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-rw-r--r--fs/minix/inode.c22
1 files changed, 20 insertions, 2 deletions
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index 2bca95abe8f4..0dd929346f3f 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -150,6 +150,23 @@ static int minix_remount (struct super_block * sb, int * flags, char * data)
return 0;
}
+static bool minix_check_superblock(struct minix_sb_info *sbi)
+{
+ if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0)
+ return false;
+
+ /*
+ * s_max_size must not exceed the block mapping limitation. This check
+ * is only needed for V1 filesystems, since V2/V3 support an extra level
+ * of indirect blocks which places the limit well above U32_MAX.
+ */
+ if (sbi->s_version == MINIX_V1 &&
+ sbi->s_max_size > (7 + 512 + 512*512) * BLOCK_SIZE)
+ return false;
+
+ return true;
+}
+
static int minix_fill_super(struct super_block *s, void *data, int silent)
{
struct buffer_head *bh;
@@ -228,11 +245,12 @@ static int minix_fill_super(struct super_block *s, void *data, int silent)
} else
goto out_no_fs;
+ if (!minix_check_superblock(sbi))
+ goto out_illegal_sb;
+
/*
* Allocate the buffer map to keep the superblock small.
*/
- if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0)
- goto out_illegal_sb;
i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
map = kzalloc(i, GFP_KERNEL);
if (!map)