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* [PATCH] fs: jfs: fix shift-out-of-bounds in dbAllocAG
@ 2022-09-29  5:44 Dongliang Mu
  2022-10-09  2:00 ` Dongliang Mu
  2022-10-13 20:55 ` Dave Kleikamp
  0 siblings, 2 replies; 5+ messages in thread
From: Dongliang Mu @ 2022-09-29  5:44 UTC (permalink / raw)
  To: Dave Kleikamp
  Cc: Dongliang Mu, syzbot+15342c1aa6a00fb7a438, jfs-discussion, linux-kernel

From: Dongliang Mu <mudongliangabcd@gmail.com>

Syzbot found a crash : UBSAN: shift-out-of-bounds in dbAllocAG. The
underlying bug is the missing check of bmp->db_agl2size. The field can
be greater than 32 and trigger the shift-out-of-bounds.

Fix this bug by adding a check of bmp->db_agl2size in dbMount since this
field is used in many following functions. Note that, for maintainance,
I reorganzie the error handling code of dbMount.

Reported-by: syzbot+15342c1aa6a00fb7a438@syzkaller.appspotmail.com
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
---
 fs/jfs/jfs_dmap.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 6b838d3ae7c2..4c717f245920 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -155,7 +155,7 @@ int dbMount(struct inode *ipbmap)
 	struct bmap *bmp;
 	struct dbmap_disk *dbmp_le;
 	struct metapage *mp;
-	int i;
+	int i, err;
 
 	/*
 	 * allocate/initialize the in-memory bmap descriptor
@@ -170,8 +170,8 @@ int dbMount(struct inode *ipbmap)
 			   BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage,
 			   PSIZE, 0);
 	if (mp == NULL) {
-		kfree(bmp);
-		return -EIO;
+		err = -EIO;
+		goto err_kfree_bmp;
 	}
 
 	/* copy the on-disk bmap descriptor to its in-memory version. */
@@ -181,9 +181,8 @@ int dbMount(struct inode *ipbmap)
 	bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage);
 	bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag);
 	if (!bmp->db_numag) {
-		release_metapage(mp);
-		kfree(bmp);
-		return -EINVAL;
+		err = -EINVAL;
+		goto err_release_metapage;
 	}
 
 	bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel);
@@ -194,6 +193,10 @@ int dbMount(struct inode *ipbmap)
 	bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth);
 	bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart);
 	bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size);
+	if (bmp->db_agl2size >= 32) {
+		err = -EINVAL;
+		goto err_release_metapage;
+	}
 	for (i = 0; i < MAXAG; i++)
 		bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]);
 	bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize);
@@ -214,6 +217,12 @@ int dbMount(struct inode *ipbmap)
 	BMAP_LOCK_INIT(bmp);
 
 	return (0);
+
+err_release_metapage:
+	release_metapage(mp);
+err_kfree_bmp:
+	kfree(bmp);
+	return err;
 }
 
 
-- 
2.35.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH] fs: jfs: fix shift-out-of-bounds in dbAllocAG
  2022-09-29  5:44 [PATCH] fs: jfs: fix shift-out-of-bounds in dbAllocAG Dongliang Mu
@ 2022-10-09  2:00 ` Dongliang Mu
  2022-10-10 14:13   ` Dave Kleikamp
  2022-10-13 20:55 ` Dave Kleikamp
  1 sibling, 1 reply; 5+ messages in thread
From: Dongliang Mu @ 2022-10-09  2:00 UTC (permalink / raw)
  To: Dongliang Mu
  Cc: Dave Kleikamp, syzbot+15342c1aa6a00fb7a438, jfs-discussion, linux-kernel

