open: make RESOLVE_CACHED correctly test for O_TMPFILE
authorAleksa Sarai <cyphar@cyphar.com>
Sat, 5 Aug 2023 16:11:58 +0000 (02:11 +1000)
committerChristian Brauner <brauner@kernel.org>
Sun, 6 Aug 2023 13:08:35 +0000 (15:08 +0200)
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>
fs/open.c

index 0c55c8e7f837d8ef03ab19b5645b40401205ee42..e6ead0f19964957afd601cb4f7ad1ab88a9a510c 100644 (file)
--- a/fs/open.c
+++ b/fs/open.c
@@ -1322,7 +1322,7 @@ inline int build_open_flags(const struct open_how *how, struct open_flags *op)
                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;
        }