[PATCH-v2] jfs: fix slab-out-of-bounds Read in dtSearch

[PATCH-v2] jfs: fix slab-out-of-bounds Read in dtSearch

[Manas Ghandat]

Currently while searching for current page in the sorted entry table
of the page there is a out of bound access. Added a bound check to fix
the error.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202310241724.Ed02yUz9-lkp@intel.com/
Signed-off-by: Manas Ghandat <ghandatmanas@gmail.com>
---
V1 -> V2 : Removed redundant check on stbl

 fs/jfs/jfs_dtree.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/jfs/jfs_dtree.c b/fs/jfs/jfs_dtree.c
index 92b7c533407c..cf67d32d5b7f 100644
--- a/fs/jfs/jfs_dtree.c
+++ b/fs/jfs/jfs_dtree.c
@@ -633,6 +633,9 @@ int dtSearch(struct inode *ip, struct component_name * key, ino_t * data,
 		for (base = 0, lim = p->header.nextindex; lim; lim >>= 1) {
 			index = base + (lim >> 1);
 
+			if (stbl[index] < 0)
+				goto out;
+
 			if (p->header.flag & BT_LEAF) {
 				/* uppercase leaf name to compare */
 				cmp =
-- 
2.37.2

Re: [PATCH-v2] jfs: fix slab-out-of-bounds Read in dtSearch

[Dave Kleikamp]

On 10/25/23 1:09AM, Manas Ghandat wrote:
> Currently while searching for current page in the sorted entry table
> of the page there is a out of bound access. Added a bound check to fix
> the error.

Looks good. I made the small change of setting rc = -EIO in that case, 
so we know there is something wrong with the file system.

Thanks,
Shaggy

> 
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> Closes: https://lore.kernel.org/r/202310241724.Ed02yUz9-lkp@intel.com/
> Signed-off-by: Manas Ghandat <ghandatmanas@gmail.com>
> ---
> V1 -> V2 : Removed redundant check on stbl
> 
>   fs/jfs/jfs_dtree.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/fs/jfs/jfs_dtree.c b/fs/jfs/jfs_dtree.c
> index 92b7c533407c..cf67d32d5b7f 100644
> --- a/fs/jfs/jfs_dtree.c
> +++ b/fs/jfs/jfs_dtree.c
> @@ -633,6 +633,9 @@ int dtSearch(struct inode *ip, struct component_name * key, ino_t * data,
>   		for (base = 0, lim = p->header.nextindex; lim; lim >>= 1) {
>   			index = base + (lim >> 1);
>   
> +			if (stbl[index] < 0)
> +				goto out;
> +
>   			if (p->header.flag & BT_LEAF) {
>   				/* uppercase leaf name to compare */
>   				cmp =