2023-09-26 13:27:49

by Manas Ghandat

Subject: [PATCH] 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.

Signed-off-by: Manas Ghandat <[email protected]>
---
fs/jfs/jfs_imap.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c
index 799d3837e7c2..ace8a1506380 100644
--- a/fs/jfs/jfs_imap.c
+++ b/fs/jfs/jfs_imap.c
@@ -1355,6 +1355,8 @@ 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));
+ if (agno < 0)
+ return -EIO;

if (atomic_read(&JFS_SBI(pip->i_sb)->bmap->db_active[agno])) {
/*
--
2.37.2

2023-10-02 07:41:09

by Manas Ghandat

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

just a friendly ping

On 26/09/23 12:43, 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.
>
> Signed-off-by: Manas Ghandat <[email protected]>
> ---
> fs/jfs/jfs_imap.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c
> index 799d3837e7c2..ace8a1506380 100644
> --- a/fs/jfs/jfs_imap.c
> +++ b/fs/jfs/jfs_imap.c
> @@ -1355,6 +1355,8 @@ 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));
> + if (agno < 0)
> + return -EIO;
>
> if (atomic_read(&JFS_SBI(pip->i_sb)->bmap->db_active[agno])) {
> /*

2023-10-03 23:23:06

by Dave Kleikamp

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

On 9/26/23 2:13AM, 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.

Does this fix an observed problem? It seems reasonable and if we add
this we may also want to make sure that agno doesn't exceed db_numag,
(JFS_SBI(pip->i_sb)->bmap->db_numag) (yuck).

>
> Signed-off-by: Manas Ghandat <[email protected]>
> ---
> fs/jfs/jfs_imap.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c
> index 799d3837e7c2..ace8a1506380 100644
> --- a/fs/jfs/jfs_imap.c
> +++ b/fs/jfs/jfs_imap.c
> @@ -1355,6 +1355,8 @@ 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));
> + if (agno < 0)
> + return -EIO;
>
> if (atomic_read(&JFS_SBI(pip->i_sb)->bmap->db_active[agno])) {
> /*