This is a note to let you know that I've just added the patch titled
jfs: Fix shift-out-of-bounds in dbDiscardAG
to the 6.10-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:
jfs-fix-shift-out-of-bounds-in-dbdiscardag.patch
and it can be found in the queue-6.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3c75936d660549f159306ab0b06ede433bb4ad7f
Author: Pei Li <peili.dev@xxxxxxxxx>
Date: Tue Jun 25 09:42:05 2024 -0700
jfs: Fix shift-out-of-bounds in dbDiscardAG
[ Upstream commit 7063b80268e2593e58bee8a8d709c2f3ff93e2f2 ]
When searching for the next smaller log2 block, BLKSTOL2() returned 0,
causing shift exponent -1 to be negative.
This patch fixes the issue by exiting the loop directly when negative
shift is found.
Reported-by: syzbot+61be3359d2ee3467e7e4@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=61be3359d2ee3467e7e4
Signed-off-by: Pei Li <peili.dev@xxxxxxxxx>
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 cb3cda1390adb..5713994328cbc 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -1626,6 +1626,8 @@ s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen)
} else if (rc == -ENOSPC) {
/* search for next smaller log2 block */
l2nb = BLKSTOL2(nblocks) - 1;
+ if (unlikely(l2nb < 0))
+ break;
nblocks = 1LL << l2nb;
} else {
/* Trim any already allocated blocks */
