Commit fbf8e721 authored Nov 11, 2014 by Shuah Khan Committed by David S. Miller Nov 11, 2014

selftests/net: psock_fanout seg faults in sock_fanout_read_ring()



The while loop in sock_fanout_read_ring() checks mmap region
bounds after access, causing it to segfault. Fix it to check
count before accessing header->tp_status. This problem can be
reproduced consistently when the test in run as follows:

    make -C tools/testing/selftests TARGETS=net run_tests
    or
    make run_tests from tools/testing/selftests
    or
    make run_test from tools/testing/selftests/net

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent caa13a9f

tools/testing/selftests/net/psock_fanout.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -128,7 +128,7 @@ static int sock_fanout_read_ring(int fd, void *ring)
		struct tpacket2_hdr *header = ring;
		int count = 0;

		while (header->tp_status & TP_STATUS_USER && count < RING_NUM_FRAMES) {
		while (count < RING_NUM_FRAMES && header->tp_status & TP_STATUS_USER) {
		count++;
		header = ring + (count * getpagesize());
		}