* [syzbot] INFO: task hung in vhost_work_dev_flush
@ 2022-02-18 23:23 syzbot
2022-02-21 8:15 ` Anirudh Rayabharam
` (2 more replies)
0 siblings, 3 replies; 10+ messages in thread
From: syzbot @ 2022-02-18 23:23 UTC (permalink / raw)
To: jasowang, kvm, linux-kernel, mst, netdev, syzkaller-bugs,
virtualization
Hello,
syzbot found the following issue on:
HEAD commit: e6251ab4551f Merge tag 'nfs-for-5.17-2' of git://git.linux..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=163caa3c700000
kernel config: https://syzkaller.appspot.com/x/.config?x=266de9da75c71a45
dashboard link: https://syzkaller.appspot.com/bug?extid=0abd373e2e50d704db87
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=108514a4700000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16ca671c700000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com
INFO: task syz-executor117:3632 blocked for more than 143 seconds.
Not tainted 5.17.0-rc3-syzkaller-00029-ge6251ab4551f #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor117 state:D stack:27512 pid: 3632 ppid: 3631 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:4986 [inline]
__schedule+0xab2/0x4db0 kernel/sched/core.c:6295
schedule+0xd2/0x260 kernel/sched/core.c:6368
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x174/0x270 kernel/sched/completion.c:138
vhost_work_dev_flush.part.0+0xbb/0xf0 drivers/vhost/vhost.c:243
vhost_work_dev_flush drivers/vhost/vhost.c:238 [inline]
vhost_poll_flush+0x5e/0x80 drivers/vhost/vhost.c:252
vhost_vsock_flush drivers/vhost/vsock.c:710 [inline]
vhost_vsock_dev_release+0x1be/0x4b0 drivers/vhost/vsock.c:757
__fput+0x286/0x9f0 fs/file_table.c:311
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
exit_task_work include/linux/task_work.h:32 [inline]
do_exit+0xb29/0x2a30 kernel/exit.c:806
do_group_exit+0xd2/0x2f0 kernel/exit.c:935
__do_sys_exit_group kernel/exit.c:946 [inline]
__se_sys_exit_group kernel/exit.c:944 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:944
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fbf04b83b89
RSP: 002b:00007fff5bc9ca18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fbf04bf8330 RCX: 00007fbf04b83b89
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 00007fff5bc9cc08
R10: 00007fff5bc9cc08 R11: 0000000000000246 R12: 00007fbf04bf8330
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/26:
#0: ffffffff8bb83c20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6460
2 locks held by getty/3275:
#0: ffff88807f0db098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244
#1: ffffc90002b662e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2077
1 lock held by vhost-3632/3633:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 26 Comm: khungtaskd Not tainted 5.17.0-rc3-syzkaller-00029-ge6251ab4551f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xc1d/0xf50 kernel/hung_task.c:369
kthread+0x2e9/0x3a0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3633 Comm: vhost-3632 Not tainted 5.17.0-rc3-syzkaller-00029-ge6251ab4551f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0xd/0x60 kernel/kcov.c:200
Code: 00 00 e9 c6 41 66 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 29 f7 89 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 a9 00 01 ff 00 74 0e
RSP: 0018:ffffc90000cd7c78 EFLAGS: 00000246
RAX: 0000000080000000 RBX: ffff888079ca8a80 RCX: 0000000080000000
RDX: 0000000000000000 RSI: ffffffff86d3f8fb RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffc90000cd7c77
R10: ffffffff86d3f8ed R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdf716a3b8 CR3: 00000000235b6000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
iotlb_access_ok+0x21b/0x3e0 drivers/vhost/vhost.c:1340
vq_meta_prefetch+0xbc/0x280 drivers/vhost/vhost.c:1366
vhost_transport_do_send_pkt+0xe0/0xfd0 drivers/vhost/vsock.c:104
vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372
kthread+0x2e9/0x3a0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: e9 c6 41 66 02 jmpq 0x26641cd
7: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1)
d: 48 8b be b0 01 00 00 mov 0x1b0(%rsi),%rdi
14: e8 b4 ff ff ff callq 0xffffffcd
19: 31 c0 xor %eax,%eax
1b: c3 retq
1c: 90 nop
1d: 65 8b 05 29 f7 89 7e mov %gs:0x7e89f729(%rip),%eax # 0x7e89f74d
24: 89 c1 mov %eax,%ecx
26: 48 8b 34 24 mov (%rsp),%rsi
* 2a: 81 e1 00 01 00 00 and $0x100,%ecx <-- trapping instruction
30: 65 48 8b 14 25 00 70 mov %gs:0x27000,%rdx
37: 02 00
39: a9 00 01 ff 00 test $0xff0100,%eax
3e: 74 0e je 0x4e
---
