[v1] jfs: fix array-index-out-of-bounds in diAlloc

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

Posted by Manas Ghandat 2 years, 4 months ago

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 <ghandatmanas@gmail.com>
---
 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

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

Posted by Dave Kleikamp 2 years, 4 months ago

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 <ghandatmanas@gmail.com>
> ---
>   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])) {
>   		/*

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

Posted by Manas Ghandat 2 years, 4 months ago

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 <ghandatmanas@gmail.com>
> ---
>   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])) {
>   		/*