On Thu, Sep 29, 2022 at 1:47 PM Dongliang Mu <dzm91@hust.edu.cn> wrote:
>
> From: Dongliang Mu <mudongliangabcd@gmail.com>
>
> Syzbot found a crash : UBSAN: shift-out-of-bounds in dbAllocAG. The
> underlying bug is the missing check of bmp->db_agl2size. The field can
> be greater than 32 and trigger the shift-out-of-bounds.
>
> Fix this bug by adding a check of bmp->db_agl2size in dbMount since this
> field is used in many following functions. Note that, for maintainance,
> I reorganzie the error handling code of dbMount.
>
> Reported-by: syzbot+15342c1aa6a00fb7a438@syzkaller.appspotmail.com
> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> ---
>  fs/jfs/jfs_dmap.c | 21 +++++++++++++++------
>  1 file changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
> index 6b838d3ae7c2..4c717f245920 100644
> --- a/fs/jfs/jfs_dmap.c
> +++ b/fs/jfs/jfs_dmap.c
> @@ -155,7 +155,7 @@ int dbMount(struct inode *ipbmap)
>         struct bmap *bmp;
>         struct dbmap_disk *dbmp_le;
>         struct metapage *mp;
> -       int i;
> +       int i, err;
>
>         /*
>          * allocate/initialize the in-memory bmap descriptor
> @@ -170,8 +170,8 @@ int dbMount(struct inode *ipbmap)
>                            BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage,
>                            PSIZE, 0);
>         if (mp == NULL) {
> -               kfree(bmp);
> -               return -EIO;
> +               err = -EIO;
> +               goto err_kfree_bmp;
>         }
>
>         /* copy the on-disk bmap descriptor to its in-memory version. */
> @@ -181,9 +181,8 @@ int dbMount(struct inode *ipbmap)
>         bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage);
>         bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag);
>         if (!bmp->db_numag) {
> -               release_metapage(mp);
> -               kfree(bmp);
> -               return -EINVAL;
> +               err = -EINVAL;
> +               goto err_release_metapage;
>         }
>
>         bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel);
> @@ -194,6 +193,10 @@ int dbMount(struct inode *ipbmap)
>         bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth);
>         bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart);
>         bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size);
> +       if (bmp->db_agl2size >= 32) {
> +               err = -EINVAL;
> +               goto err_release_metapage;
> +       }
>         for (i = 0; i < MAXAG; i++)
>                 bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]);
>         bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize);
> @@ -214,6 +217,12 @@ int dbMount(struct inode *ipbmap)
>         BMAP_LOCK_INIT(bmp);
>
>         return (0);
> +
> +err_release_metapage:
> +       release_metapage(mp);
> +err_kfree_bmp:
> +       kfree(bmp);
> +       return err;
>  }
>

ping?

>
> --
> 2.35.1
>

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] fs: jfs: fix shift-out-of-bounds in dbAllocAG
  2022-10-09  2:00 ` Dongliang Mu
@ 2022-10-10 14:13   ` Dave Kleikamp
  0 siblings, 0 replies; 5+ messages in thread
From: Dave Kleikamp @ 2022-10-10 14:13 UTC (permalink / raw)
  To: Dongliang Mu, Dongliang Mu
  Cc: syzbot+15342c1aa6a00fb7a438, jfs-discussion, linux-kernel

On 10/8/22 9:00PM, Dongliang Mu wrote:
> On Thu, Sep 29, 2022 at 1:47 PM Dongliang Mu <dzm91@hust.edu.cn> wrote:
>>
>> From: Dongliang Mu <mudongliangabcd@gmail.com>
>>
>> Syzbot found a crash : UBSAN: shift-out-of-bounds in dbAllocAG. The
>> underlying bug is the missing check of bmp->db_agl2size. The field can
>> be greater than 32 and trigger the shift-out-of-bounds.
>>
>> Fix this bug by adding a check of bmp->db_agl2size in dbMount since this
>> field is used in many following functions. Note that, for maintainance,
>> I reorganzie the error handling code of dbMount.
>>
>> Reported-by: syzbot+15342c1aa6a00fb7a438@syzkaller.appspotmail.com
>> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
>> ---
>>   fs/jfs/jfs_dmap.c | 21 +++++++++++++++------
>>   1 file changed, 15 insertions(+), 6 deletions(-)
>>
>> diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
>> index 6b838d3ae7c2..4c717f245920 100644
>> --- a/fs/jfs/jfs_dmap.c
>> +++ b/fs/jfs/jfs_dmap.c
>> @@ -155,7 +155,7 @@ int dbMount(struct inode *ipbmap)
>>          struct bmap *bmp;
>>          struct dbmap_disk *dbmp_le;
>>          struct metapage *mp;
>> -       int i;
>> +       int i, err;
>>
>>          /*
>>           * allocate/initialize the in-memory bmap descriptor
>> @@ -170,8 +170,8 @@ int dbMount(struct inode *ipbmap)
>>                             BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage,
>>                             PSIZE, 0);
>>          if (mp == NULL) {
>> -               kfree(bmp);
>> -               return -EIO;
>> +               err = -EIO;
>> +               goto err_kfree_bmp;
>>          }
>>
>>          /* copy the on-disk bmap descriptor to its in-memory version. */
>> @@ -181,9 +181,8 @@ int dbMount(struct inode *ipbmap)
>>          bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage);
>>          bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag);
>>          if (!bmp->db_numag) {
>> -               release_metapage(mp);
>> -               kfree(bmp);
>> -               return -EINVAL;
>> +               err = -EINVAL;
>> +               goto err_release_metapage;
>>          }
>>
>>          bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel);
>> @@ -194,6 +193,10 @@ int dbMount(struct inode *ipbmap)
>>          bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth);
>>          bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart);
>>          bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size);
>> +       if (bmp->db_agl2size >= 32) {
>> +               err = -EINVAL;
>> +               goto err_release_metapage;
>> +       }
>>          for (i = 0; i < MAXAG; i++)
>>                  bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]);
>>          bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize);
>> @@ -214,6 +217,12 @@ int dbMount(struct inode *ipbmap)
>>          BMAP_LOCK_INIT(bmp);
>>
>>          return (0);
>> +
>> +err_release_metapage:
>> +       release_metapage(mp);
>> +err_kfree_bmp:
>> +       kfree(bmp);
>> +       return err;
>>   }
>>
> 
> ping?

