From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 393EF25A2BA; Mon, 12 May 2025 08:56:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747040189; cv=none; b=XMcFrFElDhvTFscUKj0HojrAS/m3YdY1NQDaRSScP88fkjIEqnibaVLxIVUM3RMY8co5bhfP418bc3CjhEzuFLqpfbOlXqUHDMe0bh6hN0JE3dIrE2pBxvtb6sZ8wbmODNh4Bn55XExe5kO9k5fVgYvlJHu2dE/U49PBUgdTubg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747040189; c=relaxed/simple; bh=q/v2mAlkLcg0KsGCqgczqMc5SELp2xv2/mYAT5TDFss=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=dhJ9QQmb1cTwP8upfuCWktQwcSityjbxqLOPfMCsdP1mJzTC/1tGeYhUf5bHqYU/7Y/IcjPYaBT1EhC1b2b36WZK2BpIxd1cdwFFsTDOMb3XJ1zBjJMwZ5Xe2TTyXTDVVN2keVk7jUeqsi8TgwJEDYWS+MLq4gUk/PkrAGI3K4E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NodzJqK7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NodzJqK7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 37483C4CEE9; Mon, 12 May 2025 08:56:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747040189; bh=q/v2mAlkLcg0KsGCqgczqMc5SELp2xv2/mYAT5TDFss=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=NodzJqK7fyaSDTRsaymrYOX+v1fpWq22DMFIVaIstRiYXJXa21WlyVtvLsI/3En4p oHnRw5Vm+NRL/9VmgCSW/cbzuRIgPGoh1uY5ox/n8oWe3c2KRf2dv5BIkG7R4AHxw+ YUu+IH9BOtW3STnAMJTvy/j4oy6OwAKjg7cprzzKAJZ+ZEJAsw+EUZU2rG/hI/vSk6 hlOrtsLzJvEDwxbaXU6+CHnD3SLAJMw+FwMQ9aq41Gbe82zHsywkSxklDSuEloxWJx eOfmizMhfvzupVJUyB0S2TgWhvAwKPFVp9tt9Kd1KKz/BiOwF5061gDAHuV7/QNkii /QHW1Gt9ystmw== From: Christian Brauner Date: Mon, 12 May 2025 10:55:28 +0200 Subject: [PATCH v6 9/9] selftests/coredump: add tests for AF_UNIX coredumps Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20250512-work-coredump-socket-v6-9-c51bc3450727@kernel.org> References: <20250512-work-coredump-socket-v6-0-c51bc3450727@kernel.org> In-Reply-To: <20250512-work-coredump-socket-v6-0-c51bc3450727@kernel.org> To: linux-fsdevel@vger.kernel.org, Jann Horn , Daniel Borkmann , Kuniyuki Iwashima Cc: Eric Dumazet , Oleg Nesterov , "David S. Miller" , Alexander Viro , Daan De Meyer , David Rheinsberg , Jakub Kicinski , Jan Kara , Lennart Poettering , Luca Boccassi , Mike Yuan , Paolo Abeni , Simon Horman , =?utf-8?q?Zbigniew_J=C4=99drzejewski-Szmek?= , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-security-module@vger.kernel.org, Christian Brauner , Alexander Mikhalitsyn X-Mailer: b4 0.15-dev-c25d1 X-Developer-Signature: v=1; a=openpgp-sha256; l=29673; i=brauner@kernel.org; h=from:subject:message-id; bh=q/v2mAlkLcg0KsGCqgczqMc5SELp2xv2/mYAT5TDFss=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWQobm8//rnNuGX/V9dJmRcNHjRFaHSnNVn3qW19cG3Wf c8yD69THaUsDGJcDLJiiiwO7Sbhcst5KjYbZWrAzGFlAhnCwMUpABPRvcDI0GJwunp2jei5i9zr fRqCHoc8Orr+lPBM7/d7r1+NdZTqqGH4H67VE/2ajSFAy1XKdbvcJku/txE/LgY+07jEG+Q1beF FHgA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Add a simple test for generating coredumps via AF_UNIX sockets. Signed-off-by: Christian Brauner --- tools/testing/selftests/coredump/stackdump_test.c | 956 +++++++++++++++++++++- 1 file changed, 955 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/coredump/stackdump_test.c b/tools/testing/selftests/coredump/stackdump_test.c index fe3c728cd6be..5a74612ae42e 100644 --- a/tools/testing/selftests/coredump/stackdump_test.c +++ b/tools/testing/selftests/coredump/stackdump_test.c @@ -1,14 +1,20 @@ // SPDX-License-Identifier: GPL-2.0 #include +#include #include #include #include #include +#include #include +#include +#include +#include #include #include "../kselftest_harness.h" +#include "../pidfd/pidfd.h" #define STACKDUMP_FILE "stack_values" #define STACKDUMP_SCRIPT "stackdump" @@ -35,6 +41,7 @@ static void crashing_child(void) FIXTURE(coredump) { char