[PATCH] vfs: fix linkat error for unprivileged AT_EMPTY_PATH

From: Miklos Szeredi
Date: Wed Sep 24 2014 - 11:25:33 EST


From: Miklos Szeredi <mszeredi@xxxxxxx>

Return proper error value for linkat(..., AT_EMPTY_PATH) without enough
privileges.

I guess ENOENT was used here, because without AT_EMPTY_PATH that's what
we'd return for an empty path. But it is wrong for AT_EMPTY_PATH, since we
might not even be passing an empty path, we are simply complaining about
lack of privs for which EPERM is the proper error.

Fixes: 11a7b371b64e ("fs: allow AT_EMPTY_PATH in linkat()...")
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 2.6.39+
---
fs/namei.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3957,7 +3957,7 @@ SYSCALL_DEFINE5(linkat, int, olddfd, con
*/
if (flags & AT_EMPTY_PATH) {
if (!capable(CAP_DAC_READ_SEARCH))
- return -ENOENT;
+ return -EPERM;
how = LOOKUP_EMPTY;
}

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