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[PATCH] ocfs2: Fix shift-out-of-bounds UBSAN bug in ocfs2_verify_volume()

qasdev posted 1 patch 1 year, 5 months ago
There is a newer version of this series
fs/ocfs2/super.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
[PATCH] ocfs2: Fix shift-out-of-bounds UBSAN bug in ocfs2_verify_volume()
Posted by qasdev 1 year, 5 months ago 
From ad1ca2fd2ecf4eb7ec2c76fcbbf34639f0ad87ca Mon Sep 17 00:00:00 2001
From: Qasim Ijaz <qasdev00@gmail.com>
Date: Fri, 16 Aug 2024 02:30:25 +0100
Subject: [PATCH] ocfs2: Fix shift-out-of-bounds UBSAN bug in
 ocfs2_verify_volume()

This patch addresses a shift-out-of-bounds error in the 
ocfs2_verify_volume() function, identified by UBSAN. The bug was triggered 
by an invalid s_clustersize_bits value (e.g., 1548), which caused the 
expression "1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits)" 
to exceed the limits of a 32-bit integer, 
leading to an out-of-bounds shift.

Reported-by: syzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=f3fff775402751ebb471
Tested-by: syzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
---
 fs/ocfs2/super.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index afee70125ae3..1e43cdca7f40 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -2357,8 +2357,12 @@ static int ocfs2_verify_volume(struct ocfs2_dinode *di,
 			     (unsigned long long)bh->b_blocknr);
 		} else if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 12 ||
 			    le32_to_cpu(di->id2.i_super.s_clustersize_bits) > 20) {
-			mlog(ML_ERROR, "bad cluster size found: %u\n",
-			     1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
+			if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 32)
+				mlog(ML_ERROR, "bad cluster size found: %u\n",
+				     1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
+			else
+				mlog(ML_ERROR, "invalid cluster size bit value: %u\n",
+				     le32_to_cpu(di->id2.i_super.s_clustersize_bits));
 		} else if (!le64_to_cpu(di->id2.i_super.s_root_blkno)) {
 			mlog(ML_ERROR, "bad root_blkno: 0\n");
 		} else if (!le64_to_cpu(di->id2.i_super.s_system_dir_blkno)) {
-- 
2.30.2
Re: [PATCH] ocfs2: Fix shift-out-of-bounds UBSAN bug in ocfs2_verify_volume()
Posted by Heming Zhao 1 year, 5 months ago 
On 8/16/24 21:41, qasdev wrote:
>  From ad1ca2fd2ecf4eb7ec2c76fcbbf34639f0ad87ca Mon Sep 17 00:00:00 2001
> From: Qasim Ijaz <qasdev00@gmail.com>
> Date: Fri, 16 Aug 2024 02:30:25 +0100
> Subject: [PATCH] ocfs2: Fix shift-out-of-bounds UBSAN bug in
>   ocfs2_verify_volume()
> 
> This patch addresses a shift-out-of-bounds error in the
> ocfs2_verify_volume() function, identified by UBSAN. The bug was triggered
> by an invalid s_clustersize_bits value (e.g., 1548), which caused the
> expression "1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits)"
> to exceed the limits of a 32-bit integer,
> leading to an out-of-bounds shift.
> 
> Reported-by: syzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
> Closes: https://syzkaller.appspot.com/bug?extid=f3fff775402751ebb471
> Tested-by: syzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
> Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
> ---
>   fs/ocfs2/super.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
> index afee70125ae3..1e43cdca7f40 100644
> --- a/fs/ocfs2/super.c
> +++ b/fs/ocfs2/super.c
> @@ -2357,8 +2357,12 @@ static int ocfs2_verify_volume(struct ocfs2_dinode *di,
>   			     (unsigned long long)bh->b_blocknr);
>   		} else if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 12 ||
>   			    le32_to_cpu(di->id2.i_super.s_clustersize_bits) > 20) {
> -			mlog(ML_ERROR, "bad cluster size found: %u\n",
> -			     1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
> +			if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 32)
> +				mlog(ML_ERROR, "bad cluster size found: %u\n",
> +				     1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
> +			else
> +				mlog(ML_ERROR, "invalid cluster size bit value: %u\n",
> +				     le32_to_cpu(di->id2.i_super.s_clustersize_bits));

I prefer to use concise code to fix the error.
Do you like below code?
-		mlog(ML_ERROR, "bad cluster size found: %u\n",
-			     1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
+		mlog(ML_ERROR, "bad cluster size bit found: %u\n",
+			     le32_to_cpu(di->id2.i_super.s_clustersize_bits));

Thanks,
Heming

>   		} else if (!le64_to_cpu(di->id2.i_super.s_root_blkno)) {
>   			mlog(ML_ERROR, "bad root_blkno: 0\n");
>   		} else if (!le64_to_cpu(di->id2.i_super.s_system_dir_blkno)) {
Re: [PATCH] ocfs2: Fix shift-out-of-bounds UBSAN bug in ocfs2_verify_volume()
Posted by Joseph Qi 1 year, 5 months ago 

On 8/18/24 7:43 PM, Heming Zhao wrote:
> On 8/16/24 21:41, qasdev wrote:
>>  From ad1ca2fd2ecf4eb7ec2c76fcbbf34639f0ad87ca Mon Sep 17 00:00:00 2001
>> From: Qasim Ijaz <qasdev00@gmail.com>
>> Date: Fri, 16 Aug 2024 02:30:25 +0100
>> Subject: [PATCH] ocfs2: Fix shift-out-of-bounds UBSAN bug in
>>   ocfs2_verify_volume()
>>

The above should be eliminated from patch body. 

