From 9bb1d7a6bcde2e45ecb29967b77e6716e155c252 Mon Sep 17 00:00:00 2001 From: Chengguang Xu Date: Tue, 28 May 2019 10:59:45 +0800 Subject: ext2: merge xattr next entry check to ext2_xattr_entry_valid() We have introduced ext2_xattr_entry_valid() for xattr entry sanity check, so it's better to do relevant things in one place. Signed-off-by: Chengguang Xu Signed-off-by: Jan Kara --- fs/ext2/xattr.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-) (limited to 'fs/ext2') diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c index d21dbf297b74..28503979696d 100644 --- a/fs/ext2/xattr.c +++ b/fs/ext2/xattr.c @@ -145,10 +145,16 @@ ext2_xattr_header_valid(struct ext2_xattr_header *header) } static bool -ext2_xattr_entry_valid(struct ext2_xattr_entry *entry, size_t end_offs) +ext2_xattr_entry_valid(struct ext2_xattr_entry *entry, + char *end, size_t end_offs) { + struct ext2_xattr_entry *next; size_t size; + next = EXT2_XATTR_NEXT(entry); + if ((char *)next >= end) + return false; + if (entry->e_value_block != 0) return false; @@ -214,17 +220,14 @@ bad_block: /* find named attribute */ entry = FIRST_ENTRY(bh); while (!IS_LAST_ENTRY(entry)) { - struct ext2_xattr_entry *next = - EXT2_XATTR_NEXT(entry); - if ((char *)next >= end) - goto bad_block; - if (!ext2_xattr_entry_valid(entry, inode->i_sb->s_blocksize)) + if (!ext2_xattr_entry_valid(entry, end, + inode->i_sb->s_blocksize)) goto bad_block; if (name_index == entry->e_name_index && name_len == entry->e_name_len && memcmp(name, entry->e_name, name_len) == 0) goto found; - entry = next; + entry = EXT2_XATTR_NEXT(entry); } if (ext2_xattr_cache_insert(ea_block_cache, bh)) ea_idebug(inode, "cache insert failed"); @@ -299,13 +302,10 @@ bad_block: /* check the on-disk data structure */ entry = FIRST_ENTRY(bh); while (!IS_LAST_ENTRY(entry)) { - struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(entry); - - if ((char *)next >= end) - goto bad_block; - if (!ext2_xattr_entry_valid(entry, inode->i_sb->s_blocksize)) + if (!ext2_xattr_entry_valid(entry, end, + inode->i_sb->s_blocksize)) goto bad_block; - entry = next; + entry = EXT2_XATTR_NEXT(entry); } if (ext2_xattr_cache_insert(ea_block_cache, bh)) ea_idebug(inode, "cache insert failed"); @@ -390,7 +390,7 @@ ext2_xattr_set(struct inode *inode, int name_index, const char *name, struct super_block *sb = inode->i_sb; struct buffer_head *bh = NULL; struct ext2_xattr_header *header = NULL; - struct ext2_xattr_entry *here, *last; + struct ext2_xattr_entry *here = NULL, *last = NULL; size_t name_len, free, min_offs = sb->s_blocksize; int not_found = 1, error; char *end; @@ -444,10 +444,7 @@ bad_block: */ last = FIRST_ENTRY(bh); while (!IS_LAST_ENTRY(last)) { - struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(last); - if ((char *)next >= end) - goto bad_block; - if (!ext2_xattr_entry_valid(last, sb->s_blocksize)) + if (!ext2_xattr_entry_valid(last, end, sb->s_blocksize)) goto bad_block; if (last->e_value_size) { size_t offs = le16_to_cpu(last->e_value_offs); @@ -465,7 +462,7 @@ bad_block: if (not_found <= 0) here = last; } - last = next; + last = EXT2_XATTR_NEXT(last); } if (not_found > 0) here = last; @@ -476,7 +473,6 @@ bad_block: /* We will use a new extended attribute block. */ free = sb->s_blocksize - sizeof(struct ext2_xattr_header) - sizeof(__u32); - here = last = NULL; /* avoid gcc uninitialized warning. */ } if (not_found) { -- cgit