From ca794c8e9583eb660f535af32c8c8281a284f270 Mon Sep 17 00:00:00 2001

From: Daniel Mack <daniel@zonque.org>

Date: Tue, 7 Oct 2014 11:32:07 +0200

Subject: [PATCH] sd-bus: fix use-after-free in close_kdbus_msg()

Walk the items first, then free the memory of the message.

Also, while at it, make coverity happy with an explicit (void) prefix.

We intentionally ignore the return value here.

---

 src/libsystemd/sd-bus/bus-kernel.c | 4 ++--

 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/libsystemd/sd-bus/bus-kernel.c b/src/libsystemd/sd-bus/bus-kernel.c

index 92407133be..b431d78139 100644

--- a/src/libsystemd/sd-bus/bus-kernel.c

+++ b/src/libsystemd/sd-bus/bus-kernel.c

@@ -808,8 +808,6 @@ static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) {

         cmd.flags = 0;

         cmd.offset = (uint8_t *)k - (uint8_t *)bus->kdbus_buffer;

-        ioctl(bus->input_fd, KDBUS_CMD_FREE, &cmd);

-

         KDBUS_ITEM_FOREACH(d, k, items) {

                 if (d->type == KDBUS_ITEM_FDS)

@@ -817,6 +815,8 @@ static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) {

                 else if (d->type == KDBUS_ITEM_PAYLOAD_MEMFD)

                         safe_close(d->memfd.fd);

         }

+

+        (void) ioctl(bus->input_fd, KDBUS_CMD_FREE, &cmd);

 }

 int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m, bool hint_sync_call) {