[syzbot] [bluetooth?] [usb?] BUG: soft lockup in hci_cmd_timeout

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 8867bbd4a056 mm: arm64: Fix the out-of-bounds issue in con..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=112ad20a980000
kernel config: https://syzkaller.appspot.com/x/.config?x=3b4350cf56c61c80
dashboard link: https://syzkaller.appspot.com/bug?extid=1b2abad17596ad03dcff
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1112d2ce980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12c37286980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6ea21f50498b/disk-8867bbd4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e2fed09364aa/vmlinux-8867bbd4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4860173c7a18/Image-8867bbd4.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1b2aba...@syzkaller.appspotmail.com

cdc_wdm 1-1:1.0: nonzero urb status received: -71
cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes
cdc_wdm 1-1:1.0: nonzero urb status received: -71
cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes
watchdog: BUG: soft lockup - CPU#0 stuck for 27s! [kworker/u9:2:6293]
CPU#0 Utilization every 4s during lockup:
#1: 97% system, 1% softirq, 4% hardirq, 0% idle
#2: 98% system, 1% softirq, 3% hardirq, 0% idle
#3: 97% system, 0% softirq, 3% hardirq, 0% idle
#4: 98% system, 1% softirq, 3% hardirq, 0% idle
#5: 98% system, 1% softirq, 3% hardirq, 0% idle
Modules linked in:
irq event stamp: 150196
hardirqs last enabled at (150195): [<ffff80008037bc00>] console_emit_next_record kernel/printk/printk.c:2935 [inline]
hardirqs last enabled at (150195): [<ffff80008037bc00>] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994
hardirqs last disabled at (150196): [<ffff80008af10b00>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline]
hardirqs last disabled at (150196): [<ffff80008af10b00>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551
softirqs last enabled at (150190): [<ffff8000801ea530>] softirq_handle_end kernel/softirq.c:400 [inline]
softirqs last enabled at (150190): [<ffff8000801ea530>] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582
softirqs last disabled at (150185): [<ffff800080020de8>] __do_softirq+0x14/0x20 kernel/softirq.c:588
CPU: 0 PID: 6293 Comm: kworker/u9:2 Tainted: G W 6.10.0-rc2-syzkaller-g8867bbd4a056 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: hci0 hci_cmd_timeout
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:176 [inline]
pc : arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline]
pc : console_emit_next_record kernel/printk/printk.c:2935 [inline]
pc : console_flush_all+0x67c/0xb74 kernel/printk/printk.c:2994
lr : console_emit_next_record kernel/printk/printk.c:2935 [inline]
lr : console_flush_all+0x678/0xb74 kernel/printk/printk.c:2994
sp : ffff8000993f7360
x29: ffff8000993f7460 x28: ffff8000993f7510 x27: 0000000000000001
x26: ffff80009090b530 x25: ffff80009090b520 x24: dfff800000000000
x23: 1ffff000121216af x22: dfff800000000000 x21: ffff80009090b578
x20: 0000000000000000 x19: 00000000000000c0 x18: ffff8000993f7298
x17: 6965636572207375 x16: ffff80008033878c x15: 0000000000000001
x14: 1ffff00011e379c8 x13: 0000000000000000 x12: 0000000000000003
x11: 0000000000000001 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : ffff0000d3a39e40 x7 : ffff800080381d44 x6 : 0000000000000000
x5 : 0000000000000001 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000006 x1 : 0000000000000080 x0 : 0000000000000000
Call trace:
__daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline]
arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline]
console_emit_next_record kernel/printk/printk.c:2935 [inline]
console_flush_all+0x67c/0xb74 kernel/printk/printk.c:2994
console_unlock+0xec/0x3d4 kernel/printk/printk.c:3063
vprintk_emit+0x1ec/0x350 kernel/printk/printk.c:2345
vprintk_default+0xa0/0xe4 kernel/printk/printk.c:2360
vprintk+0x200/0x2d4 kernel/printk/printk_safe.c:45
_printk+0xdc/0x128 kernel/printk/printk.c:2370
bt_err+0xfc/0x144 net/bluetooth/lib.c:296
hci_cmd_timeout+0xd8/0x1cc net/bluetooth/hci_core.c:1528
process_one_work+0x7b0/0x15e8 kernel/workqueue.c:3231
process_scheduled_works kernel/workqueue.c:3312 [inline]
worker_thread+0x938/0xef4 kernel/workqueue.c:3393
kthread+0x288/0x310 kernel/kthread.c:389
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 6.10.0-rc2-syzkaller-g8867bbd4a056 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : arch_local_irq_enable+0x8/0xc arch/arm64/include/asm/irqflags.h:50
lr : default_idle_call+0xf8/0x128 kernel/sched/idle.c:124
sp : ffff800093e97d10
x29: ffff800093e97d10 x28: dfff800000000000 x27: 1ffff000127d2fb0
x26: ffff80008efed000 x25: 0000000000000000 x24: 0000000000000002
x23: 1ffff00011dfdaad x22: ffff80008efed568 x21: 0000000000000000
x20: ffff0000c1b70000 x19: ffff8000802e6e08 x18: 1fffe000367b6bde
x17: ffff80008efed000 x16: ffff8000802e66cc x15: 0000000000000001
x14: 1fffe000367b8941 x13: 0000000000000000 x12: 0000000000000003
x11: 0000000000000001 x10: 0000000000000003 x9 : 0000000000000000
x8 : 00000000000b17a9 x7 : ffff80008047f238 x6 : 0000000000000000
x5 : 0000000000000001 x4 : 0000000000000001 x3 : ffff80008af14fe8
x2 : 0000000000000000 x1 : ffff80008b0900a0 x0 : ffff800124e80000
Call trace:
__daif_local_irq_enable arch/arm64/include/asm/irqflags.h:26 [inline]
arch_local_irq_enable+0x8/0xc arch/arm64/include/asm/irqflags.h:48
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1f0/0x4e4 kernel/sched/idle.c:332
cpu_startup_entry+0x5c/0x74 kernel/sched/idle.c:430
secondary_start_kernel+0x1bc/0x1e4 arch/arm64/kernel/smp.c:279
__secondary_switched+0xb8/0xbc arch/arm64/kernel/head.S:417


