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>
diff --git a/tools/testing/selftests/net/psock_fanout.c b/tools/testing/selftests/net/psock_fanout.c
index 57b9c2b..6f67333 100644
--- a/tools/testing/selftests/net/psock_fanout.c
+++ b/tools/testing/selftests/net/psock_fanout.c
@@ -128,7 +128,7 @@
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());
}