[PATCH 4.14 163/191] udf: Avoid accessing uninitialized data on failed inode read

Greg Kroah-Hartman
2020-10-27T14:18:40Z

From: Jan Kara <jack@suse.cz>

[ Upstream commit 044e2e26f214e5ab26af85faffd8d1e4ec066931 ]

When we fail to read inode, some data accessed in udf_evict_inode() may
be uninitialized. Move the accesses to !is_bad_inode() branch.

Reported-by: syzbot+91f02b28f9bb5f5f1341@syzkaller.appspotmail.com
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/udf/inode.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 3c1b54091d6cc..dd57bd446340c 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -132,21 +132,24 @@ void udf_evict_inode(struct inode *inode)
struct udf_inode_info *iinfo = UDF_I(inode);
int want_delete = 0;

- if (!inode->i_nlink && !is_bad_inode(inode)) {
- want_delete = 1;
- udf_setsize(inode, 0);
- udf_update_inode(inode, IS_SYNC(inode));
+ if (!is_bad_inode(inode)) {
+ if (!inode->i_nlink) {
+ want_delete = 1;
+ udf_setsize(inode, 0);
+ udf_update_inode(inode, IS_SYNC(inode));
+ }
+ if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB &&
+ inode->i_size != iinfo->i_lenExtents) {
+ udf_warn(inode->i_sb,
+ "Inode %lu (mode %o) has inode size %llu different from extent length %llu. Filesystem need not be standards compliant.\n",
+ inode->i_ino, inode->i_mode,
+ (unsigned long long)inode->i_size,
+ (unsigned long long)iinfo->i_lenExtents);
+ }
}
truncate_inode_pages_final(&inode->i_data);
invalidate_inode_buffers(inode);
clear_inode(inode);
- if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB &&
- inode->i_size != iinfo->i_lenExtents) {
- udf_warn(inode->i_sb, "Inode %lu (mode %o) has inode size %llu different from extent length %llu. Filesystem need not be standards compliant.\n",
- inode->i_ino, inode->i_mode,
- (unsigned long long)inode->i_size,
- (unsigned long long)iinfo->i_lenExtents);
- }
kfree(iinfo->i_ext.i_data);
iinfo->i_ext.i_data = NULL;
udf_clear_extent_cache(inode);
--
2.25.1