Merge tag 'io_uring-6.8-2024-01-26' of git://git.kernel.dk/linux

Pull io_uring fix from Jens Axboe:
 "Just a single tweak to the newly added IORING_OP_FIXED_FD_INSTALL from
  Paul, ensuring it goes via the audit path and playing it safe by
  excluding it from using registered creds"

* tag 'io_uring-6.8-2024-01-26' of git://git.kernel.dk/linux:
  io_uring: enable audit and restrict cred override for IORING_OP_FIXED_FD_INSTALL

Author: torvalds

io_uring/opdef.c

@@ -471,7 +471,6 @@ const struct io_issue_def io_issue_defs[] = {
 	},
 	[IORING_OP_FIXED_FD_INSTALL] = {
 		.needs_file		= 1,
-		.audit_skip		= 1,
 		.prep			= io_install_fixed_fd_prep,
 		.issue			= io_install_fixed_fd,
 	},

io_uring/openclose.c

@@ -277,6 +277,10 @@ int io_install_fixed_fd_prep(struct io_kiocb *req, const struct io_uring_sqe *sq
 	if (flags & ~IORING_FIXED_FD_NO_CLOEXEC)
 		return -EINVAL;
 
+	/* ensure the task's creds are used when installing/receiving fds */
+	if (req->flags & REQ_F_CREDS)
+		return -EPERM;
+
 	/* default to O_CLOEXEC, disable if IORING_FIXED_FD_NO_CLOEXEC is set */
 	ifi = io_kiocb_to_cmd(req, struct io_fixed_install);
 	ifi->o_flags = O_CLOEXEC;