From 55d42a0c3f9ccd07c199e0ddbe1ba87572d30074 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 5 Nov 2024 17:52:35 -0800 Subject: [PATCH] selftests: net: add a test for closing a netlink socket ith dump in progress Close a socket with dump in progress. We need a dump which generates enough info not to fit into a single skb. Policy dump fits the bill. Use the trick discovered by syzbot for keeping a ref on the socket longer than just close, with mqueue. TAP version 13 1..3 # Starting 3 tests from 1 test cases. # RUN global.test_sanity ... # OK global.test_sanity ok 1 global.test_sanity # RUN global.close_in_progress ... # OK global.close_in_progress ok 2 global.close_in_progress # RUN global.close_with_ref ... # OK global.close_with_ref ok 3 global.close_with_ref # PASSED: 3 / 3 tests passed. # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0 Note that this test is not expected to fail but rather crash the kernel if we get the cleanup wrong. Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20241106015235.2458807-2-kuba@kernel.org Signed-off-by: Jakub Kicinski --- tools/testing/selftests/net/Makefile | 1 + tools/testing/selftests/net/netlink-dumps.c | 110 ++++++++++++++++++++ 2 files changed, 111 insertions(+) create mode 100644 tools/testing/selftests/net/netlink-dumps.c diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index 649f1fe0dc46..5e86f7a51b43 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -78,6 +78,7 @@ TEST_PROGS += test_vxlan_vnifiltering.sh TEST_GEN_FILES += io_uring_zerocopy_tx TEST_PROGS += io_uring_zerocopy_tx.sh TEST_GEN_FILES += bind_bhash +TEST_GEN_PROGS += netlink-dumps TEST_GEN_PROGS += sk_bind_sendto_listen TEST_GEN_PROGS += sk_connect_zero_addr TEST_GEN_PROGS += sk_so_peek_off diff --git a/tools/testing/selftests/net/netlink-dumps.c b/tools/testing/selftests/net/netlink-dumps.c new file mode 100644 index 000000000000..7ee6dcd334df --- /dev/null +++ b/tools/testing/selftests/net/netlink-dumps.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include "../kselftest_harness.h" + +static const struct { + struct nlmsghdr nlhdr; + struct genlmsghdr genlhdr; + struct nlattr ahdr; + __u16 val; + __u16 pad; +} dump_policies = { + .nlhdr = { + .nlmsg_len = sizeof(dump_policies), + .nlmsg_type = GENL_ID_CTRL, + .nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP, + .nlmsg_seq = 1, + }, + .genlhdr = { + .cmd = CTRL_CMD_GETPOLICY, + .version = 2, + }, + .ahdr = { + .nla_len = 6, + .nla_type = CTRL_ATTR_FAMILY_ID, + }, + .val = GENL_ID_CTRL, + .pad = 0, +}; + +// Sanity check for the test itself, make sure the dump doesn't fit in one msg +TEST(test_sanity) +{ + int netlink_sock; + char buf[8192]; + ssize_t n; + + netlink_sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC); + ASSERT_GE(netlink_sock, 0); + + n = send(netlink_sock, &dump_policies, sizeof(dump_policies), 0); + ASSERT_EQ(n, sizeof(dump_policies)); + + n = recv(netlink_sock, buf, sizeof(buf), MSG_DONTWAIT); + ASSERT_GE(n, sizeof(struct nlmsghdr)); + + n = recv(netlink_sock, buf, sizeof(buf), MSG_DONTWAIT); + ASSERT_GE(n, sizeof(struct nlmsghdr)); + + close(netlink_sock); +} + +TEST(close_in_progress) +{ + int netlink_sock; + ssize_t n; + + netlink_sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC); + ASSERT_GE(netlink_sock, 0); + + n = send(netlink_sock, &dump_policies, sizeof(dump_policies), 0); + ASSERT_EQ(n, sizeof(dump_policies)); + + close(netlink_sock); +} + +TEST(close_with_ref) +{ + char cookie[NOTIFY_COOKIE_LEN] = {}; + int netlink_sock, mq_fd; + struct sigevent sigev; + ssize_t n; + + netlink_sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC); + ASSERT_GE(netlink_sock, 0); + + n = send(netlink_sock, &dump_policies, sizeof(dump_policies), 0); + ASSERT_EQ(n, sizeof(dump_policies)); + + mq_fd = syscall(__NR_mq_open, "sed", O_CREAT | O_WRONLY, 0600, 0); + ASSERT_GE(mq_fd, 0); + + memset(&sigev, 0, sizeof(sigev)); + sigev.sigev_notify = SIGEV_THREAD; + sigev.sigev_value.sival_ptr = cookie; + sigev.sigev_signo = netlink_sock; + + syscall(__NR_mq_notify, mq_fd, &sigev); + + close(netlink_sock); + + // give mqueue time to fire + usleep(100 * 1000); +} + +TEST_HARNESS_MAIN