[PATCH v2 1/2] open: make RESOLVE_CACHED correctly test for O_TMPFILE

From: Aleksa Sarai
Date: Sat Aug 05 2023 - 18:49:01 EST


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@xxxxxxxxxxxxxxx # v5.12+
Fixes: 99668f618062 ("fs: expose LOOKUP_CACHED through openat2() RESOLVE_CACHED")
Signed-off-by: Aleksa Sarai <cyphar@xxxxxxxxxx>
---
fs/open.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/open.c b/fs/open.c
index b8883ec286f5..2634047c9e9f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1337,7 +1337,7 @@ 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;
}

--
2.41.0