From: Daniel Borkmann daniel@iogearbox.net
mainline inclusion from mainline-v5.17-rc1 commit 37c8d4807d1b8b521b30310dce97f6695dc2c2c6 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4WT90 CVE: CVE-2021-4204
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Add two tests, one which asserts that ring buffer memory can be passed to other helpers for populating its entry area, and another one where verifier rejects different type of memory passed to bpf_ringbuf_submit().
Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: John Fastabend john.fastabend@gmail.com Acked-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Pu Lehui pulehui@huawei.com Reviewed-by: Kuohai Xu xukuohai@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- .../testing/selftests/bpf/prog_tests/d_path.c | 14 ++++++++ .../bpf/progs/test_d_path_check_types.c | 32 ++++++++++++++++++ .../testing/selftests/bpf/verifier/ringbuf.c | 33 ++++++++++++++++++- 3 files changed, 78 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/progs/test_d_path_check_types.c
diff --git a/tools/testing/selftests/bpf/prog_tests/d_path.c b/tools/testing/selftests/bpf/prog_tests/d_path.c index 8c8bc495e7f4..85f1386a97e6 100644 --- a/tools/testing/selftests/bpf/prog_tests/d_path.c +++ b/tools/testing/selftests/bpf/prog_tests/d_path.c @@ -10,6 +10,7 @@
#include "test_d_path.skel.h" #include "test_d_path_check_rdonly_mem.skel.h" +#include "test_d_path_check_types.skel.h"
static int duration;
@@ -167,6 +168,16 @@ static void test_d_path_check_rdonly_mem(void) test_d_path_check_rdonly_mem__destroy(skel); }
+static void test_d_path_check_types(void) +{ + struct test_d_path_check_types *skel; + + skel = test_d_path_check_types__open_and_load(); + CHECK(skel, "skel_open", "unexpected_load_passing_wrong_type"); + + test_d_path_check_types__destroy(skel); +} + void test_d_path(void) { if (test__start_subtest("basic")) @@ -174,4 +185,7 @@ void test_d_path(void)
if (test__start_subtest("check_rdonly_mem")) test_d_path_check_rdonly_mem(); + + if (test__start_subtest("check_alloc_mem")) + test_d_path_check_types(); } diff --git a/tools/testing/selftests/bpf/progs/test_d_path_check_types.c b/tools/testing/selftests/bpf/progs/test_d_path_check_types.c new file mode 100644 index 000000000000..7e02b7361307 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_d_path_check_types.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +extern const int bpf_prog_active __ksym; + +struct { + __uint(type, BPF_MAP_TYPE_RINGBUF); + __uint(max_entries, 1 << 12); +} ringbuf SEC(".maps"); + +SEC("fentry/security_inode_getattr") +int BPF_PROG(d_path_check_rdonly_mem, struct path *path, struct kstat *stat, + __u32 request_mask, unsigned int query_flags) +{ + void *active; + u32 cpu; + + cpu = bpf_get_smp_processor_id(); + active = (void *)bpf_per_cpu_ptr(&bpf_prog_active, cpu); + if (active) { + /* FAIL here! 'active' points to 'regular' memory. It + * cannot be submitted to ring buffer. + */ + bpf_ringbuf_submit(active, 0); + } + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/verifier/ringbuf.c b/tools/testing/selftests/bpf/verifier/ringbuf.c index 68cae6947cc4..b64d33e4833c 100644 --- a/tools/testing/selftests/bpf/verifier/ringbuf.c +++ b/tools/testing/selftests/bpf/verifier/ringbuf.c @@ -28,7 +28,7 @@ }, .fixup_map_ringbuf = { 1 }, .result = REJECT, - .errstr = "dereference of modified mem ptr R1", + .errstr = "dereference of modified alloc_mem ptr R1", }, { "ringbuf: invalid reservation offset 2", @@ -62,3 +62,34 @@ .result = REJECT, .errstr = "R7 min value is outside of the allowed memory range", }, +{ + "ringbuf: check passing rb mem to helpers", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + /* reserve 8 byte ringbuf memory */ + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_MOV64_IMM(BPF_REG_2, 8), + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_ringbuf_reserve), + BPF_MOV64_REG(BPF_REG_7, BPF_REG_0), + /* check whether the reservation was successful */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_EXIT_INSN(), + /* pass allocated ring buffer memory to fib lookup */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_0), + BPF_MOV64_IMM(BPF_REG_3, 8), + BPF_MOV64_IMM(BPF_REG_4, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_fib_lookup), + /* submit the ringbuf memory */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_7), + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_ringbuf_submit), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_ringbuf = { 2 }, + .prog_type = BPF_PROG_TYPE_XDP, + .result = ACCEPT, +},