diff options
Diffstat (limited to 'fs/ext4/dir.c')
| -rw-r--r-- | fs/ext4/dir.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c index 17edd678fa87..8d7b81e6948e 100644 --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -138,6 +138,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx) struct buffer_head *bh = NULL; struct fscrypt_str fstr = FSTR_INIT(NULL, 0); struct dir_private_info *info = file->private_data; + bool has_csum = ext4_has_feature_metadata_csum(sb); err = fscrypt_prepare_readdir(inode); if (err) @@ -149,7 +150,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx) return err; /* Can we just clear INDEX flag to ignore htree information? */ - if (!ext4_has_feature_metadata_csum(sb)) { + if (!has_csum) { /* * We don't set the inode dirty flag since it's not * critical that it gets flushed back to the disk. @@ -235,7 +236,10 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx) * dirent right now. Scan from the start of the block * to make sure. */ if (!inode_eq_iversion(inode, info->cookie)) { - for (i = 0; i < sb->s_blocksize && i < offset; ) { + for (i = 0; + i <= sb->s_blocksize - + ext4_dir_rec_len(1, has_csum ? NULL : inode) && + i < offset;) { de = (struct ext4_dir_entry_2 *) (bh->b_data + i); /* It's too expensive to do a full @@ -257,6 +261,17 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx) info->cookie = inode_query_iversion(inode); } + if (unlikely(offset < sb->s_blocksize && + offset > sb->s_blocksize - + ext4_dir_rec_len(1, has_csum ? NULL : inode))) { + EXT4_ERROR_FILE(file, bh->b_blocknr, + "bad entry in directory: %s - offset=%u, size=%lu", + "directory entry too close to block end", + offset, sb->s_blocksize); + ctx->pos = round_up(ctx->pos, sb->s_blocksize); + goto next_block; + } + while (ctx->pos < inode->i_size && offset < sb->s_blocksize) { de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); @@ -312,6 +327,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx) ctx->pos += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); } +next_block: if ((ctx->pos < inode->i_size) && !dir_relax_shared(inode)) goto done; brelse(bh); |