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 syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [syzbot] INFO: task hung in vhost_work_dev_flush 2022-02-18 23:23 [syzbot] INFO: task hung in vhost_work_dev_flush syzbot @ 2022-02-21 8:15 ` Anirudh Rayabharam 2022-02-21 14:12 ` Stefano Garzarella 2022-02-21 18:27 ` Anirudh Rayabharam 2 siblings, 0 replies; 10+ messages in thread From: Anirudh Rayabharam @ 2022-02-21 8:15 UTC (permalink / raw) To: syzbot Cc: jasowang, kvm, linux-kernel, mst, netdev, syzkaller-bugs, virtualization On Fri, Feb 18, 2022 at 03:23:24PM -0800, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: e6251ab4551f Merge tag 'nfs-for-5.17-2' of git://git.linux.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=163caa3c700000 > kernel config: https://syzkaller.appspot.com/x/.config?x=266de9da75c71a45 > dashboard link: https://syzkaller.appspot.com/bug?extid=0abd373e2e50d704db87 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=108514a4700000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16ca671c700000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com Sent a patch for this here: https://lore.kernel.org/lkml/20220221072852.31820-1-mail@anirudhrb.com/ > > INFO: task syz-executor117:3632 blocked for more than 143 seconds. > Not tainted 5.17.0-rc3-syzkaller-00029-ge6251ab4551f #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor117 state:D stack:27512 pid: 3632 ppid: 3631 flags:0x00004002 > Call Trace: > <TASK> > context_switch kernel/sched/core.c:4986 [inline] > __schedule+0xab2/0x4db0 kernel/sched/core.c:6295 > schedule+0xd2/0x260 kernel/sched/core.c:6368 > schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857 > do_wait_for_common kernel/sched/completion.c:85 [inline] > __wait_for_common kernel/sched/completion.c:106 [inline] > wait_for_common kernel/sched/completion.c:117 [inline] > wait_for_completion+0x174/0x270 kernel/sched/completion.c:138 > vhost_work_dev_flush.part.0+0xbb/0xf0 drivers/vhost/vhost.c:243 > vhost_work_dev_flush drivers/vhost/vhost.c:238 [inline] > vhost_poll_flush+0x5e/0x80 drivers/vhost/vhost.c:252 > vhost_vsock_flush drivers/vhost/vsock.c:710 [inline] > vhost_vsock_dev_release+0x1be/0x4b0 drivers/vhost/vsock.c:757 > __fput+0x286/0x9f0 fs/file_table.c:311 > task_work_run+0xdd/0x1a0 kernel/task_work.c:164 > exit_task_work include/linux/task_work.h:32 [inline] > do_exit+0xb29/0x2a30 kernel/exit.c:806 > do_group_exit+0xd2/0x2f0 kernel/exit.c:935 > __do_sys_exit_group kernel/exit.c:946 [inline] > __se_sys_exit_group kernel/exit.c:944 [inline] > __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:944 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x44/0xae > RIP: 0033:0x7fbf04b83b89 > RSP: 002b:00007fff5bc9ca18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 > RAX: ffffffffffffffda RBX: 00007fbf04bf8330 RCX: 00007fbf04b83b89 > RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 > RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 00007fff5bc9cc08 > R10: 00007fff5bc9cc08 R11: 0000000000000246 R12: 00007fbf04bf8330 > R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 > </TASK> > > Showing all locks held in the system: > 1 lock held by khungtaskd/26: > #0: ffffffff8bb83c20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6460 > 2 locks held by getty/3275: > #0: ffff88807f0db098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244 > #1: ffffc90002b662e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2077 > 1 lock held by vhost-3632/3633: > > ============================================= > > NMI backtrace for cpu 0 > CPU: 0 PID: 26 Comm: khungtaskd Not tainted 5.17.0-rc3-syzkaller-00029-ge6251ab4551f #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 > nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 > nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 > trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] > check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] > watchdog+0xc1d/0xf50 kernel/hung_task.c:369 > kthread+0x2e9/0x3a0 kernel/kthread.c:377 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > </TASK> > Sending NMI from CPU 0 to CPUs 1: > NMI backtrace for cpu 1 > CPU: 1 PID: 3633 Comm: vhost-3632 Not tainted 5.17.0-rc3-syzkaller-00029-ge6251ab4551f #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline] > RIP: 0010:__sanitizer_cov_trace_pc+0xd/0x60 kernel/kcov.c:200 > Code: 00 00 e9 c6 41 66 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 29 f7 89 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 a9 00 01 ff 00 74 0e > RSP: 0018:ffffc90000cd7c78 EFLAGS: 00000246 > RAX: 0000000080000000 RBX: ffff888079ca8a80 RCX: 0000000080000000 > RDX: 0000000000000000 RSI: ffffffff86d3f8fb RDI: 0000000000000003 > RBP: 0000000000000000 R08: 0000000000000000 R09: ffffc90000cd7c77 > R10: ffffffff86d3f8ed R11: 0000000000000001 