From 7a262f7c69163cd4811f2f838faef5c5b18439c9 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Fri, 27 Mar 2009 16:39:58 -0400 Subject: [PATCH] ext4: Validate extent details only when read from the disk Make sure we validate extent details only when read from the disk. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Thiemo Nagel Signed-off-by: "Theodore Ts'o" --- fs/ext4/ext4_extents.h | 1 + fs/ext4/extents.c | 25 ++++++++++++++++++------- fs/ext4/inode.c | 10 ++++++++++ 3 files changed, 29 insertions(+), 7 deletions(-) diff --git a/fs/ext4/ext4_extents.h b/fs/ext4/ext4_extents.h index 18cb67b2cbb..f0c3ec85bd4 100644 --- a/fs/ext4/ext4_extents.h +++ b/fs/ext4/ext4_extents.h @@ -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 *, ext4_lblk_t *, ext4_fsblk_t *); extern void ext4_ext_drop_refs(struct ext4_ext_path *); +extern int ext4_ext_check_inode(struct inode *inode); #endif /* _EXT4_EXTENTS */ diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index ee40b7c52c8..ac77d8b8251 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -429,6 +429,11 @@ corrupted: #define ext4_ext_check(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 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); depth = ext_depth(inode); - if (ext4_ext_check(inode, eh, depth)) - return ERR_PTR(-EIO); - /* account possible depth increase */ if (!path) { @@ -649,6 +651,8 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, i = depth; /* walk through the tree */ while (i) { + int need_to_validate = 0; + ext_debug("depth %d: num %d, max %d\n", 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_ext = NULL; - bh = sb_bread(inode->i_sb, path[ppos].p_block); - if (!bh) + bh = sb_getblk(inode->i_sb, path[ppos].p_block); + if (unlikely(!bh)) 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); ppos++; BUG_ON(ppos > depth); @@ -668,7 +679,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, path[ppos].p_hdr = eh; i--; - if (ext4_ext_check(inode, eh, i)) + if (need_to_validate && ext4_ext_check(inode, eh, i)) goto err; } diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 25811507d2b..cd0399db0ef 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -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; } + 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)) { inode->i_op = &ext4_file_inode_operations; inode->i_fop = &ext4_file_operations; -- 2.41.1