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ext4: Validate extent details only when read from the disk

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Make sure we validate extent details only when read from the disk.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Thiemo Nagel <thiemo.nagel@ph.tum.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Aneesh Kumar K.V
2009-03-27 16:39:58 -04:00
committed by Theodore Ts'o
parent 56b19868ac
commit 7a262f7c69
3 changed files with 29 additions and 7 deletions
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1
fs/ext4/ext4_extents.h
View File

@@ -241,5 +241,6 @@ extern int ext4_ext_search_left(struct inode *, struct ext4_ext_path *,
extern int ext4_ext_search_right(struct inode *, struct ext4_ext_path *, extern int ext4_ext_search_right(struct inode *, struct ext4_ext_path *,
ext4_lblk_t *, ext4_fsblk_t *); ext4_lblk_t *, ext4_fsblk_t *);
extern void ext4_ext_drop_refs(struct ext4_ext_path *); extern void ext4_ext_drop_refs(struct ext4_ext_path *);
extern int ext4_ext_check_inode(struct inode *inode);
#endif /* _EXT4_EXTENTS */ #endif /* _EXT4_EXTENTS */

25
fs/ext4/extents.c
View File

@@ -429,6 +429,11 @@ corrupted:
#define ext4_ext_check(inode, eh, depth) \ #define ext4_ext_check(inode, eh, depth) \
__ext4_ext_check(__func__, inode, eh, depth) __ext4_ext_check(__func__, inode, eh, depth)
int ext4_ext_check_inode(struct inode *inode)
{
return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
}
#ifdef EXT_DEBUG #ifdef EXT_DEBUG
static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
{ {
@@ -631,9 +636,6 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
eh = ext_inode_hdr(inode); eh = ext_inode_hdr(inode);
depth = ext_depth(inode); depth = ext_depth(inode);
if (ext4_ext_check(inode, eh, depth))
return ERR_PTR(-EIO);
/* account possible depth increase */ /* account possible depth increase */
if (!path) { if (!path) {
@@ -649,6 +651,8 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
i = depth; i = depth;
/* walk through the tree */ /* walk through the tree */
while (i) { while (i) {
int need_to_validate = 0;
ext_debug("depth %d: num %d, max %d\n", ext_debug("depth %d: num %d, max %d\n",
ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
@@ -657,10 +661,17 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
path[ppos].p_depth = i; path[ppos].p_depth = i;
path[ppos].p_ext = NULL; path[ppos].p_ext = NULL;
bh = sb_bread(inode->i_sb, path[ppos].p_block); bh = sb_getblk(inode->i_sb, path[ppos].p_block);
if (!bh) if (unlikely(!bh))
goto err; goto err;
if (!bh_uptodate_or_lock(bh)) {
if (bh_submit_read(bh) < 0) {
put_bh(bh);
goto err;
}
/* validate the extent entries */
need_to_validate = 1;
}
eh = ext_block_hdr(bh); eh = ext_block_hdr(bh);
ppos++; ppos++;
BUG_ON(ppos > depth); BUG_ON(ppos > depth);
@@ -668,7 +679,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
path[ppos].p_hdr = eh; path[ppos].p_hdr = eh;
i--; i--;
if (ext4_ext_check(inode, eh, i)) if (need_to_validate && ext4_ext_check(inode, eh, i))
goto err; goto err;
} }

10
fs/ext4/inode.c
View File

@@ -4345,6 +4345,16 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
(__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32; (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
} }
if (ei->i_flags & EXT4_EXTENTS_FL) {
/* Validate extent which is part of inode */
ret = ext4_ext_check_inode(inode);
if (ret) {
brelse(bh);
goto bad_inode;
}
}
if (S_ISREG(inode->i_mode)) { if (S_ISREG(inode->i_mode)) {
inode->i_op = &ext4_file_inode_operations; inode->i_op = &ext4_file_inode_operations;
inode->i_fop = &ext4_file_operations; inode->i_fop = &ext4_file_operations;