diff options
| -rw-r--r-- | fs/sysv/super.c | 6 | ||||
| -rw-r--r-- | include/linux/sysv_fs.h | 11 |
2 files changed, 15 insertions, 2 deletions
diff --git a/fs/sysv/super.c b/fs/sysv/super.c index 2da3075aff7..3785262b98e 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; diff --git a/include/linux/sysv_fs.h b/include/linux/sysv_fs.h index 96411306eec..e47d6d90023 100644 --- a/include/linux/sysv_fs.h +++ b/include/linux/sysv_fs.h @@ -148,6 +148,17 @@ struct v7_super_block { char s_fname[6]; /* file system name */ char s_fpack[6]; /* file system pack name */ }; +/* Constants to aid sanity checking */ +/* This is not a hard limit, nor enforced by v7 kernel. It's actually just + * the limit used by Seventh Edition's ls, though is high enough to assume + * that no reasonable file system would have that much entries in root + * directory. Thus, if we see anything higher, we just probably got the + * endiannes wrong. */ +#define V7_NFILES 1024 +/* The disk addresses are three-byte (despite direct block addresses being + * aligned word-wise in inode). If the most significant byte is non-zero, + * something is most likely wrong (not a filesystem, bad bytesex). */ +#define V7_MAXSIZE 0x00ffffff /* Coherent super-block data on disk */ #define COH_NICINOD 100 /* number of inode cache entries */ |