If IORING_FILE_INDEX_ALLOC is set asking for an allocated slot, the
helper doesn't check if we actually have a file table or not. The non
alloc path does do that correctly, and returns -ENXIO if we haven't set
one up.
Do the same for the allocated path, avoiding a NULL pointer dereference
when trying to find a free bit.
Fixes: a7c41b4687f5 ("io_uring: let IORING_OP_FILES_UPDATE support choosing fixed file slots")
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
fs/io_uring.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index cddc0e8490af..a01ea49f3017 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7973,6 +7973,9 @@ static int io_files_update_with_index_alloc(struct io_kiocb *req,
struct file *file;
int ret, fd;
+ if (!req->ctx->file_data)
+ return -ENXIO;
+
for (done = 0; done < req->rsrc_update.nr_args; done++) {
if (copy_from_user(&fd, &fds[done], sizeof(fd))) {
ret = -EFAULT;
--
2.35.1
--
Jens Axboe