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 > FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007ffdf716a3b8 CR3: 00000000235b6000 CR4: 00000000003506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > iotlb_access_ok+0x21b/0x3e0 drivers/vhost/vhost.c:1340 > vq_meta_prefetch+0xbc/0x280 drivers/vhost/vhost.c:1366 > vhost_transport_do_send_pkt+0xe0/0xfd0 drivers/vhost/vsock.c:104 > vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372 > kthread+0x2e9/0x3a0 kernel/kthread.c:377 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > </TASK> > ---------------- > Code disassembly (best guess): > 0: 00 00 add %al,(%rax) > 2: e9 c6 41 66 02 jmpq 0x26641cd > 7: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) > d: 48 8b be b0 01 00 00 mov 0x1b0(%rsi),%rdi > 14: e8 b4 ff ff ff callq 0xffffffcd > 19: 31 c0 xor %eax,%eax > 1b: c3 retq > 1c: 90 nop > 1d: 65 8b 05 29 f7 89 7e mov %gs:0x7e89f729(%rip),%eax # 0x7e89f74d > 24: 89 c1 mov %eax,%ecx > 26: 48 8b 34 24 mov (%rsp),%rsi > * 2a: 81 e1 00 01 00 00 and $0x100,%ecx <-- trapping instruction > 30: 65 48 8b 14 25 00 70 mov %gs:0x27000,%rdx > 37: 02 00 > 39: a9 00 01 ff 00 test $0xff0100,%eax > 3e: 74 0e je 0x4e > > > --- > 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 syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this issue, for details see: > https://goo.gl/tpsmEJ#testing-patches > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/00000000000057702a05d8532b18%40google.com. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [syzbot] INFO: task hung in vhost_work_dev_flush 2022-02-18 23:23 [syzbot] INFO: task hung in vhost_work_dev_flush syzbot 2022-02-21 8:15 ` Anirudh Rayabharam @ 2022-02-21 14:12 ` Stefano Garzarella 2022-02-21 14:37 ` syzbot 2022-02-21 15:53 ` Anirudh Rayabharam 2022-02-21 18:27 ` Anirudh Rayabharam 2 siblings, 2 replies; 10+ messages in thread From: Stefano Garzarella @ 2022-02-21 14:12 UTC (permalink / raw) To: syzbot Cc: Jason Wang, kvm, kernel list, Michael Tsirkin, netdev, syzkaller-bugs, Linux Virtualization [-- Attachment #1: Type: text/plain, Size: 7418 bytes --] #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ f71077a4d84b Patch sent upstream: https://lore.kernel.org/virtualization/20220221114916.107045-1-sgarzare@redhat.com/T/#u On Sat, Feb 19, 2022 at 12:23 AM syzbot <syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: e6251ab4551f Merge tag 'nfs-for-5.17-2' of git://git.linux.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=163caa3c700000 > kernel config: https://syzkaller.appspot.com/x/.config?x=266de9da75c71a45 > dashboard link: https://syzkaller.appspot.com/bug?extid=0abd373e2e50d704db87 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=108514a4700000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16ca671c700000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com > > INFO: task syz-executor117:3632 blocked for more than 143 seconds. > Not tainted 5.17.0-rc3-syzkaller-00029-ge6251ab4551f #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor117 state:D stack:27512 pid: 3632 ppid: 3631 flags:0x00004002 > Call Trace: > <TASK> > context_switch kernel/sched/core.c:4986 [inline] > __schedule+0xab2/0x4db0 kernel/sched/core.c:6295 > schedule+0xd2/0x260 kernel/sched/core.c:6368 > schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857 > do_wait_for_common kernel/sched/completion.c:85 [inline] > __wait_for_common kernel/sched/completion.c:106 [inline] > wait_for_common kernel/sched/completion.c:117 [inline] > wait_for_completion+0x174/0x270 kernel/sched/completion.c:138 > vhost_work_dev_flush.part.0+0xbb/0xf0 drivers/vhost/vhost.c:243 > vhost_work_dev_flush drivers/vhost/vhost.c:238 [inline] > vhost_poll_flush+0x5e/0x80 drivers/vhost/vhost.c:252 > vhost_vsock_flush drivers/vhost/vsock.c:710 [inline] > vhost_vsock_dev_release+0x1be/0x4b0 drivers/vhost/vsock.c:757 > __fput+0x286/0x9f0 fs/file_table.c:311 > task_work_run+0xdd/0x1a0 kernel/task_work.c:164 > exit_task_work include/linux/task_work.h:32 [inline] > do_exit+0xb29/0x2a30 kernel/exit.c:806 > do_group_exit+0xd2/0x2f0 kernel/exit.c:935 > __do_sys_exit_group kernel/exit.c:946 [inline] > __se_sys_exit_group kernel/exit.c:944 [inline] > __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:944 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x44/0xae > RIP: 0033:0x7fbf04b83b89 > RSP: 002b:00007fff5bc9ca18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 > RAX: ffffffffffffffda RBX: 00007fbf04bf8330 RCX: 00007fbf04b83b89 > RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 > RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 00007fff5bc9cc08 > R10: 