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 51C68426D11; Wed, 29 Apr 2026 22:30:08 +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=1777501808; cv=none; b=lFkT8GGfZzTDHpmO8tS6yA1WQh2m1HBMv5ZYLrbxV9XCAC+H1TxBJSMMo/yR5OnvdQyZSdSgtc6ue5KzEF+QZfAeslEeYPsT0xlsZyvYqnRDEcpFEJzYjclyI+Fruxlw6wEwcd5SLVLq5mm2gs43/SeKZg/drd4dTcWF5X6BhiU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777501808; c=relaxed/simple; bh=MmHDsAMZYMXgY8MGklEdTKgGz7VWFYW7BvgJ0ItBfcw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ir0jVmu3Iet9X3E9M6nCien0/QhIDfup0hfLDINxtsgWaUTuMHW9w15MX4XRkMyDLcx3RaK1kLEjjrJtOUPW/3wZTAeZBT31+EEXknaqgopcscSR4U60K2g+Q/F8JrnO8LSZohWOg76GiOb53/DfVtxcr/hsSyB/M9ODvBYuMng= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tA2LCDgz; 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="tA2LCDgz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1665DC2BCF5; Wed, 29 Apr 2026 22:30:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777501808; bh=MmHDsAMZYMXgY8MGklEdTKgGz7VWFYW7BvgJ0ItBfcw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tA2LCDgzA5g32u3eeH+S5ZnxhnhbX5UWC9jYDwWoYU+EbnwY6stHvYjaqPUTLT64/ CEBbA2I8nkCHGF15aD8z69ye6m1RQKODlMLfsu8ugY2RwHCyisJPEAEenpjaSCxO8v INZ0PP16De25iyKdUXKq/RO4rr68ifFOXGIJ+heFuAPz6sRneRx76CUzDyewCb1H8F +o5Ogi6qLEuoM6xCm3vUazQwxBykZSnx2ajtfgKdlaptcpwe7oPR4UZ0xST4JF5gwx ZFhVkAOxuGsCkavJjBV3L33wBwGEu6i2AdOZYGVmKXvXCVHKuhtRRjh0xiXHrHvV45 jNiG7HVUImWjA== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org, bpf@vger.kernel.org, john.fastabend@gmail.com, sd@queasysnail.net, linux-kselftest@vger.kernel.org, Jakub Kicinski , andrii@kernel.org, eddyz87@gmail.com, ast@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, memxor@gmail.com, song@kernel.org, yonghong.song@linux.dev, jolsa@kernel.org, shuah@kernel.org, jiayuan.chen@linux.dev, isolodrai@meta.com Subject: [PATCH net 7/7] selftests: bpf: cover tls_sw_sendmsg UAF after bpf_exec_tx_verdict split Date: Wed, 29 Apr 2026 15:29:44 -0700 Message-ID: <20260429222944.2139041-8-kuba@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260429222944.2139041-1-kuba@kernel.org> References: <20260429222944.2139041-1-kuba@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add a regression test for the use-after-free in tls_sw_sendmsg_locked() where the cached msg_pl pointer becomes stale after bpf_exec_tx_verdict() returns -ENOSPC: tls_push_record() may have called tls_split_open_record() which replaces ctx->open_rec and frees the old record, but the caller still dereferences msg_pl->cork_bytes. Reusing prog_sk_policy with apply_bytes=1000 + cork_bytes=800, a single 1500-byte send on a kTLS TX socket in a sockmap drives the split-and-free path. Without the fix, KASAN reports slab-use-after-free in tls_sw_sendmsg and the kernel hangs; with the fix the test completes cleanly. Signed-off-by: Jakub Kicinski --- CC: andrii@kernel.org CC: eddyz87@gmail.com CC: ast@kernel.org CC: daniel@iogearbox.net CC: martin.lau@linux.dev CC: memxor@gmail.com CC: song@kernel.org CC: yonghong.song@linux.dev CC: jolsa@kernel.org CC: shuah@kernel.org