selftests: net: fix "buffer overflow detected" for tap.c

2026-01-11T14:22:06+00:00

[ Upstream commit 472c5dd6b95c02b3e5d7395acf542150e91165e7 ] When the selftest 'tap.c' is compiled with '-D_FORTIFY_SOURCE=3', the strcpy() in rtattr_add_strsz() is replaced with a checked version which causes the test to consistently fail when compiled with toolchains for which this option is enabled by default. TAP version 13 1..3 # Starting 3 tests from 1 test cases. # RUN tap.test_packet_valid_udp_gso ... *** buffer overflow detected ***: terminated # test_packet_valid_udp_gso: Test terminated by assertion # FAIL tap.test_packet_valid_udp_gso not ok 1 tap.test_packet_valid_udp_gso # RUN tap.test_packet_valid_udp_csum ... *** buffer overflow detected ***: terminated # test_packet_valid_udp_csum: Test terminated by assertion # FAIL tap.test_packet_valid_udp_csum not ok 2 tap.test_packet_valid_udp_csum # RUN tap.test_packet_crash_tap_invalid_eth_proto ... *** buffer overflow detected ***: terminated # test_packet_crash_tap_invalid_eth_proto: Test terminated by assertion # FAIL tap.test_packet_crash_tap_invalid_eth_proto not ok 3 tap.test_packet_crash_tap_invalid_eth_proto # FAILED: 0 / 3 tests passed. # Totals: pass:0 fail:3 xfail:0 xpass:0 skip:0 error:0 A buffer overflow is detected by the fortified glibc __strcpy_chk() since the __builtin_object_size() of `RTA_DATA(rta)` is incorrectly reported as 1, even though there is ample space in its bounding buffer `req`. Additionally, given that IFLA_IFNAME also expects a null-terminated string, callers of rtaddr_add_str{,sz}() could simply use the rtaddr_add_strsz() variant. (which has been renamed to remove the trailing `sz`) memset() has been used for this function since it is unchecked and thus circumvents the issue discussed in the previous paragraph. Fixes: 2e64fe4624d1 ("selftests: add few test cases for tap driver") Signed-off-by: Alice C. Munduruca Reviewed-by: Cengiz Can Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20251216170641.250494-1-alice.munduruca@canonical.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

selftests: add few test cases for tap driver

2022-08-05T07:59:15+00:00

Few test cases related to the fix for 924a9bc362a5: "net: check if protocol extracted by virtio_net_hdr_set_proto is correct" Need test for the case when a non-standard packet (GSO without NEEDS_CSUM) sent to the tap device causes a BUG check in the tap driver. Signed-off-by: Cezar Bulinaru Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller

kernel/linux.git/tools/testing/selftests/net/tap.c, branch v6.6.131

selftests: net: fix "buffer overflow detected" for tap.c

selftests: add few test cases for tap driver