00007fff5bc9cc08 R11: 0000000000000246 R12: 00007fbf04bf8330 > R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 > </TASK> > > Showing all locks held in the system: > 1 lock held by khungtaskd/26: > #0: ffffffff8bb83c20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6460 > 2 locks held by getty/3275: > #0: ffff88807f0db098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244 > #1: ffffc90002b662e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2077 > 1 lock held by vhost-3632/3633: > > ============================================= > > NMI backtrace for cpu 0 > CPU: 0 PID: 26 Comm: khungtaskd Not tainted 5.17.0-rc3-syzkaller-00029-ge6251ab4551f #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 > nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 > nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 > trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] > check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] > watchdog+0xc1d/0xf50 kernel/hung_task.c:369 > kthread+0x2e9/0x3a0 kernel/kthread.c:377 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > </TASK> > Sending NMI from CPU 0 to CPUs 1: > NMI backtrace for cpu 1 > CPU: 1 PID: 3633 Comm: vhost-3632 Not tainted 5.17.0-rc3-syzkaller-00029-ge6251ab4551f #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline] > RIP: 0010:__sanitizer_cov_trace_pc+0xd/0x60 kernel/kcov.c:200 > Code: 00 00 e9 c6 41 66 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 29 f7 89 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 a9 00 01 ff 00 74 0e > RSP: 0018:ffffc90000cd7c78 EFLAGS: 00000246 > RAX: 0000000080000000 RBX: ffff888079ca8a80 RCX: 0000000080000000 > RDX: 0000000000000000 RSI: ffffffff86d3f8fb RDI: 0000000000000003 > RBP: 0000000000000000 R08: 0000000000000000 R09: ffffc90000cd7c77 > R10: ffffffff86d3f8ed R11: 0000000000000001 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 > FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007ffdf716a3b8 CR3: 00000000235b6000 CR4: 00000000003506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > iotlb_access_ok+0x21b/0x3e0 drivers/vhost/vhost.c:1340 > vq_meta_prefetch+0xbc/0x280 drivers/vhost/vhost.c:1366 > vhost_transport_do_send_pkt+0xe0/0xfd0 drivers/vhost/vsock.c:104 > vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372 > kthread+0x2e9/0x3a0 kernel/kthread.c:377 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > </TASK> > ---------------- > Code disassembly (best guess): > 0: 00 00 add %al,(%rax) > 2: e9 c6 41 66 02 jmpq 0x26641cd > 7: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) > d: 48 8b be b0 01 00 00 mov 0x1b0(%rsi),%rdi > 14: e8 b4 ff ff ff callq 0xffffffcd > 19: 31 c0 xor %eax,%eax > 1b: c3 retq > 1c: 90 nop > 1d: 65 8b 05 29 f7 89 7e mov %gs:0x7e89f729(%rip),%eax # 0x7e89f74d > 24: 89 c1 mov %eax,%ecx > 26: 48 8b 34 24 mov (%rsp),%rsi > * 2a: 81 e1 00 01 00 00 and $0x100,%ecx <-- trapping instruction > 30: 65 48 8b 14 25 00 70 mov %gs:0x27000,%rdx > 37: 02 00 > 39: a9 00 01 ff 00 test $0xff0100,%eax > 3e: 74 0e je 0x4e > > > --- > 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 syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this issue, for details see: > https://goo.gl/tpsmEJ#testing-patches > [-- Attachment #2: 0001-vhost-vsock-don-t-check-owner-in-vhost_vsock_stop-wh.patch --] [-- Type: text/x-patch, Size: 2362 bytes --] From 4951112bf98d3e10d3e9557986e5ca5419ca738f Mon Sep 17 00:00:00 2001 From: Stefano Garzarella <sgarzare@redhat.com> Date: Mon, 21 Feb 2022 11:07:49 +0100 Subject: [PATCH] vhost/vsock: don't check owner in vhost_vsock_stop() while releasing vhost_vsock_stop() calls vhost_dev_check_owner() to check the device ownership. It expects current->mm to be valid. vhost_vsock_stop() is also called by vhost_vsock_dev_release() when the user has not done close(), so when we are in do_exit(). In this case current->mm is invalid and we're releasing the device, so we should clean it anyway. Let's check the owner only when vhost_vsock_stop() is called by an ioctl. Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko") Cc: stable@vger.kernel.org Reported-by: syzbot+1e3ea63db39f2b4440e0@syzkaller.appspotmail.com Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> --- drivers/vhost/vsock.