[PATCH AUTOSEL 6.5 13/34] jfs: fix array-index-out-of-bounds in diAlloc

Sasha Levin
2023-11-07T15:52:44Z

From: Manas Ghandat <ghandatmanas@gmail.com>

[ Upstream commit 05d9ea1ceb62a55af6727a69269a4fd310edf483 ]

Currently there is not check against the agno of the iag while
allocating new inodes to avoid fragmentation problem. Added the check
which is required.

Reported-by: syzbot+79d792676d8ac050949f@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=79d792676d8ac050949f
Signed-off-by: Manas Ghandat <ghandatmanas@gmail.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/jfs/jfs_imap.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c
index 6fb28572cb2c6..34f1358264e23 100644
--- a/fs/jfs/jfs_imap.c
+++ b/fs/jfs/jfs_imap.c
@@ -1320,7 +1320,7 @@ diInitInode(struct inode *ip, int iagno, int ino, int extno, struct iag * iagp)
int diAlloc(struct inode *pip, bool dir, struct inode *ip)
{
int rc, ino, iagno, addext, extno, bitno, sword;
- int nwords, rem, i, agno;
+ int nwords, rem, i, agno, dn_numag;
u32 mask, inosmap, extsmap;
struct inode *ipimap;
struct metapage *mp;
@@ -1356,6 +1356,9 @@ int diAlloc(struct inode *pip, bool dir, struct inode *ip)

/* get the ag number of this iag */
agno = BLKTOAG(JFS_IP(pip)->agstart, JFS_SBI(pip->i_sb));
+ dn_numag = JFS_SBI(pip->i_sb)->bmap->db_numag;
+ if (agno < 0 || agno > dn_numag)
+ return -EIO;

if (atomic_read(&JFS_SBI(pip->i_sb)->bmap->db_active[agno])) {
/*
--
2.42.0