original_core_pattern[256]; + pid_t pid_coredump_server; }; FIXTURE_SETUP(coredump) @@ -44,6 +51,7 @@ FIXTURE_SETUP(coredump) char *dir; int ret; + self->pid_coredump_server = -ESRCH; file = fopen("/proc/sys/kernel/core_pattern", "r"); ASSERT_NE(NULL, file); @@ -61,10 +69,15 @@ FIXTURE_TEARDOWN(coredump) { const char *reason; FILE *file; - int ret; + int ret, status; unlink(STACKDUMP_FILE); + if (self->pid_coredump_server > 0) { + kill(self->pid_coredump_server, SIGTERM); + waitpid(self->pid_coredump_server, &status, 0); + } + file = fopen("/proc/sys/kernel/core_pattern", "w"); if (!file) { reason = "Unable to open core_pattern"; @@ -154,4 +167,945 @@ TEST_F_TIMEOUT(coredump, stackdump, 120) fclose(file); } +TEST_F(coredump, socket) +{ + int fd, pidfd, ret, status; + FILE *file; + pid_t pid, pid_coredump_server; + struct stat st; + char core_file[PATH_MAX]; + struct pidfd_info info = {}; + int ipc_sockets[2]; + char c; + + ASSERT_EQ(unshare(CLONE_NEWNS), 0); + ASSERT_EQ(mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL), 0); + ASSERT_EQ(mount(NULL, "/tmp", "tmpfs", 0, NULL), 0); + + ret = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets); + ASSERT_EQ(ret, 0); + + pid_coredump_server = fork(); + ASSERT_GE(pid_coredump_server, 0); + if (pid_coredump_server == 0) { + int fd_server, fd_coredump, fd_peer_pidfd, fd_core_file; + __u64 peer_cookie, server_cookie; + socklen_t fd_peer_pidfd_len, peer_cookie_len, server_cookie_len; + struct sockaddr_un coredump_sk = { + .sun_family = AF_UNIX, + }; + size_t coredump_sk_len; + + close(ipc_sockets[0]); + + fd_server = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0); + if (fd_server < 0) + _exit(EXIT_FAILURE); + + server_cookie_len = sizeof(server_cookie); + ret = getsockopt(fd_server, SOL_SOCKET, SO_COOKIE, + &server_cookie, &server_cookie_len); + if (ret < 0) { + fprintf(stderr, "%m - Failed to retrieve cookie for coredump socket server\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + coredump_sk_len = snprintf(coredump_sk.sun_path, + sizeof(coredump_sk.sun_path), + "@coredump.socket %" PRIu64, server_cookie); + if (coredump_sk_len < 0 || coredump_sk_len >= sizeof(coredump_sk.sun_path)) { + fprintf(stderr, "Unable to create coredump socket path\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + file = fopen("/proc/sys/kernel/core_pattern", "w"); + if (!file) { + fprintf(stderr, "Unable to open core_pattern\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + ret = fprintf(file, "%s", coredump_sk.sun_path); + fclose(file); + if (ret < 0) { + fprintf(stderr, "Unable to write to core_pattern\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + coredump_sk.sun_path[0] = '\0'; + memcpy(coredump_sk.sun_path, "\0coredump.socket", sizeof("coredump.socket")); + coredump_sk_len = offsetof(struct sockaddr_un, sun_path) + sizeof("coredump.socket"); + ret = bind(fd_server, (const struct sockaddr *)&coredump_sk, coredump_sk_len); + if (ret < 0) { + fprintf(stderr, "Failed to bind coredump socket\n"); + close(fd_server); + close(ipc_sockets[1]); + _exit(EXIT_FAILURE); + } + + ret = listen(fd_server, 1); + if (ret < 0) { + fprintf(stderr, "Failed to listen on coredump socket\n"); + close(fd_server); + close(ipc_sockets[1]); + _exit(EXIT_FAILURE); + } + + if (write_nointr(ipc_sockets[1], "1", 1) < 0) { + close(fd_server); + close(ipc_sockets[1]); + _exit(EXIT_FAILURE); + } + + close(ipc_sockets[1]); + + fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC); + if (fd_coredump < 0) { + fprintf(stderr, "Failed to accept coredump socket connection\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + