From: Zhang Yi
maillist inclusion
category: bugfix
issue: #I4NRS5
CVE: NA
Signed-off-by: Yu Changchun
---------------------------
In ext4_get_inode_loc(), we may skip IO and get an zero && uptodate
inode buffer when the inode monopolize an inode block for performance
reason. For most cases, ext4_mark_iloc_dirty() will fill the inode
buffer to make it fine, but we could miss this call if something bad
happened. Finally, __ext4_get_inode_loc_noinmem() may probably get an
empty inode buffer and trigger ext4 error.
For example, if we remove a nonexistent xattr on inode A,
ext4_xattr_set_handle() will return ENODATA before invoking
ext4_mark_iloc_dirty(), it will left an uptodate but zero buffer. We
will get checksum error message in ext4_iget() when getting inode again.
EXT4-fs error (device sda): ext4_lookup:1784: inode #131074: comm cat: iget: checksum invalid
Even worse, if we allocate another inode B at the same inode block, it
will corrupt the inode A on disk when write back inode B.
So this patch initialize the inode buffer by filling the in-mem inode
contents if we skip read I/O, ensure that the buffer is really uptodate.
Signed-off-by: Zhang Yi
Reviewed-by: Yang Erkun
Signed-off-by: Chen Jun
Signed-off-by: Zheng Zengkai
Signed-off-by: Yu Changchun
---
fs/ext4/inode.c | 24 ++++++++++++++----------
1 file changed, 14 insertions(+), 10 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 1eefbc464964..16bc65609496 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4452,12 +4452,12 @@ static int ext4_fill_raw_inode(struct inode *inode, struct ext4_inode *raw_inode
/*
* ext4_get_inode_loc returns with an extra refcount against the inode's
- * underlying buffer_head on success. If 'in_mem' is true, we have all
- * data in memory that is needed to recreate the on-disk version of this
- * inode.
+ * underlying buffer_head on success. If we pass 'inode' and it does not
+ * have in-inode xattr, we have all inode data in memory that is needed
+ * to recreate the on-disk version of this inode.
*/
static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino,
- struct ext4_iloc *iloc, int in_mem,
+ struct inode *inode, struct ext4_iloc *iloc,
ext4_fsblk_t *ret_block)
{
struct ext4_group_desc *gdp;
@@ -4502,7 +4502,7 @@ static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino,
* is the only valid inode in the block, we need not read the
* block.
*/
- if (in_mem) {
+ if (inode && !ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
struct buffer_head *bitmap_bh;
int i, start;
@@ -4530,8 +4530,13 @@ static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino,
}
brelse(bitmap_bh);
if (i == start + inodes_per_block) {
+ struct ext4_inode *raw_inode =
+ (struct ext4_inode *) (bh->b_data + iloc->offset);
+
/* all other inodes are free, so skip I/O */
memset(bh->b_data, 0, bh->b_size);
+ if (!ext4_test_inode_state(inode, EXT4_STATE_NEW))
+ ext4_fill_raw_inode(inode, raw_inode);
set_buffer_uptodate(bh);
unlock_buffer(bh);
goto has_buffer;
@@ -4593,7 +4598,7 @@ static int __ext4_get_inode_loc_noinmem(struct inode *inode,
ext4_fsblk_t err_blk;
int ret;
- ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, iloc, 0,
+ ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, NULL, iloc,
&err_blk);
if (ret == -EIO)
@@ -4608,9 +4613,8 @@ int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
ext4_fsblk_t err_blk;
int ret;
- /* We have all inode data except xattrs in memory here. */
- ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, iloc,
- !ext4_test_inode_state(inode, EXT4_STATE_XATTR), &err_blk);
+ ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, inode, iloc,
+ &err_blk);
if (ret == -EIO)
ext4_error_inode_block(inode, err_blk, EIO,
@@ -4623,7 +4627,7 @@ int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
int ext4_get_fc_inode_loc(struct super_block *sb, unsigned long ino,
struct ext4_iloc *iloc)
{
- return __ext4_get_inode_loc(sb, ino, iloc, 0, NULL);
+ return __ext4_get_inode_loc(sb, ino, NULL, iloc, NULL);
}
static bool ext4_should_enable_dax(struct inode *inode)
--
2.25.1