>> This patch addresses a shift-out-of-bounds error in the
>> ocfs2_verify_volume() function, identified by UBSAN. The bug was triggered
>> by an invalid s_clustersize_bits value (e.g., 1548), which caused the
>> expression "1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits)"
>> to exceed the limits of a 32-bit integer,
>> leading to an out-of-bounds shift.
>>
>> Reported-by: syzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
>> Closes: https://syzkaller.appspot.com/bug?extid=f3fff775402751ebb471
>> Tested-by: syzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
>> Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
>> ---
>>   fs/ocfs2/super.c | 8 ++++++--
>>   1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
>> index afee70125ae3..1e43cdca7f40 100644
>> --- a/fs/ocfs2/super.c
>> +++ b/fs/ocfs2/super.c
>> @@ -2357,8 +2357,12 @@ static int ocfs2_verify_volume(struct ocfs2_dinode *di,
>>                    (unsigned long long)bh->b_blocknr);
>>           } else if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 12 ||
>>                   le32_to_cpu(di->id2.i_super.s_clustersize_bits) > 20) {
>> -            mlog(ML_ERROR, "bad cluster size found: %u\n",
>> -                 1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
>> +            if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 32)
>> +                mlog(ML_ERROR, "bad cluster size found: %u\n",
>> +                     1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
>> +            else
>> +                mlog(ML_ERROR, "invalid cluster size bit value: %u\n",
>> +                     le32_to_cpu(di->id2.i_super.s_clustersize_bits));
> 
> I prefer to use concise code to fix the error.
> Do you like below code?
> -        mlog(ML_ERROR, "bad cluster size found: %u\n",
> -                 1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
> +        mlog(ML_ERROR, "bad cluster size bit found: %u\n",
> +                 le32_to_cpu(di->id2.i_super.s_clustersize_bits));
> 

Agree. qasdev, Could you please update and send v2?

Thanks,
Joseph
[PATCH v2] ocfs2: Fix shift-out-of-bounds UBSAN bug in ocfs2_verify_volume()
Posted by qasdev 1 year, 5 months ago 
On Mon, Aug 19, 2024 at 10:52:29AM +0800, Joseph Qi wrote:
> 
> 
> On 8/18/24 7:43 PM, Heming Zhao wrote:
> > On 8/16/24 21:41, qasdev wrote:
> >>  From ad1ca2fd2ecf4eb7ec2c76fcbbf34639f0ad87ca Mon Sep 17 00:00:00 2001
> >> From: Qasim Ijaz <qasdev00@gmail.com>
> >> Date: Fri, 16 Aug 2024 02:30:25 +0100
> >> Subject: [PATCH] ocfs2: Fix shift-out-of-bounds UBSAN bug in
> >>   ocfs2_verify_volume()
> >>
> 
> The above should be eliminated from patch body. 
> 
> >> This patch addresses a shift-out-of-bounds error in the
> >> ocfs2_verify_volume() function, identified by UBSAN. The bug was triggered
> >> by an invalid s_clustersize_bits value (e.g., 1548), which caused the
> >> expression "1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits)"
> >> to exceed the limits of a 32-bit integer,
> >> leading to an out-of-bounds shift.
> >>
> >> Reported-by: syzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
> >> Closes: https://syzkaller.appspot.com/bug?extid=f3fff775402751ebb471
> >> Tested-by: syzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
> >> Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
> >> ---
> >>   fs/ocfs2/super.c | 8 ++++++--
> >>   1 file changed, 6 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
> >> index afee70125ae3..1e43cdca7f40 100644
> >> --- a/fs/ocfs2/super.c
> >> +++ b/fs/ocfs2/super.c
> >> @@ -2357,8 +2357,12 @@ static int ocfs2_verify_volume(struct ocfs2_dinode *di,
> >>                    (unsigned long long)bh->b_blocknr);
> >>           } else if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 12 ||
> >>                   le32_to_cpu(di->id2.i_super.s_clustersize_bits) > 20) {
> >> -            mlog(ML_ERROR, "bad cluster size found: %u\n",
> >> -                 1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
> >> +            if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 32)
> >> +                mlog(ML_ERROR, "bad cluster size found: %u\n",
> >> +                     1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
> >> +            else
> >> +                mlog(ML_ERROR, "invalid cluster size bit value: %u\n",
> >> +                     le32_to_cpu(di->id2.i_super.s_clustersize_bits));
> > 
> > I prefer to use concise code to fix the error.
> > Do you like below code?
> > -        mlog(ML_ERROR, "bad cluster size found: %u\n",
> > -                 1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
> > +        mlog(ML_ERROR, "bad cluster size bit found: %u\n",
> > +                 le32_to_cpu(di->id2.i_super.s_clustersize_bits));
> > 
> 
> Agree. qasdev, Could you please update and send v2?
> 
> Thanks,
> Joseph

Thanks for the feedback. After considering the input, I've refined the patch 
to make it more concise. I've updated the patch and included it below:


This patch addresses a shift-out-of-bounds error in the 
ocfs2_verify_volume() function, identified by UBSAN. The bug was triggered 
by an invalid s_clustersize_bits value (e.g., 1548), which caused the 
expression "1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits)" 
to exceed the limits of a 32-bit integer, 
leading to an out-of-bounds shift.