peer_cookie_len = sizeof(peer_cookie); + ret = getsockopt(fd_coredump, SOL_SOCKET, SO_COOKIE, + &peer_cookie, &peer_cookie_len); + if (ret < 0) { + fprintf(stderr, "%m - Failed to retrieve cookie for coredump socket connection\n"); + close(fd_coredump); + close(fd_server); + _exit(EXIT_FAILURE); + } + + fd_peer_pidfd_len = sizeof(fd_peer_pidfd); + ret = getsockopt(fd_coredump, SOL_SOCKET, SO_PEERPIDFD, + &fd_peer_pidfd, &fd_peer_pidfd_len); + if (ret < 0) { + fprintf(stderr, "%m - Failed to retrieve peer pidfd for coredump socket connection\n"); + close(fd_coredump); + close(fd_server); + _exit(EXIT_FAILURE); + } + + memset(&info, 0, sizeof(info)); + info.mask = PIDFD_INFO_EXIT | PIDFD_INFO_COREDUMP; + ret = ioctl(fd_peer_pidfd, PIDFD_GET_INFO, &info); + if (ret < 0) { + fprintf(stderr, "Failed to retrieve pidfd info from peer pidfd for coredump socket connection\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (!(info.mask & PIDFD_INFO_COREDUMP)) { + fprintf(stderr, "Missing coredump information from coredumping task\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (!(info.coredump_mask & PIDFD_COREDUMPED)) { + fprintf(stderr, "Received connection from non-coredumping task\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (!info.coredump_cookie) { + fprintf(stderr, "Missing coredump cookie\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (info.coredump_cookie != peer_cookie) { + fprintf(stderr, "Mismatching coredump cookies\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + fd_core_file = creat("/tmp/coredump.file", 0644); + if (fd_core_file < 0) { + fprintf(stderr, "Failed to create coredump file\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + for (;;) { + char buffer[4096]; + ssize_t bytes_read, bytes_write; + + bytes_read = read(fd_coredump, buffer, sizeof(buffer)); + if (bytes_read < 0) { + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + close(fd_core_file); + _exit(EXIT_FAILURE); + } + + if (bytes_read == 0) + break; + + bytes_write = write(fd_core_file, buffer, bytes_read); + if (bytes_read != bytes_write) { + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + close(fd_core_file); + _exit(EXIT_FAILURE); + } + } + + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + close(fd_core_file); + _exit(EXIT_SUCCESS); + } + self->pid_coredump_server = pid_coredump_server; + + EXPECT_EQ(close(ipc_sockets[1]), 0); + ASSERT_EQ(read_nointr(ipc_sockets[0], &c, 1), 1); + EXPECT_EQ(close(ipc_sockets[0]), 0); + + pid = fork(); + ASSERT_GE(pid, 0); + if (pid == 0) + crashing_child(); + + pidfd = sys_pidfd_open(pid, 0); + ASSERT_GE(pidfd, 0); + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFSIGNALED(status)); + ASSERT_TRUE(WCOREDUMP(status)); + + info.mask = PIDFD_INFO_EXIT | PIDFD_INFO_COREDUMP; + ASSERT_EQ(ioctl(pidfd, PIDFD_GET_INFO, &info), 0); + ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0); + ASSERT_GT((info.coredump_mask & PIDFD_COREDUMPED), 0); + + waitpid(pid_coredump_server, &status, 0); + self->pid_coredump_server = -ESRCH; + ASSERT_TRUE(WIFEXITED(status)); + ASSERT_EQ(WEXITSTATUS(status), 0); + + ASSERT_EQ(stat("/tmp/coredump.file", &st), 0); + ASSERT_GT(st.st_size, 0); + /* + * We should somehow validate the produced core file. + * For now just allow for visual inspection + */ + system("file /tmp/coredump.file"); +} + +TEST_F(coredump, socket_recycled_cookie) +{ + int fd, pidfd, ret, status; + FILE *file; + pid_t pid, pid_coredump_server; + struct stat st; + char core_file[PATH_MAX]; + struct pidfd_info info = {}; + int ipc_sockets[2]; + char c; + + ASSERT_EQ(unshare(CLONE_NEWNS), 