2023-10-04 07:41:28

by Manas Ghandat

Subject: [PATCH v2] jfs: fix array-index-out-of-bounds in diAlloc

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: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=79d792676d8ac050949f
Signed-off-by: Manas Ghandat <[email protected]>
---
V1 -> V2 : Added check for higher bound of agno
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 799d3837e7c2..c0cf74e7392b 100644
--- a/fs/jfs/jfs_imap.c
+++ b/fs/jfs/jfs_imap.c
@@ -1319,7 +1319,7 @@ 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;
@@ -1355,6 +1355,9 @@ 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])) {
/*
--
2.37.2

2023-10-04 14:24:05

by Dave Kleikamp

Subject: Re: [PATCH v2] jfs: fix array-index-out-of-bounds in diAlloc

On 10/4/23 2:40AM, Manas Ghandat wrote:
> 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.

Applied to jfs-next

Thanks,
Shaggy

>
> Reported-by: [email protected]
> Closes: https://syzkaller.appspot.com/bug?extid=79d792676d8ac050949f
> Signed-off-by: Manas Ghandat <[email protected]>
> ---
> V1 -> V2 : Added check for higher bound of agno
> 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 799d3837e7c2..c0cf74e7392b 100644
> --- a/fs/jfs/jfs_imap.c
> +++ b/fs/jfs/jfs_imap.c
> @@ -1319,7 +1319,7 @@ 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;
> @@ -1355,6 +1355,9 @@ 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])) {
> /*