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index d6ca1c7ad513..f00d2dfd72b7 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -629,16 +629,18 @@ static int vhost_vsock_start(struct vhost_vsock *vsock) return ret; } -static int vhost_vsock_stop(struct vhost_vsock *vsock) +static int vhost_vsock_stop(struct vhost_vsock *vsock, bool check_owner) { size_t i; int ret; mutex_lock(&vsock->dev.mutex); - ret = vhost_dev_check_owner(&vsock->dev); - if (ret) - goto err; + if (check_owner) { + ret = vhost_dev_check_owner(&vsock->dev); + if (ret) + goto err; + } for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { struct vhost_virtqueue *vq = &vsock->vqs[i]; @@ -753,7 +755,7 @@ static int vhost_vsock_dev_release(struct inode *inode, struct file *file) * inefficient. Room for improvement here. */ vsock_for_each_connected_socket(vhost_vsock_reset_orphans); - vhost_vsock_stop(vsock); + vhost_vsock_stop(vsock, false); vhost_vsock_flush(vsock); vhost_dev_stop(&vsock->dev); @@ -868,7 +870,7 @@ static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl, if (start) return vhost_vsock_start(vsock); else - return vhost_vsock_stop(vsock); + return vhost_vsock_stop(vsock, true); case VHOST_GET_FEATURES: features = VHOST_VSOCK_FEATURES; if (copy_to_user(argp, &features, sizeof(features))) -- 2.35.1 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [syzbot] INFO: task hung in vhost_work_dev_flush 2022-02-21 14:12 ` Stefano Garzarella @ 2022-02-21 14:37 ` syzbot 2022-02-21 15:53 ` Anirudh Rayabharam 1 sibling, 0 replies; 10+ messages in thread From: syzbot @ 2022-02-21 14:37 UTC (permalink / raw) To: jasowang, kvm, linux-kernel, mst, netdev, sgarzare, syzkaller-bugs, virtualization Hello, syzbot has tested the proposed patch and the reproducer did not trigger any issue: Reported-and-tested-by: syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com Tested on: commit: f71077a4 Merge tag 'mmc-v5.17-rc1-2' of git://git.kern.. git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ kernel config: https://syzkaller.appspot.com/x/.config?x=a78b064590b9f912 dashboard link: https://syzkaller.appspot.com/bug?extid=0abd373e2e50d704db87 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 patch: https://syzkaller.appspot.com/x/patch.diff?x=1502488e700000 Note: testing is done by a robot and is best-effort only. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [syzbot] INFO: task hung in vhost_work_dev_flush 2022-02-21 14:12 ` Stefano Garzarella 2022-02-21 14:37 ` syzbot @ 2022-02-21 15:53 ` Anirudh Rayabharam 2022-02-21 16:39 ` Stefano Garzarella 2022-02-22 10:05 ` Dan Carpenter 1 sibling, 2 replies; 10+ messages in thread From: Anirudh Rayabharam @ 2022-02-21 15:53 UTC (permalink / raw) To: Stefano Garzarella Cc: syzbot, Jason Wang, kvm, kernel list, Michael Tsirkin, netdev, syzkaller-bugs, Linux Virtualization, mail On Mon, Feb 21, 2022 at 03:12:33PM +0100, Stefano Garzarella wrote: > #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ > f71077a4d84b > > Patch sent upstream: > https://lore.kernel.org/virtualization/20220221114916.107045-1-sgarzare@redhat.com/T/#u I don't see how your patch fixes this issue. It looks unrelated. It is surprising that syzbot is happy with it. I have sent a patch for this issue here: https://lore.kernel.org/lkml/20220221072852.31820-1-mail@anirudhrb.com/ Thanks! - Anirudh > > On Sat, Feb 19, 2022 at 12:23 AM syzbot > <syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com> wrote: > > > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: e6251ab4551f Merge tag 'nfs-for-5.17-2' of git://git.linux.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=163caa3c700000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=266de9da75c71a45 > > dashboard link: https://syzkaller.appspot.com/bug?extid=0abd373e2e50d704db87 > > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=108514a4700000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16ca671c700000 > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com > > > > INFO: task syz-executor117:3632 blocked for more than 143 seconds. > > Not tainted 5.17.0-rc3-syzkaller-00029-ge6251ab4551f #0 > > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > > task:syz-executor117 state:D stack:27512 pid: 3632 ppid: 3631 flags:0x00004002 > > Call Trace: > > <TASK> > > context_switch kernel/sched/core.c:4986 [inline] > > __schedule+0xab2/0x4db0 kernel/sched/core.c:6295 > > schedule+0xd2/0x260 kernel/sched/core.c:6368 > > schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857 > > do_wait_for_common kernel/sched/completion.c:85 [inline] > > __wait_for_common kernel/sched/completion.c:106 [inline] > > wait_for_common kernel/sched/completion.c:117 [inline] > > wait_for_completion+0x174/0x270 kernel/sched/completion.c:138 > > vhost_work_dev_flush.part.0+0xbb/0xf0 drivers/vhost/vhost.c:243 > > vhost_work_dev_flush drivers/vhost/vhost.c:238 [inline] > > vhost_poll_flush+0x5e/0x80 drivers/vhost/vhost.c:252 > > vhost_vsock_flush drivers/vhost/vsock.c:710 [inline] > > vhost_vsock_dev_release+0x1be/0x4b0 