0); + ASSERT_EQ(mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL), 0); + ASSERT_EQ(mount(NULL, "/tmp", "tmpfs", 0, NULL), 0); + + ret = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets); + ASSERT_EQ(ret, 0); + + pid_coredump_server = fork(); + ASSERT_GE(pid_coredump_server, 0); + if (pid_coredump_server == 0) { + int fd_server, fd_coredump, fd_peer_pidfd, fd_core_file; + __u64 peer_cookie, server_cookie; + socklen_t fd_peer_pidfd_len, peer_cookie_len, server_cookie_len; + struct sockaddr_un coredump_sk = { + .sun_family = AF_UNIX, + }; + size_t coredump_sk_len; + + close(ipc_sockets[0]); + + fd_server = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0); + if (fd_server < 0) + _exit(EXIT_FAILURE); + + server_cookie_len = sizeof(server_cookie); + ret = getsockopt(fd_server, SOL_SOCKET, SO_COOKIE, + &server_cookie, &server_cookie_len); + if (ret < 0) { + fprintf(stderr, "%m - Failed to retrieve cookie for coredump socket server\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + /* Write invalid socket cookie to core_pattern. */ + coredump_sk_len = snprintf(coredump_sk.sun_path, + sizeof(coredump_sk.sun_path), + "@coredump.socket %" PRIu64, 0); + if (coredump_sk_len < 0 || coredump_sk_len >= sizeof(coredump_sk.sun_path)) { + fprintf(stderr, "Unable to create coredump socket path\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + file = fopen("/proc/sys/kernel/core_pattern", "w"); + if (!file) { + fprintf(stderr, "Unable to open core_pattern\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + ret = fprintf(file, "%s", coredump_sk.sun_path); + fclose(file); + if (ret < 0) { + fprintf(stderr, "Unable to write to core_pattern\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + coredump_sk.sun_path[0] = '\0'; + memcpy(coredump_sk.sun_path, "\0coredump.socket", sizeof("coredump.socket")); + coredump_sk_len = offsetof(struct sockaddr_un, sun_path) + sizeof("coredump.socket"); + ret = bind(fd_server, (const struct sockaddr *)&coredump_sk, coredump_sk_len); + if (ret < 0) { + fprintf(stderr, "Failed to bind coredump socket\n"); + close(fd_server); + close(ipc_sockets[1]); + _exit(EXIT_FAILURE); + } + + ret = listen(fd_server, 1); + if (ret < 0) { + fprintf(stderr, "Failed to listen on coredump socket\n"); + close(fd_server); + close(ipc_sockets[1]); + _exit(EXIT_FAILURE); + } + + if (write_nointr(ipc_sockets[1], "1", 1) < 0) { + close(fd_server); + close(ipc_sockets[1]); + _exit(EXIT_FAILURE); + } + + close(ipc_sockets[1]); + + fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC); + if (fd_coredump < 0) { + fprintf(stderr, "Failed to accept coredump socket connection\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + peer_cookie_len = sizeof(peer_cookie); + ret = getsockopt(fd_coredump, SOL_SOCKET, SO_COOKIE, + &peer_cookie, &peer_cookie_len); + if (ret < 0) { + fprintf(stderr, "%m - Failed to retrieve cookie for coredump socket connection\n"); + close(fd_coredump); + close(fd_server); + _exit(EXIT_FAILURE); + } + + fd_peer_pidfd_len = sizeof(fd_peer_pidfd); + ret = getsockopt(fd_coredump, SOL_SOCKET, SO_PEERPIDFD, + &fd_peer_pidfd, &fd_peer_pidfd_len); + if (ret < 0) { + fprintf(stderr, "%m - Failed to retrieve peer pidfd for coredump socket connection\n"); + close(fd_coredump); + close(fd_server); + _exit(EXIT_FAILURE); + } + + memset(&info, 0, sizeof(info)); + info.mask = PIDFD_INFO_EXIT | PIDFD_INFO_COREDUMP; + ret = ioctl(fd_peer_pidfd, PIDFD_GET_INFO, &info); + if (ret < 0) { + fprintf(stderr, "Failed to retrieve pidfd info from peer pidfd for coredump socket connection\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (!