[PATCH 6.1 093/127] open: make RESOLVE_CACHED correctly test for O_TMPFILE

Greg Kroah-Hartman
2023-08-09T10:55:33Z

From: Aleksa Sarai <cyphar@cyphar.com>

commit a0fc452a5d7fed986205539259df1d60546f536c upstream.

O_TMPFILE is actually __O_TMPFILE|O_DIRECTORY. This means that the old
fast-path check for RESOLVE_CACHED would reject all users passing
O_DIRECTORY with -EAGAIN, when in fact the intended test was to check
for __O_TMPFILE.

Cc: stable@vger.kernel.org # v5.12+
Fixes: 99668f618062 ("fs: expose LOOKUP_CACHED through openat2() RESOLVE_CACHED")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Message-Id: <20230806-resolve_cached-o_tmpfile-v1-1-7ba16308465e@cyphar.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/open.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/open.c
+++ b/fs/open.c
@@ -1233,7 +1233,7 @@ inline int build_open_flags(const struct
lookup_flags |= LOOKUP_IN_ROOT;
if (how->resolve & RESOLVE_CACHED) {
/* Don't bother even trying for create/truncate/tmpfile open */
- if (flags & (O_TRUNC | O_CREAT | O_TMPFILE))
+ if (flags & (O_TRUNC | O_CREAT | __O_TMPFILE))
return -EAGAIN;
lookup_flags |= LOOKUP_CACHED;
}