Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: task hung in process_measurement
INFO: task syz.0.15:6594 blocked for more than 143 seconds.
Not tainted 6.13.0-rc2-syzkaller-00018-g7cb1b4663150-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.15 state:D
stack:25784 pid:6594 tgid:6585 ppid:6461 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5369 [inline]
__schedule+0x17fb/0x4be0 kernel/sched/core.c:6756
__schedule_loop kernel/sched/core.c:6833 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6848
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905
rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write+0x1d7/0x220 kernel/locking/rwsem.c:1578
inode_lock include/linux/fs.h:818 [inline]
process_measurement+0x439/0x1fb0 security/integrity/ima/ima_main.c:250
ima_file_check+0xd9/0x120 security/integrity/ima/ima_main.c:572
security_file_post_open+0xb9/0x280 security/security.c:3121
do_open fs/namei.c:3830 [inline]
path_openat+0x2ccd/0x3590 fs/namei.c:3987
do_filp_open+0x27f/0x4e0 fs/namei.c:4014
do_sys_openat2+0x13e/0x1d0 fs/open.c:1402
do_sys_open fs/open.c:1417 [inline]
__do_sys_open fs/open.c:1425 [inline]
__se_sys_open fs/open.c:1421 [inline]
__x64_sys_open+0x225/0x270 fs/open.c:1421
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f928277fed9
RSP: 002b:00007f92834c6058 EFLAGS: 00000246
ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f9282946080 RCX: 00007f928277fed9
RDX: 0000000000000008 RSI: 0000000000002000 RDI: 0000000020001b80
RBP: 00007f92827f3cc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f9282946080 R15: 00007ffee74328d8
</TASK>
Showing all locks held in the system:
3 locks held by kworker/u8:0/11:
#0:
ffff88801ac89148
(
(wq_completion)events_unbound){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3204 [inline]
, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310
#1:
ffffc90000107d00
(
(linkwatch_work).work
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3205 [inline]
, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310
#2:
ffffffff8fc9f048
(
rtnl_mutex
){+.+.}-{4:4}
, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:281
1 lock held by khungtaskd/30:
#0:
ffffffff8e937ae0
(
rcu_read_lock
){....}-{1:3}
, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744
5 locks held by kworker/u8:4/67:
#0:
ffff88801baeb148
(
(wq_completion)netns
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3204 [inline]
, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310
#1: ffffc9000216fd00
(
net_cleanup_work
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3205 [inline]
, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310
#2:
ffffffff8fc92bd0
(pernet_ops_rwsem
){++++}-{4:4}
, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:586
#3: ffffffff8fc9f048 (rtnl_mutex){+.+.}-{4:4}
, at: default_device_exit_batch+0xe9/0xaa0 net/core/dev.c:12059
#4:
ffffffff8e93cff8
(
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline]
, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976
3 locks held by kworker/u8:6/2960:
#0:
ffff888031920948
(
(wq_completion)ipv6_addrconf
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3204 [inline]
, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310
#1:
ffffc9000cb6fd00
((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310
#2: ffffffff8fc9f048 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4755
1 lock held by dhcpcd/5489:
#0: ffffffff8fc9f048 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fc9f048 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline]
#0: ffffffff8fc9f048 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xbb0/0x20e0 net/core/rtnetlink.c:4008
2 locks held by getty/5573:
#0: ffff888031f740a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000330b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
5 locks held by syz.0.15/6586:
1 lock held by syz.0.15/6594:
#0: ffff888060c982a0 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
#0: ffff888060c982a0 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: process_measurement+0x439/0x1fb0 security/integrity/ima/ima_main.c:250
