[syzbot] [kernel?] UBSAN: shift-out-of-bounds in aio_iiro_16_attach

[syzbot] [kernel?] UBSAN: shift-out-of-bounds in aio_iiro_16_attach

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    a79a588fc176 Merge tag 'pm-6.16-rc5' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14a4ac8c580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5ba6cef8f153bfeb
dashboard link: https://syzkaller.appspot.com/bug?extid=f1bb7e4ea47ea12b535c
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12a4ac8c580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13fc9c8c580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-a79a588f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c7aa4e6d68b0/vmlinux-a79a588f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5d71f2c64f29/bzImage-a79a588f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f1bb7e4ea47ea12b535c@syzkaller.appspotmail.com

UBSAN: shift-out-of-bounds in drivers/comedi/drivers/aio_iiro_16.c:180:9
shift exponent 8550 is too large for 32-bit type 'int'
CPU: 2 UID: 0 PID: 6096 Comm: syz.0.16 Not tainted 6.16.0-rc4-syzkaller-00308-ga79a588fc176 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120
 ubsan_epilogue lib/ubsan.c:233 [inline]
 __ubsan_handle_shift_out_of_bounds+0x27f/0x420 lib/ubsan.c:494
 aio_iiro_16_attach drivers/comedi/drivers/aio_iiro_16.c:180 [inline]
 aio_iiro_16_attach.cold+0x19/0x1e drivers/comedi/drivers/aio_iiro_16.c:164
 comedi_device_attach+0x3b3/0x900 drivers/comedi/drivers.c:996
 do_devconfig_ioctl+0x1a7/0x580 drivers/comedi/comedi_fops.c:855
 comedi_unlocked_ioctl+0x15bb/0x2e90 drivers/comedi/comedi_fops.c:2136
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl fs/ioctl.c:893 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3eb858e929
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:00007ffc84ea1e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f3eb87b5fa0 RCX: 00007f3eb858e929
RDX: 0000200000000140 RSI: 0000000040946400 RDI: 0000000000000003
RBP: 00007f3eb8610b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3eb87b5fa0 R14: 00007f3eb87b5fa0 R15: 0000000000000003
 </TASK>
---[ end trace ]---


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot will keep track of this issue. See:
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If the report is already addressed, let syzbot know by replying with:
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If you want syzbot to run the reproducer, reply with:
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If you want to overwrite report's subsystems, reply with:
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If the report is a duplicate of another one, reply with:
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Re: [syzbot] [kernel?] UBSAN: shift-out-of-bounds in aio_iiro_16_attach

[Edward Adam Davis]

#syz test

diff --git a/drivers/comedi/drivers/aio_iiro_16.c b/drivers/comedi/drivers/aio_iiro_16.c
index b00fab0b89d4..e43730f00c8b 100644
--- a/drivers/comedi/drivers/aio_iiro_16.c
+++ b/drivers/comedi/drivers/aio_iiro_16.c
@@ -177,7 +177,8 @@ static int aio_iiro_16_attach(struct comedi_device *dev,
 	 * Digital input change of state interrupts are optionally supported
 	 * using IRQ 2-7, 10-12, 14, or 15.
 	 */
-	if ((1 << it->options[1]) & 0xdcfc) {
+	if (it->options[1] > 1 && it->options[1] < 16 &&
+	    (1 << it->options[1]) & 0xdcfc) {
 		ret = request_irq(it->options[1], aio_iiro_16_cos, 0,
 				  dev->board_name, dev);
 		if (ret == 0)

Re: [syzbot] [kernel?] UBSAN: shift-out-of-bounds in aio_iiro_16_attach

[syzbot]

Hello,

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

Reported-by: syzbot+f1bb7e4ea47ea12b535c@syzkaller.appspotmail.com
Tested-by: syzbot+f1bb7e4ea47ea12b535c@syzkaller.appspotmail.com

Tested on:

commit:         d7b8f8e2 Linux 6.16-rc5
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=121eabd4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a09d8660a55f005f
dashboard link: https://syzkaller.appspot.com/bug?extid=f1bb7e4ea47ea12b535c
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12734a8c580000

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

[PATCH] comedi: aio_iiro_16: Prevent invlaid irq number

[Edward Adam Davis]

The irq number 0x2166 passed by the reproducer is too large and is not
within the supported range [2-7, 10-12, 14, or 15], which triggers the oob.

