open: make RESOLVE_CACHED correctly test for O_TMPFILE

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>

diff --git a/fs/open.c b/fs/open.c
index e93c33069055b1d9a7d7db2cabc584537e50e8e0..159a2765b7eb2c7caa22fd57624e4348f7f2620c 100644 (file)
--- a/fs/open.c
+++ b/fs/open.c
@@ -1126,7 +1126,7 @@ 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;
        }