This issue is found when creating /dev/sdtest with flags (O_CREAT |
O_DIRECT). The file still can be retrieved even after system reports
failure (-EINVAL) for it. Reporting error on creating the file is
correct behaviour because either devtmpfs or tmpfs doesn't support
O_DIRECT for regular file. However, it's incorrect that the file is
still existing. The cause is the newly allocated dentry and inode
aren't released on failure in do_last().
# rm /dev/sdtest
# dd if=/dev/urandom of=/dev/sdtest bs=4k count=1 oflag=direct
<-EINVAL is returned>
# ls /dev/sdtest
<File is still existing>
This fixes the issue by releasing the dentry, thus the inode on failure
in do_last(). With this applied, the file (/dev/sdtest) isn't seen
in this scenario.
Reported-by: YouYou <youyou.wy.huang@xxxxxxxxxxx>
Signed-off-by: Gavin Shan <dubo.sgw@xxxxxxxxxxxxxxx>
Signed-off-by: Liguang Zhang <liguang.zlg@xxxxxxxxxxxxxxx>
Signed-off-by: Ahao Mu <ahao.mah@xxxxxxxxxxxxxxx>
---
fs/namei.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/namei.c b/fs/namei.c
index 9cc91fb..607c357 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3382,6 +3382,8 @@ static int do_last(struct nameidata *nd,
*opened |= FILE_OPENED;
opened:
error = open_check_o_direct(file);
+ if (error && (*opened & FILE_OPENED))
+ dput(path.dentry);
if (!error)
error = ima_file_check(file, op->acc_mode, *opened);
if (!error && will_truncate)
--
1.8.3.1
