diff options
| author | OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> | 2020-06-04 16:50:56 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-06-20 10:23:19 +0200 |
| commit | 3a5e7e46bdada447e60a707fe3d5d853befcfd31 (patch) | |
| tree | 3616bb831c97a9114303d47bfc017d90657b1e81 | |
| parent | bc1ca055244a0268501017f1a7fe54529ca0e82c (diff) | |
fat: don't allow to mount if the FAT length == 0
commit b1b65750b8db67834482f758fc385bfa7560d228 upstream.
If FAT length == 0, the image doesn't have any data. And it can be the
cause of overlapping the root dir and FAT entries.
Also Windows treats it as invalid format.
Reported-by: syzbot+6f1624f937d9d6911e2d@syzkaller.appspotmail.com
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Link: http://lkml.kernel.org/r/87r1wz8mrd.fsf@mail.parknet.co.jp
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/fat/inode.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 5e87b9aa7ba6..944fff1ef536 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -1422,6 +1422,12 @@ static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, goto out; } + if (bpb->fat_fat_length == 0 && bpb->fat32_length == 0) { + if (!silent) + fat_msg(sb, KERN_ERR, "bogus number of FAT sectors"); + goto out; + } + error = 0; out: |