[PATCH 5.7 177/204] fs/minix: fix block limit check for V1 filesystems

Greg Kroah-Hartman
2020-08-20T12:55:57Z

From: Eric Biggers <ebiggers@google.com>

[ Upstream commit 0a12c4a8069607247cb8edc3b035a664e636fd9a ]

The minix filesystem reads its maximum file size from its on-disk
superblock. This value isn't necessarily a multiple of the block size.
When it's not, the V1 block mapping code doesn't allow mapping the last
possible block. Commit 6ed6a722f9ab ("minixfs: fix block limit check")
fixed this in the V2 mapping code. Fix it in the V1 mapping code too.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Qiujun Huang <anenbupt@gmail.com>
Link: http://lkml.kernel.org/r/20200628060846.682158-6-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/minix/itree_v1.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/minix/itree_v1.c b/fs/minix/itree_v1.c
index c0d418209ead1..405573a79aab4 100644
--- a/fs/minix/itree_v1.c
+++ b/fs/minix/itree_v1.c
@@ -29,7 +29,7 @@ static int block_to_path(struct inode * inode, long block, int offsets[DEPTH])
if (block < 0) {
printk("MINIX-fs: block_to_path: block %ld < 0 on dev %pg\n",
block, inode->i_sb->s_bdev);
- } else if (block >= inode->i_sb->s_maxbytes/BLOCK_SIZE) {
+ } else if ((u64)block * BLOCK_SIZE >= inode->i_sb->s_maxbytes) {
if (printk_ratelimit())
printk("MINIX-fs: block_to_path: "
"block %ld too big on dev %pg\n",
--
2.25.1