Fixes: ad7a370c8be4 ("staging: comedi: aio_iiro_16: add command support for change of state detection")
Reported-by: syzbot+f1bb7e4ea47ea12b535c@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f1bb7e4ea47ea12b535c
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
 drivers/comedi/drivers/aio_iiro_16.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/comedi/drivers/aio_iiro_16.c b/drivers/comedi/drivers/aio_iiro_16.c
index b00fab0b89d4..e43730f00c8b 100644
--- a/drivers/comedi/drivers/aio_iiro_16.c
+++ b/drivers/comedi/drivers/aio_iiro_16.c
@@ -177,7 +177,8 @@ static int aio_iiro_16_attach(struct comedi_device *dev,
 	 * Digital input change of state interrupts are optionally supported
 	 * using IRQ 2-7, 10-12, 14, or 15.
 	 */
-	if ((1 << it->options[1]) & 0xdcfc) {
+	if (it->options[1] > 1 && it->options[1] < 16 &&
+	    (1 << it->options[1]) & 0xdcfc) {
 		ret = request_irq(it->options[1], aio_iiro_16_cos, 0,
 				  dev->board_name, dev);
 		if (ret == 0)
-- 
2.43.0

Re: [PATCH] comedi: aio_iiro_16: Prevent invlaid irq number

[Ian Abbott]

On 08/07/2025 13:37, Edward Adam Davis wrote:
> The irq number 0x2166 passed by the reproducer is too large and is not
> within the supported range [2-7, 10-12, 14, or 15], which triggers the oob.
> 
> Fixes: ad7a370c8be4 ("staging: comedi: aio_iiro_16: add command support for change of state detection")
> Reported-by: syzbot+f1bb7e4ea47ea12b535c@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=f1bb7e4ea47ea12b535c
> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> ---
>   drivers/comedi/drivers/aio_iiro_16.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/comedi/drivers/aio_iiro_16.c b/drivers/comedi/drivers/aio_iiro_16.c
> index b00fab0b89d4..e43730f00c8b 100644
> --- a/drivers/comedi/drivers/aio_iiro_16.c
> +++ b/drivers/comedi/drivers/aio_iiro_16.c
> @@ -177,7 +177,8 @@ static int aio_iiro_16_attach(struct comedi_device *dev,
>   	 * Digital input change of state interrupts are optionally supported
>   	 * using IRQ 2-7, 10-12, 14, or 15.
>   	 */
> -	if ((1 << it->options[1]) & 0xdcfc) {
> +	if (it->options[1] > 1 && it->options[1] < 16 &&
> +	    (1 << it->options[1]) & 0xdcfc) {
>   		ret = request_irq(it->options[1], aio_iiro_16_cos, 0,
>   				  dev->board_name, dev);
>   		if (ret == 0)

The patch is fine apart from the misspelling of "invalid" in the subject 
line, but I'd already submitted a patch for this before syzbot detected it:

https://lore.kernel.org/lkml/20250707134622.75403-1-abbotti@mev.co.uk/

-- 
-=( Ian Abbott <abbotti@mev.co.uk> || MEV Ltd. is a company  )=-
-=( registered in England & Wales.  Regd. number: 02862268.  )=-
-=( Regd. addr.: S11 & 12 Building 67, Europa Business Park, )=-
-=( Bird Hall Lane, STOCKPORT, SK3 0XA, UK. || www.mev.co.uk )=-

Forwarded: Re: [syzbot] [kernel?] UBSAN: shift-out-of-bounds in aio_iiro_16_attach

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: Re: [syzbot] [kernel?] UBSAN: shift-out-of-bounds in aio_iiro_16_attach
Author: xandfury@gmail.com

syzbot <syzbot+f1bb7e4ea47ea12b535c@syzkaller.appspotmail.com> writes:

> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    a79a588fc176 Merge tag ’pm-6.16-rc5’ of git://git.kernel.o..
> git tree:       upstream
> console output: <https://syzkaller.appspot.com/x/log.txt?x=14a4ac8c580000>
> kernel config:  <https://syzkaller.appspot.com/x/.config?x=5ba6cef8f153bfeb>
> dashboard link: <https://syzkaller.appspot.com/bug?extid=f1bb7e4ea47ea12b535c>
> compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      <https://syzkaller.appspot.com/x/repro.syz?x=12a4ac8c580000>
> C reproducer:   <https://syzkaller.appspot.com/x/repro.c?x=13fc9c8c580000>
>
> Downloadable assets:
> disk image (non-bootable): <https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-a79a588f.raw.xz>
> vmlinux: <https://storage.googleapis.com/syzbot-assets/c7aa4e6d68b0/vmlinux-a79a588f.xz>
> kernel image: <https://storage.googleapis.com/syzbot-assets/5d71f2c64f29/bzImage-a79a588f.xz>
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+f1bb7e4ea47ea12b535c@syzkaller.appspotmail.com
>
> UBSAN: shift-out-of-bounds in drivers/comedi/drivers/aio_iiro_16.c:180:9
> shift exponent 8550 is too large for 32-bit type ’int’
> CPU: 2 UID: 0 PID: 6096 Comm: syz.0.16 Not tainted 6.16.0-rc4-syzkaller-00308-ga79a588fc176 #0 PREEMPT(full) 
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
> Call Trace:
>  <TASK>
>  __dump_stack lib/dump_stack.c:94 [inline]
>  dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120
>  ubsan_epilogue lib/ubsan.c:233 [inline]
>  __ubsan_handle_shift_out_of_bounds+0x27f/0x420 lib/ubsan.c:494
>  aio_iiro_16_attach drivers/comedi/drivers/aio_iiro_16.c:180 [inline]
>  aio_iiro_16_attach.cold+0x19/0x1e drivers/comedi/drivers/aio_iiro_16.c:164
>  comedi_device_attach+0x3b3/0x900 drivers/comedi/drivers.c:996
>  do_devconfig_ioctl+0x1a7/0x580 drivers/comedi/comedi_fops.c:855
>  comedi_unlocked_ioctl+0x15bb/0x2e90 drivers/comedi/comedi_fops.c:2136
>  vfs_ioctl fs/ioctl.c:51 [inline]
>  __do_sys_ioctl fs/ioctl.c:907 [inline]
>  __se_sys_ioctl fs/ioctl.c:893 [inline]
>  __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:893
>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>  do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7f3eb858e929
> 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:00007ffc84ea1e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 00007f3eb87b5fa0 RCX: 00007f3eb858e929
> RDX: 0000200000000140 RSI: 0000000040946400 RDI: 0000000000000003
> RBP: 00007f3eb8610b39 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007f3eb87b5fa0 R14: 00007f3eb87b5fa0 R15: 0000000000000003
>  </TASK>
> —[ end trace ]—
>
>
> —
> 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.
>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to overwrite report’s subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 66acb1586737

Re: [PATCH] comedi: aio_iiro_16: Prevent invlaid irq number

[Abhinav Saxena]

[-- Attachment #1: Type: text/plain, Size: 1691 bytes --]

Ian Abbott <abbotti@mev.co.uk> writes:

> On 08/07/2025 13:37, Edward Adam Davis wrote:
>> The irq number 0x2166 passed by the reproducer is too large and is not
>> within the supported range [2-7, 10-12, 14, or 15], which triggers the oob.
>> Fixes: ad7a370c8be4 (“staging: comedi: aio_iiro_16: add command
>> support for change of state detection”)
>> Reported-by: syzbot+f1bb7e4ea47ea12b535c@syzkaller.appspotmail.com
>> Closes: <https://syzkaller.appspot.com/bug?extid=f1bb7e4ea47ea12b535c>
>> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
>> —
>>   drivers/comedi/drivers/aio_iiro_16.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>> diff –git a/drivers/comedi/drivers/aio_iiro_16.c
>> b/drivers/comedi/drivers/aio_iiro_16.c
>> index b00fab0b89d4..e43730f00c8b 100644
>> — a/drivers/comedi/drivers/aio_iiro_16.c
>> +++ b/drivers/comedi/drivers/aio_iiro_16.c
>> @@ -177,7 +177,8 @@ static int aio_iiro_16_attach(struct comedi_device *dev,
>>   	 * Digital input change of state interrupts are optionally supported
>>   	 * using IRQ 2-7, 10-12, 14, or 15.
>>   	 */
>> -	if ((1 << it->options[1]) & 0xdcfc) {
>> +	if (it->options[1] > 1 && it->options[1] < 16 &&
>> +	    (1 << it->options[1]) & 0xdcfc) {
>>   		ret = request_irq(it->options[1], aio_iiro_16_cos, 0,
>>   				  dev->board_name, dev);
>>   		if (ret == 0)
>
> The patch is fine apart from the misspelling of “invalid” in the subject
> line, but I’d already submitted a patch for this before syzbot detected
> it:
>
> <https://lore.kernel.org/lkml/20250707134622.75403-1-abbotti@mev.co.uk/>

#syz fix: comedi: aio_iiro_16: Fix bit shift out of bounds