---
This report is generated by a bot. It may contain errors.
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

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#syz test: git://repo/address.git branch-or-commit-hash
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#syz undup

[Alan Stern]

This patch fixed the problem in a different syzbot lockup. Let's see if
it also fixes this one. The console log output suggests that it will.

Alan Stern

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git 8867bbd4a056

Index: usb-devel/drivers/usb/class/cdc-wdm.c
===================================================================
--- usb-devel.orig/drivers/usb/class/cdc-wdm.c
+++ usb-devel/drivers/usb/class/cdc-wdm.c
@@ -266,14 +266,14 @@ static void wdm_int_callback(struct urb
dev_err(&desc->intf->dev, "Stall on int endpoint\n");
goto sw; /* halt is cleared in work */
default:
- dev_err(&desc->intf->dev,
+ dev_err_ratelimited(&desc->intf->dev,
"nonzero urb status received: %d\n", status);
break;
}
}

if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
- dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
+ dev_err_ratelimited(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
urb->actual_length);
goto exit;
}

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+1b2aba...@syzkaller.appspotmail.com

Tested on:

commit: 8867bbd4 mm: arm64: Fix the out-of-bounds issue in con..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1258bf6a980000

kernel config: https://syzkaller.appspot.com/x/.config?x=3b4350cf56c61c80
dashboard link: https://syzkaller.appspot.com/bug?extid=1b2abad17596ad03dcff
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

patch: https://syzkaller.appspot.com/x/patch.diff?x=137d960e980000

Note: testing is done by a robot and is best-effort only.