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authorRakesh Pandit <rakesh@tuxera.com>2017-07-13 00:34:07 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-13 02:26:00 +0300
commit5f9f48f5b385457426b4b8f3f4a604019a8e7350 (patch)
tree5432ea87aa90b672f12766e5c5f245d5edc00cd0 /fs/bfs
parentee7998c50c2697737c6530431709f77c852bf0d6 (diff)
downloadlinux-5f9f48f5b385457426b4b8f3f4a604019a8e7350.tar.xz
bfs: fix sanity checks for empty files
Mount fails if file system image has empty files because of sanity check while reading superblock. For empty files disk offset to end of file (i_eoffset) is cpu_to_le32(-1). Sanity check comparison, which compares disk offset with file system size isn't valid for this value and hence is ignored with this patch. Steps to reproduce: $ dd if=/dev/zero of=bfs-image count=204800 $ mkfs.bfs bfs-image $ mkdir bfs-mount-point $ sudo mount -t bfs -o loop bfs-image bfs-mount-point/ $ cd bfs-mount-point/ $ sudo touch a $ cd .. $ sudo umount bfs-mount-point/ $ sudo mount -t bfs -o loop bfs-image bfs-mount-point/ mount: /dev/loop0: can't read superblock $ dmesg [25526.689580] BFS-fs: bfs_fill_super(): Inode 0x00000003 corrupted Tigran said: "If you had created the filesystem with the proper mkfs under SCO UnixWare 7 you (probably) wouldn't encounter this issue. But since commercial Unix-es are now part of history and the only proper way is the Linux mkfs.bfs utility, your patch is fine" Link: http://lkml.kernel.org/r/20170505201625.GA3097@hercules.tuxera.com Signed-off-by: Rakesh Pandit <rakesh@tuxera.com> Acked-by: Tigran Aivazian <aivazian.tigran@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/bfs')
-rw-r--r--fs/bfs/inode.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/bfs/inode.c b/fs/bfs/inode.c
index 25e312cb6071..9a69392f1fb3 100644
--- a/fs/bfs/inode.c
+++ b/fs/bfs/inode.c
@@ -419,7 +419,7 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent)
if (i_sblock > info->si_blocks ||
i_eblock > info->si_blocks ||
i_sblock > i_eblock ||
- i_eoff > s_size ||
+ (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
i_sblock * BFS_BSIZE > i_eoff) {
printf("Inode 0x%08x corrupted\n", i);