed3 (&sb->s_type->i_mutex_key#17){+.+.}, at: fuse_open_common+0x1bc/0x2c0 fs/fuse/file.c:215

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

NMI backtrace for cpu 1
CPU: 1 PID: 1569 Comm: khungtaskd Not tainted 4.19.190-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+0x1fc/0x2ef lib/dump_stack.c:118
nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
watchdog+0x991/0xe60 kernel/hung_task.c:287
kthread+0x33f/0x460 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: 4685 Comm: systemd-journal Not tainted 4.19.190-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:261 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:69 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x1c/0x50 kernel/kcov.c:101
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 34 24 65 48 8b 04 25 80 df 01 00 65 8b 15 8c 80 9f 7e 81 e2 00 01 1f 00 75 2b <8b> 90 60 13 00 00 83 fa 02 75 20 48 8b 88 68 13 00 00 8b 80 64 13
RSP: 0018:ffff8880a115fa68 EFLAGS: 00000046
RAX: ffff8880a11543c0 RBX: ffff8880afcee640 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff812b5e14 RDI: ffff8880afcee640
RBP: 0000000080000000 R08: 000000000250e780 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000000 R12: 0000000000000000
R13: ffffea000250e788 R14: ffffea000250e780 R15: ffff88813be79b00
FS: 00007f287c1418c0(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2879513000 CR3: 00000000a1261000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__phys_addr+0x14/0x110 arch/x86/mm/physaddr.c:16
virt_to_head_page include/linux/mm.h:665 [inline]
free_block+0xa0/0x230 mm/slab.c:3420
cache_flusharray mm/slab.c:3474 [inline]
___cache_free+0x27e/0x3a0 mm/slab.c:3532
qlink_free mm/kasan/quarantine.c:147 [inline]
qlist_free_all+0x79/0x140 mm/kasan/quarantine.c:166
quarantine_reduce+0x1a9/0x230 mm/kasan/quarantine.c:259
kasan_kmalloc+0xa2/0x160 mm/kasan/kasan.c:538
slab_post_alloc_hook mm/slab.h:445 [inline]
slab_alloc mm/slab.c:3397 [inline]
kmem_cache_alloc+0x110/0x370 mm/slab.c:3557
prepare_creds+0x39/0x510 kernel/cred.c:255
do_faccessat+0x94/0x7a0 fs/open.c:359
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f287b3fc9c7
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:00007ffe0715b018 EFLAGS: 00000246 ORIG_RAX: 0000000000000015
RAX: ffffffffffffffda RBX: 00007ffe0715e040 RCX: 00007f287b3fc9c7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000558c310669a3
RBP: 00007ffe0715b160 R08: 0000558c3105c3e5 R09: 0000000000000018
R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000558c311258a0 R15: 00007ffe0715b650

syzbot

unread,
Jun 22, 2021, 12:20:17 AM6/22/21
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:

HEAD commit: cfb41ef9 Linux 4.14.237
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=137f31a4300000
kernel config: https://syzkaller.appspot.com/x/.config?x=6343ebfee99e0959
dashboard link: https://syzkaller.appspot.com/bug?extid=870bb7df35785306a4b3
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c3bda4300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16a23258300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+870bb7...@syzkaller.appspotmail.com

INFO: task syz-executor714:7983 blocked for more than 140 seconds.
Not tainted 4.14.237-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor714 D27840 7983 7981 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2808 [inline]
__schedule+0x88b/0x1de0 kernel/sched/core.c:3384
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
fuse_wait_on_page_writeback fs/fuse/file.c:382 [inline]
fuse_wait_on_page_writeback.isra.0+0xdc/0x120 fs/fuse/file.c:378
fuse_launder_page fs/fuse/file.c:2032 [inline]
fuse_launder_page+0xa2/0xd0 fs/fuse/file.c:2025
do_launder_page mm/truncate.c:609 [inline]
invalidate_inode_pages2_range+0x547/0xc00 mm/truncate.c:685
fuse_finish_open+0x262/0x500 fs/fuse/file.c:181
fuse_open_common+0x1fc/0x250 fs/fuse/file.c:221
do_dentry_open+0x44b/0xec0 fs/open.c:777
vfs_open+0x105/0x220 fs/open.c:888
do_last fs/namei.c:3428 [inline]
path_openat+0x628/0x2970 fs/namei.c:3569
do_filp_open+0x179/0x3c0 fs/namei.c:3603
do_sys_open+0x296/0x410 fs/open.c:1081
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x446399
RSP: 002b:00007fe6a31ee2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00000000004d34e0 RCX: 0000000000446399
RDX: 0000000000000000 RSI: 0000000000080380 RDI: 0000000020000100
RBP: 00000000004a3164 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 000000000049f158 R14: 00000000004a1160 R15: 00000000004d34e8

Showing all locks held in the system:
1 lock held by khungtaskd/1533:
#0: (tasklist_lock){.+.+}, at: [<ffffffff8700ce1c>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548
2 locks held by syz-executor714/7983:
#0: (sb_writers#10){.+.+}, at: [<ffffffff818dcd5a>] sb_start_write include/linux/fs.h:1549 [inline]
#0: (sb_writers#10){.+.+}, at: [<ffffffff818dcd5a>] mnt_want_write+0x3a/0xb0 fs/namespace.c:386
#1: (&sb->s_type->i_mutex_key#17){+.+.}, at: [<ffffffff822ee027>] inode_lock include/linux/fs.h:719 [inline]
#1: (&sb->s_type->i_mutex_key#17){+.+.}, at: [<ffffffff822ee027>] fuse_open_common+0x177/0x250 fs/fuse/file.c:214

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

NMI backtrace for cpu 1
CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.237-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x1b2/0x281 lib/dump_stack.c:58
nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
watchdog+0x5b9/0xb40 kernel/hung_task.c:274
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff8722cade

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