fs/sysv: v7: adjust sanity checks for some volumes

Newly mkfs-ed filesystems from Seventh Edition have last modification time
set to zero, but are otherwise perfectly valid.

Also, tighten up other sanity checks to filter out most filesystems with

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/sysv/super.c b/fs/sysv/super.c
index 2da3075aff78..3785262b98e0 100644
--- a/fs/sysv/super.c
+++ b/fs/sysv/super.c
@@ -469,7 +469,7 @@ static int v7_fill_super(struct super_block *sb, void *data, int silent)
         v7sb = (struct v7_super_block *) bh->b_data;
         if (fs16_to_cpu(sbi, v7sb->s_nfree) > V7_NICFREE ||
             fs16_to_cpu(sbi, v7sb->s_ninode) > V7_NICINOD ||
-            fs32_to_cpu(sbi, v7sb->s_time) == 0)
+            fs32_to_cpu(sbi, v7sb->s_fsize) > V7_MAXSIZE)
                 goto failed;
 
         /* plausibility check on root inode: it is a directory,
@@ -479,7 +479,9 @@ static int v7_fill_super(struct super_block *sb, void *data, int silent)
         v7i = (struct sysv_inode *)(bh2->b_data + 64);
         if ((fs16_to_cpu(sbi, v7i->i_mode) & ~0777) != S_IFDIR ||
             (fs32_to_cpu(sbi, v7i->i_size) == 0) ||
-            (fs32_to_cpu(sbi, v7i->i_size) & 017) != 0)
+            (fs32_to_cpu(sbi, v7i->i_size) & 017) ||
+            (fs32_to_cpu(sbi, v7i->i_size) > V7_NFILES *
+             sizeof(struct sysv_dir_entry)))
                 goto failed;
         brelse(bh2);
         bh2 = NULL;