On 8/15/24 8:25AM, Greg Kroah-Hartman wrote:
6.6-stable review patch. If anyone has any objections, please let me know.
Please do not include this patch and its revert (62/67). This was not a
good fix.
Thanks,
Shaggy
------------------
From: Manas Ghandat <ghandatmanas@xxxxxxxxx>
[ Upstream commit cca974daeb6c43ea971f8ceff5a7080d7d49ee30 ]
Currently while joining the leaf in a buddy system there is shift out
of bound error in calculation of BUDSIZE. Added the required check
to the BUDSIZE and fixed the documentation as well.
Reported-by: syzbot+411debe54d318eaed386@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=411debe54d318eaed386
Signed-off-by: Manas Ghandat <ghandatmanas@xxxxxxxxx>
Signed-off-by: Dave Kleikamp <dave.kleikamp@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/jfs/jfs_dmap.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index cb3cda1390adb..8eec84c651bfb 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -2763,7 +2763,9 @@ static int dbBackSplit(dmtree_t *tp, int leafno, bool is_ctl)
* leafno - the number of the leaf to be updated.
* newval - the new value for the leaf.
*
- * RETURN VALUES: none
+ * RETURN VALUES:
+ * 0 - success
+ * -EIO - i/o error
*/
static int dbJoin(dmtree_t *tp, int leafno, int newval, bool is_ctl)
{
@@ -2790,6 +2792,10 @@ static int dbJoin(dmtree_t *tp, int leafno, int newval, bool is_ctl)
* get the buddy size (number of words covered) of
* the new value.
*/
+
+ if ((newval - tp->dmt_budmin) > BUDMIN)
+ return -EIO;
+
budsz = BUDSIZE(newval, tp->dmt_budmin);
/* try to join.
