[PATCH v2 1/2] erofs-utils: fuse: add missing return on getattr error

[Ajay Rajera]

erofsfuse_getattr() calls fuse_reply_err() when erofs_read_inode_from_disk()
fails, but does not return afterwards. This causes the function to fall through
to erofsfuse_fill_stat() with uninitialized inode data and then call
fuse_reply_attr(), sending a second reply to the same FUSE request.

Sending two replies to a single FUSE request is undefined behavior in libfuse
and typically triggers an assertion failure or crash. The uninitialized inode
data may also expose garbage values to userspace.

Fix by adding the missing return after fuse_reply_err().

Signed-off-by: Ajay Rajera <newajay.11r at gmail.com>
---
 fuse/main.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fuse/main.c b/fuse/main.c
index 82aca8c..b634782 100644
--- a/fuse/main.c
+++ b/fuse/main.c
@@ -265,8 +265,10 @@ static void erofsfuse_getattr(fuse_req_t req, fuse_ino_t ino,
 	struct erofs_inode vi = { .sbi = &g_sbi, .nid = erofsfuse_to_nid(ino) };
 
 	ret = erofs_read_inode_from_disk(&vi);
-	if (ret < 0)
+	if (ret < 0) {
 		fuse_reply_err(req, -ret);
+		return;
+	}
 
 	erofsfuse_fill_stat(&vi, &stbuf);
 	stbuf.st_ino = ino;
-- 
2.51.0.windows.1