Reported-by: syzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=f3fff775402751ebb471
Tested-by: syzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
---
 fs/ocfs2/super.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index afee70125ae3..b704983b2112 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -2357,8 +2357,8 @@ static int ocfs2_verify_volume(struct ocfs2_dinode *di,
                     (unsigned long long)bh->b_blocknr);
             } else if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 12 ||
                     le32_to_cpu(di->id2.i_super.s_clustersize_bits) > 20) {
-                   mlog(ML_ERROR, "bad cluster size found: %u\n",
-                        1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
+                   mlog(ML_ERROR, "bad cluster size bit found: %u\n",
+                        le32_to_cpu(di->id2.i_super.s_clustersize_bits));
             } else if (!le64_to_cpu(di->id2.i_super.s_root_blkno)) {
                     mlog(ML_ERROR, "bad root_blkno: 0\n");
             } else if (!le64_to_cpu(di->id2.i_super.s_system_dir_blkno)) {
-- 
2.30.2
Re: [PATCH v2] ocfs2: Fix shift-out-of-bounds UBSAN bug in ocfs2_verify_volume()
Posted by Joseph Qi 1 year, 5 months ago 

On 8/20/24 9:03 AM, qasdev wrote:
> On Mon, Aug 19, 2024 at 10:52:29AM +0800, Joseph Qi wrote:
>>
>>
>> On 8/18/24 7:43 PM, Heming Zhao wrote:
>>> On 8/16/24 21:41, qasdev wrote:
>>>>  From ad1ca2fd2ecf4eb7ec2c76fcbbf34639f0ad87ca Mon Sep 17 00:00:00 2001
>>>> From: Qasim Ijaz <qasdev00@gmail.com>
>>>> Date: Fri, 16 Aug 2024 02:30:25 +0100
>>>> Subject: [PATCH] ocfs2: Fix shift-out-of-bounds UBSAN bug in
>>>>   ocfs2_verify_volume()
>>>>
>>
>> The above should be eliminated from patch body. 
>>
>>>> This patch addresses a shift-out-of-bounds error in the
>>>> ocfs2_verify_volume() function, identified by UBSAN. The bug was triggered
>>>> by an invalid s_clustersize_bits value (e.g., 1548), which caused the
>>>> expression "1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits)"
>>>> to exceed the limits of a 32-bit integer,
>>>> leading to an out-of-bounds shift.
>>>>
>>>> Reported-by: syzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
>>>> Closes: https://syzkaller.appspot.com/bug?extid=f3fff775402751ebb471
>>>> Tested-by: syzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
>>>> Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
>>>> ---
>>>>   fs/ocfs2/super.c | 8 ++++++--
>>>>   1 file changed, 6 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
>>>> index afee70125ae3..1e43cdca7f40 100644
>>>> --- a/fs/ocfs2/super.c
>>>> +++ b/fs/ocfs2/super.c
>>>> @@ -2357,8 +2357,12 @@ static int ocfs2_verify_volume(struct ocfs2_dinode *di,
>>>>                    (unsigned long long)bh->b_blocknr);
>>>>           } else if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 12 ||
>>>>                   le32_to_cpu(di->id2.i_super.s_clustersize_bits) > 20) {
>>>> -            mlog(ML_ERROR, "bad cluster size found: %u\n",
>>>> -                 1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
>>>> +            if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 32)
>>>> +                mlog(ML_ERROR, "bad cluster size found: %u\n",
>>>> +                     1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
>>>> +            else
>>>> +                mlog(ML_ERROR, "invalid cluster size bit value: %u\n",
>>>> +                     le32_to_cpu(di->id2.i_super.s_clustersize_bits));
>>>
>>> I prefer to use concise code to fix the error.
>>> Do you like below code?
>>> -        mlog(ML_ERROR, "bad cluster size found: %u\n",
>>> -                 1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
>>> +        mlog(ML_ERROR, "bad cluster size bit found: %u\n",
>>> +                 le32_to_cpu(di->id2.i_super.s_clustersize_bits));
>>>
>>
>> Agree. qasdev, Could you please update and send v2?
>>
>> Thanks,
>> Joseph
> 
> Thanks for the feedback. After considering the input, I've refined the patch 
> to make it more concise. I've updated the patch and included it below:
> 
Hi, please send v2 as a standalone thread.

Thanks,
Joseph

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