Sorry, it's taking me so long to get to this. It looks good, but I'll 
give it a little better look and push it.

Shaggy

> 
>>
>> --
>> 2.35.1
>>

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] fs: jfs: fix shift-out-of-bounds in dbAllocAG
  2022-09-29  5:44 [PATCH] fs: jfs: fix shift-out-of-bounds in dbAllocAG Dongliang Mu
  2022-10-09  2:00 ` Dongliang Mu
@ 2022-10-13 20:55 ` Dave Kleikamp
  2022-10-14  8:45   ` Dongliang Mu
  1 sibling, 1 reply; 5+ messages in thread
From: Dave Kleikamp @ 2022-10-13 20:55 UTC (permalink / raw)
  To: Dongliang Mu
  Cc: Dongliang Mu, syzbot+15342c1aa6a00fb7a438, jfs-discussion, linux-kernel

On 9/29/22 12:44AM, Dongliang Mu wrote:
> From: Dongliang Mu <mudongliangabcd@gmail.com>
> 
> Syzbot found a crash : UBSAN: shift-out-of-bounds in dbAllocAG. The
> underlying bug is the missing check of bmp->db_agl2size. The field can
> be greater than 32 and trigger the shift-out-of-bounds.

The shift is done to a 64-byte value, not 32.

The volume can contain up to 2^43 blocks, which are divided up into 128 
(2^7) aggregate groups, so each AG can have 2^36 blocks, which makes 36 
a valid value for db_agl2size.

> 
> Fix this bug by adding a check of bmp->db_agl2size in dbMount since this
> field is used in many following functions. Note that, for maintainance,
> I reorganzie the error handling code of dbMount.
> 
> Reported-by: syzbot+15342c1aa6a00fb7a438@syzkaller.appspotmail.com
> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> ---
>   fs/jfs/jfs_dmap.c | 21 +++++++++++++++------
>   1 file changed, 15 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
> index 6b838d3ae7c2..4c717f245920 100644
> --- a/fs/jfs/jfs_dmap.c
> +++ b/fs/jfs/jfs_dmap.c
> @@ -155,7 +155,7 @@ int dbMount(struct inode *ipbmap)
>   	struct bmap *bmp;
>   	struct dbmap_disk *dbmp_le;
>   	struct metapage *mp;
> -	int i;
> +	int i, err;
>   
>   	/*
>   	 * allocate/initialize the in-memory bmap descriptor
> @@ -170,8 +170,8 @@ int dbMount(struct inode *ipbmap)
>   			   BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage,
>   			   PSIZE, 0);
>   	if (mp == NULL) {
> -		kfree(bmp);
> -		return -EIO;
> +		err = -EIO;
> +		goto err_kfree_bmp;
>   	}
>   
>   	/* copy the on-disk bmap descriptor to its in-memory version. */
> @@ -181,9 +181,8 @@ int dbMount(struct inode *ipbmap)
>   	bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage);
>   	bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag);
>   	if (!bmp->db_numag) {
> -		release_metapage(mp);
> -		kfree(bmp);
> -		return -EINVAL;
> +		err = -EINVAL;
> +		goto err_release_metapage;
>   	}
>   
>   	bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel);
> @@ -194,6 +193,10 @@ int dbMount(struct inode *ipbmap)
>   	bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth);
>   	bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart);
>   	bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size);
> +	if (bmp->db_agl2size >= 32) {

I think the right number here is MAXMAPSIZE - L2MAXAG, so

	if (bmp->db_agl2size > (MAXMAPSIZE - L2MAXAG)) {

> +		err = -EINVAL;
> +		goto err_release_metapage;
> +	}
>   	for (i = 0; i < MAXAG; i++)
>   		bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]);
>   	bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize);
> @@ -214,6 +217,12 @@ int dbMount(struct inode *ipbmap)
>   	BMAP_LOCK_INIT(bmp);
>   
>   	return (0);
> +
> +err_release_metapage:
> +	release_metapage(mp);
> +err_kfree_bmp:
> +	kfree(bmp);
> +	return err;
>   }
>   
>   

