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authorDarrick J. Wong <darrick.wong@oracle.com>2014-07-28 21:06:26 +0400
committerTheodore Ts'o <tytso@mit.edu>2014-07-28 21:06:26 +0400
commit40b163f1c45f52752677e66d2fd273dbfd273a22 (patch)
tree9047b84d0ab4086388c351d2f49e3ed1fba576d0 /fs/ext4/dir.c
parent6e2631463f3a2ce430a295c68aead3ff228ca3cf (diff)
downloadlinux-40b163f1c45f52752677e66d2fd273dbfd273a22.tar.xz
ext4: check inline directory before converting
Before converting an inline directory to a regular directory, check the directory entries to make sure they're not obviously broken. This helps us to avoid a BUG_ON if one of the dirents is trashed. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Diffstat (limited to 'fs/ext4/dir.c')
-rw-r--r--fs/ext4/dir.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index ef1bed66c14f..0bb3f9ea0832 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -571,6 +571,31 @@ static int ext4_release_dir(struct inode *inode, struct file *filp)
return 0;
}
+int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf,
+ int buf_size)
+{
+ struct ext4_dir_entry_2 *de;
+ int nlen, rlen;
+ unsigned int offset = 0;
+ char *top;
+
+ de = (struct ext4_dir_entry_2 *)buf;
+ top = buf + buf_size;
+ while ((char *) de < top) {
+ if (ext4_check_dir_entry(dir, NULL, de, bh,
+ buf, buf_size, offset))
+ return -EIO;
+ nlen = EXT4_DIR_REC_LEN(de->name_len);
+ rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
+ de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
+ offset += rlen;
+ }
+ if ((char *) de > top)
+ return -EIO;
+
+ return 0;
+}
+
const struct file_operations ext4_dir_operations = {
.llseek = ext4_dir_llseek,
.read = generic_read_dir,