drivers/vhost/vsock.c:757 > > __fput+0x286/0x9f0 fs/file_table.c:311 > > task_work_run+0xdd/0x1a0 kernel/task_work.c:164 > > exit_task_work include/linux/task_work.h:32 [inline] > > do_exit+0xb29/0x2a30 kernel/exit.c:806 > > do_group_exit+0xd2/0x2f0 kernel/exit.c:935 > > __do_sys_exit_group kernel/exit.c:946 [inline] > > __se_sys_exit_group kernel/exit.c:944 [inline] > > __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:944 > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > > entry_SYSCALL_64_after_hwframe+0x44/0xae > > RIP: 0033:0x7fbf04b83b89 > > RSP: 002b:00007fff5bc9ca18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 > > RAX: ffffffffffffffda RBX: 00007fbf04bf8330 RCX: 00007fbf04b83b89 > > RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 > > RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 00007fff5bc9cc08 > > R10: 00007fff5bc9cc08 R11: 0000000000000246 R12: 00007fbf04bf8330 > > R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 > > </TASK> > > > > Showing all locks held in the system: > > 1 lock held by khungtaskd/26: > > #0: ffffffff8bb83c20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6460 > > 2 locks held by getty/3275: > > #0: ffff88807f0db098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244 > > #1: ffffc90002b662e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2077 > > 1 lock held by vhost-3632/3633: > > > > ============================================= > > > > NMI backtrace for cpu 0 > > CPU: 0 PID: 26 Comm: khungtaskd Not tainted 5.17.0-rc3-syzkaller-00029-ge6251ab4551f #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > Call Trace: > > <TASK> > > __dump_stack lib/dump_stack.c:88 [inline] > > dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 > > nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 > > nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 > > trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] > > check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] > > watchdog+0xc1d/0xf50 kernel/hung_task.c:369 > > kthread+0x2e9/0x3a0 kernel/kthread.c:377 > > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > > </TASK> > > Sending NMI from CPU 0 to CPUs 1: > > NMI backtrace for cpu 1 > > CPU: 1 PID: 3633 Comm: vhost-3632 Not tainted 5.17.0-rc3-syzkaller-00029-ge6251ab4551f #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline] > > RIP: 0010:__sanitizer_cov_trace_pc+0xd/0x60 kernel/kcov.c:200 > > Code: 00 00 e9 c6 41 66 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 29 f7 89 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 a9 00 01 ff 00 74 0e > > RSP: 0018:ffffc90000cd7c78 EFLAGS: 00000246 > > RAX: 0000000080000000 RBX: ffff888079ca8a80 RCX: 0000000080000000 > > RDX: 0000000000000000 RSI: ffffffff86d3f8fb RDI: 0000000000000003 > > RBP: 0000000000000000 R08: 0000000000000000 R09: ffffc90000cd7c77 > > R10: ffffffff86d3f8ed R11: 0000000000000001 R12: 0000000000000000 > > R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 > > FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 00007ffdf716a3b8 CR3: 00000000235b6000 CR4: 00000000003506e0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > Call Trace: > > <TASK> > > iotlb_access_ok+0x21b/0x3e0 drivers/vhost/vhost.c:1340 > > vq_meta_prefetch+0xbc/0x280 drivers/vhost/vhost.c:1366 > > vhost_transport_do_send_pkt+0xe0/0xfd0 drivers/vhost/vsock.c:104 > > vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372 > > kthread+0x2e9/0x3a0 kernel/kthread.c:377 > > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > > </TASK> > > ---------------- > > Code disassembly (best guess): > > 0: 00 00 add %al,(%rax) > > 2: e9 c6 41 66 02 jmpq 0x26641cd > > 7: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) > > d: 48 8b be b0 01 00 00 mov 0x1b0(%rsi),%rdi > > 14: e8 b4 ff ff ff callq 0xffffffcd > > 19: 31 c0 xor %eax,%eax > > 1b: c3 retq > > 1c: 90 nop > > 1d: 65 8b 05 29 f7 89 7e mov %gs:0x7e89f729(%rip),%eax # 0x7e89f74d > > 24: 89 c1 mov %eax,%ecx > > 26: 48 8b 34 24 mov (%rsp),%rsi > > * 2a: 81 e1 00 01 00 00 and $0x100,%ecx <-- trapping instruction > > 30: 65 48 8b 14 25 00 70 mov %gs:0x27000,%rdx > > 37: 02 00 > > 39: a9 00 01 ff 00 test $0xff0100,%eax > > 3e: 74 0e je 0x4e > > > > > > --- > > 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 syzkaller@googlegroups.com. > > > > syzbot will keep track of this issue. See: > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > syzbot can test patches for this issue, for details see: > > https://goo.gl/tpsmEJ#testing-patches > > > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/CAGxU2F4nGWxG0wymrDZzd8Hwhm2%3D8syuEB3fLMd%2Bt7bbN7qWrQ%40mail.gmail.com. > From 