From: Dongliang Mu <[email protected]>
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: [email protected]
Signed-off-by: Dongliang Mu <[email protected]>
---
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
On Thu, Sep 29, 2022 at 1:47 PM Dongliang Mu <[email protected]> wrote:
>
> From: Dongliang Mu <[email protected]>
>
> 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: [email protected]
> Signed-off-by: Dongliang Mu <[email protected]>
> ---
> 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
>
On 10/8/22 9:00PM, Dongliang Mu wrote:
> On Thu, Sep 29, 2022 at 1:47 PM Dongliang Mu <[email protected]> wrote:
>>
>> From: Dongliang Mu <[email protected]>
>>
>> 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: [email protected]
>> Signed-off-by: Dongliang Mu <[email protected]>
>> ---
>> 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
>>
On 9/29/22 12:44AM, Dongliang Mu wrote:
> From: Dongliang Mu <[email protected]>
>
> 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: [email protected]
> Signed-off-by: Dongliang Mu <[email protected]>
> ---
> 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;
> }
>
>
On Fri, Oct 14, 2022 at 4:55 AM Dave Kleikamp <[email protected]> wrote:
>
> On 9/29/22 12:44AM, Dongliang Mu wrote:
> > From: Dongliang Mu <[email protected]>
> >
> > 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: [email protected]
> > Signed-off-by: Dongliang Mu <[email protected]>
> > ---
> > 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;
> > }
> >
> >