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| author | Daniel Borkmann <daniel@iogearbox.net> | 2022-01-10 14:44:18 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-01-19 01:21:49 +0100 |
| commit | 722e4db3ae0d52b2e3801280afbe19cf2d188e91 (patch) | |
| tree | 97b076a0a1cd73587d5969a88fd49c89a4df066d /tools | |
| parent | bpf: Fix ringbuf memory type confusion when passing to helpers (diff) | |
| download | linux-722e4db3ae0d52b2e3801280afbe19cf2d188e91.tar.xz linux-722e4db3ae0d52b2e3801280afbe19cf2d188e91.zip | |
bpf, selftests: Add various ringbuf tests with invalid offset
Assert that the verifier is rejecting invalid offsets on the ringbuf entries:
# ./test_verifier | grep ring
#947/u ringbuf: invalid reservation offset 1 OK
#947/p ringbuf: invalid reservation offset 1 OK
#948/u ringbuf: invalid reservation offset 2 OK
#948/p ringbuf: invalid reservation offset 2 OK
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/ringbuf.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/verifier/ringbuf.c b/tools/testing/selftests/bpf/verifier/ringbuf.c new file mode 100644 index 000000000000..68cae6947cc4 --- /dev/null +++ b/tools/testing/selftests/bpf/verifier/ringbuf.c @@ -0,0 +1,64 @@ +{ + "ringbuf: invalid reservation offset 1", + .insns = { + /* 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), + /* store a pointer to the reserved memory in R6 */ + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + /* check whether the reservation was successful */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 7), + /* spill R6(mem) into the stack */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -8), + /* fill it back in R7 */ + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_10, -8), + /* should be able to access *(R7) = 0 */ + BPF_ST_MEM(BPF_DW, BPF_REG_7, 0, 0), + /* submit the reserved ringbuf memory */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_7), + /* add invalid offset to reserved ringbuf memory */ + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 0xcafe), + 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 = { 1 }, + .result = REJECT, + .errstr = "dereference of modified mem ptr R1", +}, +{ + "ringbuf: invalid reservation offset 2", + .insns = { + /* 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), + /* store a pointer to the reserved memory in R6 */ + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + /* check whether the reservation was successful */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 7), + /* spill R6(mem) into the stack */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -8), + /* fill it back in R7 */ + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_10, -8), + /* add invalid offset to reserved ringbuf memory */ + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 0xcafe), + /* should be able to access *(R7) = 0 */ + BPF_ST_MEM(BPF_DW, BPF_REG_7, 0, 0), + /* submit the reserved 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 = { 1 }, + .result = REJECT, + .errstr = "R7 min value is outside of the allowed memory range", +}, |