CC: john.fastabend@gmail.com CC: jiayuan.chen@linux.dev CC: isolodrai@meta.com CC: bpf@vger.kernel.org CC: linux-kselftest@vger.kernel.org --- .../selftests/bpf/prog_tests/sockmap_ktls.c | 56 +++++++++++++++++++ .../selftests/bpf/progs/test_sockmap_ktls.c | 2 + 2 files changed, 58 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c b/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c index 8ab7f4cdc614..d0bc8d39893a 100644 --- a/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c @@ -404,6 +404,60 @@ static void test_sockmap_ktls_tx_pop(int family, int sotype) test_sockmap_ktls__destroy(skel); } +static void test_sockmap_ktls_tx_apply_cork_uaf(int family, int sotype) +{ + int c = -1, p = -1, one = 1, prog_fd, map_fd; + struct test_sockmap_ktls *skel; + char buf[1500]; + ssize_t n; + int err; + + skel = test_sockmap_ktls__open_and_load(); + if (!ASSERT_TRUE(skel, "open ktls skel")) + return; + + err = create_pair(family, sotype, &c, &p); + if (!ASSERT_OK(err, "create_pair()")) + goto out; + + prog_fd = bpf_program__fd(skel->progs.prog_sk_policy); + map_fd = bpf_map__fd(skel->maps.sock_map); + + err = bpf_prog_attach(prog_fd, map_fd, BPF_SK_MSG_VERDICT, 0); + if (!ASSERT_OK(err, "bpf_prog_attach sk msg")) + goto out; + + err = bpf_map_update_elem(map_fd, &one, &c, BPF_NOEXIST); + if (!ASSERT_OK(err, "bpf_map_update_elem(c)")) + goto out; + + /* apply_bytes < send drives tls_split_open_record(); cork_bytes > + * remaining returns -ENOSPC after the split frees the old rec + */ + skel->bss->apply_bytes = 1000; + skel->bss->cork_byte = 800; + + err = init_ktls_pairs(c, p); + if (!ASSERT_OK(err, "init_ktls_pairs(c, p)")) + goto out; + + memset(buf, 'A', sizeof(buf)); + n = send(c, buf, sizeof(buf), MSG_DONTWAIT); + if (n < 0) + ASSERT_TRUE(errno == ENOSPC || errno == EAGAIN, "send errno"); + + n = send(c, buf, sizeof(buf), MSG_DONTWAIT); + if (n < 0) + ASSERT_TRUE(errno == ENOSPC || errno == EAGAIN, "send errno"); + +out: + if (c != -1) + close(c); + if (p != -1) + close(p); + test_sockmap_ktls__destroy(skel); +} + static void test_sockmap_ktls_tx_wrapped_chain(int family, int sotype) { int c = -1, p = -1, one = 1, prog_fd, map_fd; @@ -512,6 +566,8 @@ static void run_ktls_test(int family, int sotype) test_sockmap_ktls_tx_pop(family, sotype); if (test__start_subtest("tls tx wrapped sg chain")) test_sockmap_ktls_tx_wrapped_chain(family, sotype); + if (test__start_subtest("tls tx apply cork uaf")) + test_sockmap_ktls_tx_apply_cork_uaf(family, sotype); } void test_sockmap_ktls(void) diff --git a/tools/testing/selftests/bpf/progs/test_sockmap_ktls.c b/tools/testing/selftests/bpf/progs/test_sockmap_ktls.c index 18de4d7cd816..b34f0c0f9f83 100644 --- a/tools/testing/selftests/bpf/progs/test_sockmap_ktls.c +++ b/tools/testing/selftests/bpf/progs/test_sockmap_ktls.c @@ -20,6 +20,8 @@ struct { SEC("sk_msg") int prog_sk_policy(struct sk_msg_md *msg) { + if (apply_bytes > 0) + bpf_msg_apply_bytes(msg, apply_bytes); if (cork_byte > 0) bpf_msg_cork_bytes(msg, cork_byte); if (push_start > 0 && push_end > 0) -- 2.54.0