5 locks held by syz.1.16/6692:
1 lock held by syz.1.16/6693:
#0: ffff888060c98f80 (&sb->s_type->i_mutex_key
#21
){++++}-{4:4}
, at: inode_lock include/linux/fs.h:818 [inline]
, at: process_measurement+0x439/0x1fb0 security/integrity/ima/ima_main.c:250
10 locks held by syz.2.17/6709:
1 lock held by syz.2.17/6710:
#0:
ffff888075bb0f80
(&sb->s_type->i_mutex_key
#21
){++++}-{4:4}
, at: inode_lock include/linux/fs.h:818 [inline]
, at: process_measurement+0x439/0x1fb0 security/integrity/ima/ima_main.c:250
2 locks held by syz-executor/6737:
#0: ffffffff90187a68
(
&ops->srcu
#2
){.+.+}-{0:0}
, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
, at: rtnl_link_ops_get+0x22/0x250 net/core/rtnetlink.c:555
#1:
ffffffff8fc9f048
(
rtnl_mutex){+.+.}-{4:4}
, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline]
, at: rtnl_newlink+0xbb0/0x20e0 net/core/rtnetlink.c:4008
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc2-syzkaller-00018-g7cb1b4663150-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline]
watchdog+0xff6/0x1040 kernel/hung_task.c:397
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6709 Comm: syz.2.17 Not tainted 6.13.0-rc2-syzkaller-00018-g7cb1b4663150-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:io_serial_in+0x76/0xb0 drivers/tty/serial/8250/8250_port.c:409
Code: 90 35 57 fc 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 d1 09 bb fc 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c
RSP: 0018:ffffc900032c6cd8 EFLAGS: 00000002
RAX: 1ffffffff34d7400 RBX: ffffffff9a6ba5e0 RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: 0000000000000000 R08: ffffffff85482856 R09: 1ffff11004bed046
R10: dffffc0000000000 R11: ffffffff85482810 R12: dffffc0000000000
R13: ffffffff9a3b4f70 R14: 00000000000003fd R15: dffffc0000000000
FS: 00007ff0221986c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005576d5d24d98 CR3: 0000000034c90000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<TASK>
serial_in drivers/tty/serial/8250/8250.h:137 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
wait_for_lsr drivers/tty/serial/8250/8250_port.c:2087 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3334 [inline]
serial8250_console_write+0x1373/0x1ed0 drivers/tty/serial/8250/8250_port.c:3412
console_emit_next_record kernel/printk/printk.c:3122 [inline]
console_flush_all+0x869/0xeb0 kernel/printk/printk.c:3210
__console_flush_and_unlock kernel/printk/printk.c:3269 [inline]
console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309
vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432
_printk+0xd5/0x120 kernel/printk/printk.c:2457
__exfat_free_cluster+0x701/0xa00 fs/exfat/fatent.c:213
exfat_free_cluster+0x77/0xd0 fs/exfat/fatent.c:234
__exfat_truncate+0x745/0xa60 fs/exfat/file.c:235
exfat_truncate fs/exfat/file.c:257 [inline]
exfat_setattr+0x10fa/0x1a90 fs/exfat/file.c:353
notify_change+0xbca/0xe90 fs/attr.c:552
do_truncate+0x220/0x310 fs/open.c:65
handle_truncate fs/namei.c:3449 [inline]
do_open fs/namei.c:3832 [inline]
path_openat+0x2e1e/0x3590 fs/namei.c:3987
do_filp_open+0x27f/0x4e0 fs/namei.c:4014
do_sys_openat2+0x13e/0x1d0 fs/open.c:1402
do_sys_open fs/open.c:1417 [inline]
__do_sys_creat fs/open.c:1495 [inline]
__se_sys_creat fs/open.c:1489 [inline]
__x64_sys_creat+0x123/0x170 fs/open.c:1489
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff02137fed9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff022198058 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007ff021545fa0 RCX: 00007ff02137fed9
RDX: 0000000000000000 RSI: 0000000000000100 RDI: 0000000020000000
RBP: 00007ff0213f3cc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff021545fa0 R15: 00007fffd20e6358
</TASK>
Tested on:
commit: 7cb1b466 Merge tag 'locking_urgent_for_v6.13_rc3' of g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=145653e8580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c7c9f223bfe8924e
dashboard link: https://syzkaller.appspot.com/bug?extid=1de5a37cb85a2d536330
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=135868f8580000