(info.mask & PIDFD_INFO_COREDUMP)) { + fprintf(stderr, "Missing coredump information from coredumping task\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (!(info.coredump_mask & PIDFD_COREDUMPED)) { + fprintf(stderr, "Received connection from non-coredumping task\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (!info.coredump_cookie) { + fprintf(stderr, "Missing coredump cookie\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (info.coredump_cookie != peer_cookie) { + fprintf(stderr, "Mismatching coredump cookies\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + fd_core_file = creat("/tmp/coredump.file", 0644); + if (fd_core_file < 0) { + fprintf(stderr, "Failed to create coredump file\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + for (;;) { + char buffer[4096]; + ssize_t bytes_read, bytes_write; + + bytes_read = read(fd_coredump, buffer, sizeof(buffer)); + if (bytes_read < 0) { + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + close(fd_core_file); + _exit(EXIT_FAILURE); + } + + if (bytes_read == 0) + break; + + bytes_write = write(fd_core_file, buffer, bytes_read); + if (bytes_read != bytes_write) { + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + close(fd_core_file); + _exit(EXIT_FAILURE); + } + } + + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + close(fd_core_file); + _exit(EXIT_SUCCESS); + } + self->pid_coredump_server = pid_coredump_server; + + EXPECT_EQ(close(ipc_sockets[1]), 0); + ASSERT_EQ(read_nointr(ipc_sockets[0], &c, 1), 1); + EXPECT_EQ(close(ipc_sockets[0]), 0); + + pid = fork(); + ASSERT_GE(pid, 0); + if (pid == 0) + crashing_child(); + + pidfd = sys_pidfd_open(pid, 0); + ASSERT_GE(pidfd, 0); + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFSIGNALED(status)); + ASSERT_FALSE(WCOREDUMP(status)); + + info.mask = PIDFD_INFO_EXIT | PIDFD_INFO_COREDUMP; + ASSERT_EQ(ioctl(pidfd, PIDFD_GET_INFO, &info), 0); + ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0); + ASSERT_EQ((info.coredump_mask & PIDFD_COREDUMPED), 0); + + ASSERT_EQ(kill(pid_coredump_server, SIGKILL), 0); + waitpid(pid_coredump_server, &status, 0); + self->pid_coredump_server = -ESRCH; + ASSERT_TRUE(WIFSIGNALED(status)); + ASSERT_EQ(WTERMSIG(status), SIGKILL); + + ASSERT_NE(stat("/tmp/coredump.file", &st), 0); + ASSERT_EQ(errno, ENOENT); +} + +TEST_F(coredump, socket_missing_cookie) +{ + int fd, pidfd, ret, status; + FILE *file; + pid_t pid, pid_coredump_server; + struct stat st; + char core_file[PATH_MAX]; + struct pidfd_info info = {}; + int ipc_sockets[2]; + char c; + + ASSERT_EQ(unshare(CLONE_NEWNS), 0); + ASSERT_EQ(mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL), 0); + ASSERT_EQ(mount(NULL, "/tmp", "tmpfs", 0, NULL), 0); + + ret = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets); + ASSERT_EQ(ret, 0); + + pid_coredump_server = fork(); + ASSERT_GE(pid_coredump_server, 0); + if (pid_coredump_server == 0) { + int fd_server, fd_coredump, fd_peer_pidfd, fd_core_file; + __u64 peer_cookie, server_cookie; + socklen_t fd_peer_pidfd_len, peer_cookie_len, server_cookie_len; + struct sockaddr_un coredump_sk = { + .sun_family = AF_UNIX, + }; + size_t coredump_sk_len; + + close(ipc_sockets[0]); + + fd_server = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0); + if (fd_server < 0) + _exit(EXIT_FAILURE); + + server_cookie_len = sizeof(server_cookie); + ret = getsockopt(fd_server, SOL_SOCKET, SO_COOKIE, + &server_cookie, &server_cookie_len); + if (ret < 0) { + fprintf(stderr, "%m - Failed to retrieve cookie for coredump socket server\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + /* Don't write socket cookie to core_pattern. */ + coredump_sk_len = snprintf(coredump_sk.sun_path, + sizeof(coredump_sk.sun_path), + "@coredump.socket"); + if (coredump_sk_len < 0 || coredump_sk_len >= sizeof(coredump_sk.sun_path)) { + fprintf(stderr, "Unable to create coredump socket path\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + file = fopen("/proc/sys/kernel/core_pattern", "w"); + if (!file) { + fprintf(stderr, "Unable to open core_pattern\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + ret = fprintf(file, "%s", coredump_sk.sun_path); + fclose(file); + if (ret < 0) { + fprintf(stderr, "Unable to write to core_pattern\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + coredump_sk.sun_path[0] = '\0'; + memcpy(coredump_sk.sun_path, "\0coredump.socket", sizeof("coredump.socket")); + coredump_sk_len = offsetof(struct sockaddr_un, sun_path) + sizeof("coredump.socket"); + ret = bind(fd_server, (const struct sockaddr *)&coredump_sk, coredump_sk_len); + if (ret < 0) { + fprintf(stderr, "Failed to bind coredump socket\n"); + close(fd_server); + close(ipc_sockets[1]); + _exit(EXIT_FAILURE); + } + + ret = listen(fd_server, 1); + if (ret < 0) { + fprintf(stderr, "Failed to listen on coredump socket\n"); + close(fd_server); + close(ipc_sockets[1]); + _exit(EXIT_FAILURE); + } + + if (write_nointr(ipc_sockets[1], "1", 1) < 0) { + close(fd_server); + close(ipc_sockets[1]); + _exit(EXIT_FAILURE); + } + + close(ipc_sockets[1]); + + fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC); + if (fd_coredump < 0) { + fprintf(stderr, "Failed to accept coredump socket connection\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + peer_cookie_len = sizeof(peer_cookie); + ret = getsockopt(fd_coredump, SOL_SOCKET, SO_COOKIE, + &peer_cookie, &peer_cookie_len); + if (ret < 0) { + fprintf(stderr, "%m - Failed to retrieve cookie for coredump socket connection\n"); + close(fd_coredump); + close(fd_server); + _exit(EXIT_FAILURE); + } + + fd_peer_pidfd_len = sizeof(fd_peer_pidfd); + ret = getsockopt(fd_coredump, SOL_SOCKET, SO_PEERPIDFD, + &fd_peer_pidfd, &fd_peer_pidfd_len); + if (ret < 0) { + fprintf(stderr, "%m - Failed to retrieve peer pidfd for coredump socket connection\n"); + close(fd_coredump); + close(fd_server); + _exit(EXIT_FAILURE); + } + + memset(&info, 0, sizeof(info)); + info.mask = PIDFD_INFO_EXIT | PIDFD_INFO_COREDUMP; + ret = ioctl(fd_peer_pidfd, PIDFD_GET_INFO, &info); + if (ret < 0) { + fprintf(stderr, "Failed to retrieve pidfd info from peer pidfd for coredump socket connection\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (!(info.mask & PIDFD_INFO_COREDUMP)) { + fprintf(stderr, "Missing coredump information from coredumping task\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (!(info.coredump_mask & PIDFD_COREDUMPED)) { + fprintf(stderr, "Received connection from non-coredumping task\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (!info.coredump_cookie) { + fprintf(stderr, "Missing coredump cookie\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (info.coredump_cookie != peer_cookie) { + fprintf(stderr, "Mismatching coredump cookies\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + fd_core_file = creat("/tmp/coredump.file", 0644); + if (fd_core_file < 0) { + fprintf(stderr, "Failed to create coredump file\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + for (;;) { + char buffer[4096]; + ssize_t bytes_read, bytes_write; + + bytes_read = read(fd_coredump, buffer, sizeof(buffer)); + if (bytes_read < 0) { + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + close(fd_core_file); + _exit(EXIT_FAILURE); + } + + if (bytes_read == 0) + break; + + bytes_write = write(fd_core_file, buffer, bytes_read); + if (bytes_read != bytes_write) { + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + close(fd_core_file); + _exit(EXIT_FAILURE); + } + } + + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + close(fd_core_file); + _exit(EXIT_SUCCESS); + } + self->pid_coredump_server = pid_coredump_server; + + EXPECT_EQ(close(ipc_sockets[1]), 0); + ASSERT_EQ(read_nointr(ipc_sockets[0], &c, 1), 1); + EXPECT_EQ(close(ipc_sockets[0]), 0); + + pid = fork(); + ASSERT_GE(pid, 0); + if (pid == 0) + crashing_child(); + + pidfd = sys_pidfd_open(pid, 0); + ASSERT_GE(pidfd, 0); + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFSIGNALED(status)); + ASSERT_FALSE(WCOREDUMP(status)); + + info.mask = PIDFD_INFO_EXIT | PIDFD_INFO_COREDUMP; + ASSERT_EQ(ioctl(pidfd, PIDFD_GET_INFO, &info), 0); + ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0); + ASSERT_EQ((info.coredump_mask & PIDFD_COREDUMPED), 0); + + ASSERT_EQ(kill(pid_coredump_server, SIGKILL), 0); + waitpid(pid_coredump_server, &status, 0); + self->pid_coredump_server = -ESRCH; + ASSERT_TRUE(WIFSIGNALED(status)); + ASSERT_EQ(WTERMSIG(status), SIGKILL); + + ASSERT_NE(stat("/tmp/coredump.file", &st), 0); + ASSERT_EQ(errno, ENOENT); +} + +TEST_F(coredump, socket_detect_userspace_client) +{ + int fd, pidfd, ret, status; + FILE *file; + pid_t pid, pid_coredump_server; + struct stat st; + char core_file[PATH_MAX]; + struct pidfd_info info = {}; + int ipc_sockets[2]; + char c; + + ASSERT_EQ(unshare(CLONE_NEWNS), 0); + ASSERT_EQ(mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL), 0); + ASSERT_EQ(mount(NULL, "/tmp", "tmpfs", 0, NULL), 0); + + ret = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets); + ASSERT_EQ(ret, 0); + + pid_coredump_server = fork(); + ASSERT_GE(pid_coredump_server, 0); + if (pid_coredump_server == 0) { + int fd_server, fd_coredump, fd_peer_pidfd, fd_core_file; + __u64 peer_cookie, server_cookie; + socklen_t fd_peer_pidfd_len, peer_cookie_len, server_cookie_len; + struct sockaddr_un coredump_sk = { + .sun_family = AF_UNIX, + }; + size_t coredump_sk_len; + + close(ipc_sockets[0]); + + fd_server = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0); + if (fd_server < 0) + _exit(EXIT_FAILURE); + + server_cookie_len = sizeof(server_cookie); + ret = getsockopt(fd_server, SOL_SOCKET, SO_COOKIE, + &server_cookie, &server_cookie_len); + if (ret < 0) { + fprintf(stderr, "%m - Failed to retrieve cookie for coredump socket server\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + coredump_sk_len = snprintf(coredump_sk.sun_path, + sizeof(coredump_sk.sun_path), + "@coredump.socket %" PRIu64, server_cookie); + if (coredump_sk_len < 0 || coredump_sk_len >= sizeof(coredump_sk.sun_path)) { + fprintf(stderr, "Unable to create coredump socket path\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + file = fopen("/proc/sys/kernel/core_pattern", "w"); + if (!file) { + fprintf(stderr, "Unable to open core_pattern\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + ret = fprintf(file, "%s", coredump_sk.sun_path); + fclose(file); + if (ret < 0) { + fprintf(stderr, "Unable to write to core_pattern\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + coredump_sk.sun_path[0] = '\0'; + memcpy(coredump_sk.sun_path, "\0coredump.socket", sizeof("coredump.socket")); + coredump_sk_len = offsetof(struct sockaddr_un, sun_path) + sizeof("coredump.socket"); + ret = bind(fd_server, (const struct sockaddr *)&coredump_sk, coredump_sk_len); + if (ret < 0) { + fprintf(stderr, "Failed to bind coredump socket\n"); + close(fd_server); + close(ipc_sockets[1]); + _exit(EXIT_FAILURE); + } + + ret = listen(fd_server, 1); + if (ret < 0) { + fprintf(stderr, "Failed to listen on coredump socket\n"); + close(fd_server); + close(ipc_sockets[1]); + _exit(EXIT_FAILURE); + } + + if (write_nointr(ipc_sockets[1], "1", 1) < 0) { + close(fd_server); + close(ipc_sockets[1]); + _exit(EXIT_FAILURE); + } + + close(ipc_sockets[1]); + + fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC); + if (fd_coredump < 0) { + fprintf(stderr, "Failed to accept coredump socket connection\n"); + close(fd_server); + _exit(EXIT_FAILURE); + } + + peer_cookie_len = sizeof(peer_cookie); + ret = getsockopt(fd_coredump, SOL_SOCKET, SO_COOKIE, + &peer_cookie, &peer_cookie_len); + if (ret < 0) { + fprintf(stderr, "%m - Failed to retrieve cookie for coredump socket connection\n"); + close(fd_coredump); + close(fd_server); + _exit(EXIT_FAILURE); + } + + fd_peer_pidfd_len = sizeof(fd_peer_pidfd); + ret = getsockopt(fd_coredump, SOL_SOCKET, SO_PEERPIDFD, + &fd_peer_pidfd, &fd_peer_pidfd_len); + if (ret < 0) { + fprintf(stderr, "%m - Failed to retrieve peer pidfd for coredump socket connection\n"); + close(fd_coredump); + close(fd_server); + _exit(EXIT_FAILURE); + } + + memset(&info, 0, sizeof(info)); + info.mask = PIDFD_INFO_EXIT | PIDFD_INFO_COREDUMP; + ret = ioctl(fd_peer_pidfd, PIDFD_GET_INFO, &info); + if (ret < 0) { + fprintf(stderr, "Failed to retrieve pidfd info from peer pidfd for coredump socket connection\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (!(info.mask & PIDFD_INFO_COREDUMP)) { + fprintf(stderr, "Missing coredump information from coredumping task\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (info.coredump_mask & PIDFD_COREDUMPED) { + fprintf(stderr, "Received unexpected connection from coredumping task\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + if (info.coredump_cookie) { + fprintf(stderr, "Received unexpected coredump cookie\n"); + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + _exit(EXIT_FAILURE); + } + + close(fd_coredump); + close(fd_server); + close(fd_peer_pidfd); + close(fd_core_file); + _exit(EXIT_SUCCESS); + } + self->pid_coredump_server = pid_coredump_server; + + EXPECT_EQ(close(ipc_sockets[1]), 0); + ASSERT_EQ(read_nointr(ipc_sockets[0], &c, 1), 1); + EXPECT_EQ(close(ipc_sockets[0]), 0); + + pid = fork(); + ASSERT_GE(pid, 0); + if (pid == 0) { + struct sockaddr_un coredump_sk = { + .sun_family = AF_UNIX, + }; + socklen_t coredump_sk_len; + int fd_socket; + ssize_t ret; + + fd_socket = socket(AF_UNIX, SOCK_STREAM, 0); + if (fd_socket < 0) + _exit(EXIT_FAILURE); + + + coredump_sk.sun_path[0] = '\0'; + memcpy(coredump_sk.sun_path, "\0coredump.socket", sizeof("coredump.socket")); + coredump_sk_len = offsetof(struct sockaddr_un, sun_path) + sizeof("coredump.socket"); + + ret = connect(fd_socket, (const struct sockaddr *)&coredump_sk, coredump_sk_len); + if (ret < 0) + _exit(EXIT_FAILURE); + + (void *)write(fd_socket, &(char){ 0 }, 1); + close(fd_socket); + _exit(EXIT_SUCCESS); + } + + pidfd = sys_pidfd_open(pid, 0); + ASSERT_GE(pidfd, 0); + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFEXITED(status)); + ASSERT_EQ(WEXITSTATUS(status), 0); + + info.mask = PIDFD_INFO_EXIT | PIDFD_INFO_COREDUMP; + ASSERT_EQ(ioctl(pidfd, PIDFD_GET_INFO, &info), 0); + ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0); + ASSERT_EQ((info.coredump_mask & PIDFD_COREDUMPED), 0); + + waitpid(pid_coredump_server, &status, 0); + self->pid_coredump_server = -ESRCH; + ASSERT_TRUE(WIFEXITED(status)); + ASSERT_EQ(WEXITSTATUS(status), 0); + + ASSERT_NE(stat("/tmp/coredump.file", &st), 0); + ASSERT_EQ(errno, ENOENT); +} + TEST_HARNESS_MAIN -- 2.47.2