4951112bf98d3e10d3e9557986e5ca5419ca738f Mon Sep 17 00:00:00 2001 > From: Stefano Garzarella <sgarzare@redhat.com> > Date: Mon, 21 Feb 2022 11:07:49 +0100 > Subject: [PATCH] vhost/vsock: don't check owner in vhost_vsock_stop() while > releasing > > vhost_vsock_stop() calls vhost_dev_check_owner() to check the device > ownership. It expects current->mm to be valid. > > vhost_vsock_stop() is also called by vhost_vsock_dev_release() when > the user has not done close(), so when we are in do_exit(). In this > case current->mm is invalid and we're releasing the device, so we > should clean it anyway. > > Let's check the owner only when vhost_vsock_stop() is called > by an ioctl. > > Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko") > Cc: stable@vger.kernel.org > Reported-by: syzbot+1e3ea63db39f2b4440e0@syzkaller.appspotmail.com > Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> > --- > drivers/vhost/vsock.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c > index d6ca1c7ad513..f00d2dfd72b7 100644 > --- a/drivers/vhost/vsock.c > +++ b/drivers/vhost/vsock.c > @@ -629,16 +629,18 @@ static int vhost_vsock_start(struct vhost_vsock *vsock) > return ret; > } > > -static int vhost_vsock_stop(struct vhost_vsock *vsock) > +static int vhost_vsock_stop(struct vhost_vsock *vsock, bool check_owner) > { > size_t i; > int ret; > > mutex_lock(&vsock->dev.mutex); > > - ret = vhost_dev_check_owner(&vsock->dev); > - if (ret) > - goto err; > + if (check_owner) { > + ret = vhost_dev_check_owner(&vsock->dev); > + if (ret) > + goto err; > + } > > for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { > struct vhost_virtqueue *vq = &vsock->vqs[i]; > @@ -753,7 +755,7 @@ static int vhost_vsock_dev_release(struct inode *inode, struct file *file) > * inefficient. Room for improvement here. */ > vsock_for_each_connected_socket(vhost_vsock_reset_orphans); > > - vhost_vsock_stop(vsock); > + vhost_vsock_stop(vsock, false); > vhost_vsock_flush(vsock); > vhost_dev_stop(&vsock->dev); > > @@ -868,7 +870,7 @@ static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl, > if (start) > return vhost_vsock_start(vsock); > else > - return vhost_vsock_stop(vsock); > + return vhost_vsock_stop(vsock, true); > case VHOST_GET_FEATURES: > features = VHOST_VSOCK_FEATURES; > if (copy_to_user(argp, &features, sizeof(features))) > -- > 2.35.1 > ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [syzbot] INFO: task hung in vhost_work_dev_flush 2022-02-21 15:53 ` Anirudh Rayabharam @ 2022-02-21 16:39 ` Stefano Garzarella 2022-02-22 10:05 ` Dan Carpenter 1 sibling, 0 replies; 10+ messages in thread From: Stefano Garzarella @ 2022-02-21 16:39 UTC (permalink / raw) To: Anirudh Rayabharam Cc: syzbot, Jason Wang, kvm, kernel list, Michael Tsirkin, netdev, syzkaller-bugs, Linux Virtualization On Mon, Feb 21, 2022 at 09:23:04PM +0530, Anirudh Rayabharam wrote: >On Mon, Feb 21, 2022 at 03:12:33PM +0100, Stefano Garzarella wrote: >> #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ >> f71077a4d84b >> >> Patch sent upstream: >> https://lore.kernel.org/virtualization/20220221114916.107045-1-sgarzare@redhat.com/T/#u > >I don't see how your patch fixes this issue. It looks unrelated. It is >surprising that syzbot is happy with it. > >I have sent a patch for this issue here: >https://lore.kernel.org/lkml/20220221072852.31820-1-mail@anirudhrb.com/ It is related because the worker thread is accessing the iotlb that is going to be freed, so it could be corrupted/invalid. Your patch seems right, but simply prevents iotlb from being set for the the specific test case, so it remains NULL and iotlb_access_ok() exits immediately. Anyway, currently if nregions is 0 vhost_set_memory() sets an iotlb with no regions (the for loop is not executed), so I'm not sure iotlb_access_ok() cycles infinitely. Stefano ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [syzbot] INFO: task hung in vhost_work_dev_flush 2022-02-21 15:53 ` Anirudh Rayabharam 2022-02-21 16:39 ` Stefano Garzarella @ 2022-02-22 10:05 ` Dan Carpenter 2022-02-22 11:34 ` Anirudh Rayabharam 1 sibling, 1 reply; 10+ messages in thread From: Dan Carpenter @ 2022-02-22 10:05 UTC (permalink / raw) To: Anirudh Rayabharam Cc: Stefano Garzarella, syzbot, Jason Wang, kvm, kernel list, Michael Tsirkin, netdev, syzkaller-bugs, Linux Virtualization On Mon, Feb 21, 2022 at 09:23:04PM +0530, Anirudh Rayabharam wrote: > On Mon, Feb 21, 2022 at 03:12:33PM +0100, Stefano Garzarella wrote: > > #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ > > f71077a4d84b > > > > Patch sent upstream: > > https://lore.kernel.org/virtualization/20220221114916.107045-1-sgarzare@redhat.com/T/#u > > I don't see how your patch fixes this issue. It looks unrelated. It is > surprising that syzbot is happy with it. > > I have sent a patch for this issue here: > https://lore.kernel.org/lkml/20220221072852.31820-1-mail@anirudhrb.com/ I wasted so much time trying to figure out what this patch fixes. :P (It doesn't fix anything). regards, dan carpenter ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [syzbot] INFO: task hung in vhost_work_dev_flush 2022-02-22 10:05 ` Dan Carpenter @ 2022-02-22 11:34 ` Anirudh Rayabharam 0 siblings, 0 replies; 10+ messages in thread From: Anirudh Rayabharam @ 2022-02-22 11:34 UTC (permalink / raw) To: Dan Carpenter Cc: Stefano Garzarella, syzbot, Jason Wang, kvm, kernel list, Michael Tsirkin, netdev, syzkaller-bugs, Linux Virtualization On Tue, Feb 22, 2022 at 01:05:56PM +0300, Dan Carpenter wrote: > On Mon, Feb 21, 2022 at 09:23:04PM +0530, Anirudh Rayabharam wrote: > > On Mon, Feb 21, 2022 at 03:12:33PM +0100, Stefano Garzarella wrote: > > > #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ > > > f71077a4d84b > > > > > > Patch sent upstream: > > > https://lore.kernel.org/virtualization/20220221114916.107045-1-sgarzare@redhat.com/T/#u > > > > I don't see how your patch fixes this issue. It looks unrelated. It is > > surprising that syzbot is happy with it. > > > > I have sent a patch for this issue here: > > https://lore.kernel.org/lkml/20220221072852.31820-1-mail@anirudhrb.com/ > > I wasted so much time trying to figure out what this patch fixes. :P Sorry! The new patch is here: https://lore.kernel.org/lkml/20220221195303.13560-1-mail@anirudhrb.com/T/#u Thanks! - Anirudh. > > (It doesn't fix anything). > > regards, > dan carpenter > ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [syzbot] INFO: task hung in vhost_work_dev_flush 2022-02-18 23:23 [syzbot] INFO: task hung in vhost_work_dev_flush syzbot 2022-02-21 8:15 ` Anirudh Rayabharam 2022-02-21 14:12 ` Stefano Garzarella @ 2022-02-21 18:27 ` Anirudh Rayabharam 2022-02-21 18:40 ` syzbot 2 siblings, 1 reply; 10+ messages in thread From: Anirudh Rayabharam @ 2022-02-21 18:27 UTC (permalink / raw) To: syzbot Cc: jasowang, kvm, linux-kernel, mst, netdev, syzkaller-bugs, virtualization #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master diff --git a/drivers/vhost/iotlb.c b/drivers/vhost/iotlb.c index 670d56c879e5..fef9daa9f09f 100644 --- a/drivers/vhost/iotlb.c +++ b/drivers/vhost/iotlb.c @@ -53,8 +53,13 @@ int vhost_iotlb_add_range_ctx(struct vhost_iotlb *iotlb, void *opaque) { struct vhost_iotlb_map *map; + u64 size = last - start + 1; - if (last < start) + pr_info("vhost_iotlb_add_range: iotlb=%p, start=%llu, last=%llx, addr=%llu\n", + iotlb, start, last, addr); + + // size can overflow to 0 when start is 0 and last is (2^64 - 1). + if (last < start || size == 0) return -EFAULT; if (iotlb->limit && @@ -69,7 +74,7 @@ int vhost_iotlb_add_range_ctx(struct vhost_iotlb *iotlb, return -ENOMEM; map->start = start; - map->size = last - start + 1; + map->size = size; map->last = last; map->addr = addr; map->perm = perm; ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [syzbot] INFO: task hung in vhost_work_dev_flush 2022-02-21 18:27 ` Anirudh Rayabharam @ 2022-02-21 18:40 ` syzbot 0 siblings, 0 replies; 10+ messages in thread From: syzbot @ 2022-02-21 18:40 UTC (permalink / raw) To: jasowang, kvm, linux-kernel, mail, mst, netdev, syzkaller-bugs, virtualization Hello, syzbot has tested the proposed patch and the reproducer did not trigger any issue: Reported-and-tested-by: syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com Tested on: commit: 038101e6 Merge tag 'platform-drivers-x86-v5.17-3' of g.. git tree: upstream kernel config: https://syzkaller.appspot.com/x/.config?x=96b2c57ab158898c dashboard link: https://syzkaller.appspot.com/bug?extid=0abd373e2e50d704db87 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 patch: https://syzkaller.appspot.com/x/patch.diff?x=15e55046700000 Note: testing is done by a robot and is best-effort only. ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2022-02-22 11:35 UTC | newest] Thread overview: 10+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2022-02-18 23:23 [syzbot] INFO: task hung in vhost_work_dev_flush syzbot 2022-02-21 8:15 ` Anirudh Rayabharam 2022-02-21 14:12 ` Stefano Garzarella 2022-02-21 14:37 ` syzbot 2022-02-21 15:53 ` Anirudh Rayabharam 2022-02-21 16:39 ` Stefano Garzarella 2022-02-22 10:05 ` Dan Carpenter 2022-02-22 11:34 ` Anirudh Rayabharam 2022-02-21 18:27 ` Anirudh Rayabharam 2022-02-21 18:40 ` syzbot
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