On 2/20/25 5:24AM, Edward Adam Davis wrote:
The width in dmapctl of the AG is zero, it trigger a divide error when calculating the control page level in dbAllocAG. To avoid this issue, add a check for agwidth in dbAllocAG.
Looks good. Will add this to jfs-next. Thanks, Shaggy
Reported-and-tested-by: syzbot+7c808908291a569281a9@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=7c808908291a569281a9 Signed-off-by: Edward Adam Davis <eadavis@xxxxxx> --- V1 -> V2: move the check to dbMount fs/jfs/jfs_dmap.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index f9009e4f9ffd..62f55e7ed840 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -204,6 +204,10 @@ int dbMount(struct inode *ipbmap) bmp->db_aglevel = le32_to_cpu(dbmp_le->dn_aglevel); bmp->db_agheight = le32_to_cpu(dbmp_le->dn_agheight); bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth); + if (!bmp->db_agwidth) { + err = -EINVAL; + goto err_release_metapage; + } bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart); bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size); if (bmp->db_agl2size > L2MAXL2SIZE - L2MAXAG ||
