This is a note to let you know that I've just added the patch titled
fs/jfs: fix shift exponent db_agl2size negative
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fs-jfs-fix-shift-exponent-db_agl2size-negative.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a042f3c7ffffbde38065115517f676fcb6833970
Author: Liu Shixin via Jfs-discussion <jfs-discussion@xxxxxxxxxxxxxxxxxxxxx>
Date: Thu Nov 3 11:01:59 2022 +0800
fs/jfs: fix shift exponent db_agl2size negative
[ Upstream commit fad376fce0af58deebc5075b8539dc05bf639af3 ]
As a shift exponent, db_agl2size can not be less than 0. Add the missing
check to fix the shift-out-of-bounds bug reported by syzkaller:
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:2227:15
shift exponent -744642816 is negative
Reported-by: syzbot+0be96567042453c0c820@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Liu Shixin <liushixin2@xxxxxxxxxx>
Signed-off-by: Dave Kleikamp <dave.kleikamp@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 0ca1ad2610df9..6a0f564e58ddb 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -206,7 +206,8 @@ int dbMount(struct inode *ipbmap)
bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth);
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) {
+ if (bmp->db_agl2size > L2MAXL2SIZE - L2MAXAG ||
+ bmp->db_agl2size < 0) {
err = -EINVAL;
goto err_release_metapage;
}