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] fs: jfs: fix shift-out-of-bounds in dbAllocAG
  2022-10-13 20:55 ` Dave Kleikamp
@ 2022-10-14  8:45   ` Dongliang Mu
  0 siblings, 0 replies; 5+ messages in thread
From: Dongliang Mu @ 2022-10-14  8:45 UTC (permalink / raw)
  To: Dave Kleikamp
  Cc: Dongliang Mu, syzbot+15342c1aa6a00fb7a438, jfs-discussion, linux-kernel

On Fri, Oct 14, 2022 at 4:55 AM Dave Kleikamp <dave.kleikamp@oracle.com> wrote:
>
> On 9/29/22 12:44AM, Dongliang Mu wrote:
> > From: Dongliang Mu <mudongliangabcd@gmail.com>
> >
> > Syzbot found a crash : UBSAN: shift-out-of-bounds in dbAllocAG. The
> > underlying bug is the missing check of bmp->db_agl2size. The field can
> > be greater than 32 and trigger the shift-out-of-bounds.
>
> The shift is done to a 64-byte value, not 32.
>
> The volume can contain up to 2^43 blocks, which are divided up into 128
> (2^7) aggregate groups, so each AG can have 2^36 blocks, which makes 36
> a valid value for db_agl2size.

Thanks for your explanation. Will send a v2 patch after testing in Syzbot.

>
> >
> > Fix this bug by adding a check of bmp->db_agl2size in dbMount since this
> > field is used in many following functions. Note that, for maintainance,
> > I reorganzie the error handling code of dbMount.
> >
> > Reported-by: syzbot+15342c1aa6a00fb7a438@syzkaller.appspotmail.com
> > Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> > ---
> >   fs/jfs/jfs_dmap.c | 21 +++++++++++++++------
> >   1 file changed, 15 insertions(+), 6 deletions(-)
> >
> > diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
> > index 6b838d3ae7c2..4c717f245920 100644
> > --- a/fs/jfs/jfs_dmap.c
> > +++ b/fs/jfs/jfs_dmap.c
> > @@ -155,7 +155,7 @@ int dbMount(struct inode *ipbmap)
> >       struct bmap *bmp;
> >       struct dbmap_disk *dbmp_le;
> >       struct metapage *mp;
> > -     int i;
> > +     int i, err;
> >
> >       /*
> >        * allocate/initialize the in-memory bmap descriptor
> > @@ -170,8 +170,8 @@ int dbMount(struct inode *ipbmap)
> >                          BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage,
> >                          PSIZE, 0);
> >       if (mp == NULL) {
> > -             kfree(bmp);
> > -             return -EIO;
> > +             err = -EIO;
> > +             goto err_kfree_bmp;
> >       }
> >
> >       /* copy the on-disk bmap descriptor to its in-memory version. */
> > @@ -181,9 +181,8 @@ int dbMount(struct inode *ipbmap)
> >       bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage);
> >       bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag);
> >       if (!bmp->db_numag) {
> > -             release_metapage(mp);
> > -             kfree(bmp);
> > -             return -EINVAL;
> > +             err = -EINVAL;
> > +             goto err_release_metapage;
> >       }
> >
> >       bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel);
> > @@ -194,6 +193,10 @@ int dbMount(struct inode *ipbmap)
> >       bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth);
> >       bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart);
> >       bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size);
> > +     if (bmp->db_agl2size >= 32) {
>
> I think the right number here is MAXMAPSIZE - L2MAXAG, so
>
>         if (bmp->db_agl2size > (MAXMAPSIZE - L2MAXAG)) {
>
> > +             err = -EINVAL;
> > +             goto err_release_metapage;
> > +     }
> >       for (i = 0; i < MAXAG; i++)
> >               bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]);
> >       bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize);
> > @@ -214,6 +217,12 @@ int dbMount(struct inode *ipbmap)
> >       BMAP_LOCK_INIT(bmp);
> >
> >       return (0);
> > +
> > +err_release_metapage:
> > +     release_metapage(mp);
> > +err_kfree_bmp:
> > +     kfree(bmp);
> > +     return err;
> >   }
> >
> >

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2022-10-14  8:47 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-09-29  5:44 [PATCH] fs: jfs: fix shift-out-of-bounds in dbAllocAG Dongliang Mu
2022-10-09  2:00 ` Dongliang Mu
2022-10-10 14:13   ` Dave Kleikamp
2022-10-13 20:55 ` Dave Kleikamp
2022-10-14  8:45   ` Dongliang Mu

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