The 5 added tests are copies of the already existing tests in the same file, but changed to use R3 instead of an immediate 0. Signed-off-by: Cupertino Miranda Cc: David Faust Cc: Jose Marchesi Cc: Elena Zannoni --- .../bpf/progs/verifier_jeq_infer_not_null.c | 187 ++++++++++++++++++ 1 file changed, 187 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/verifier_jeq_infer_not_null.c b/tools/testing/selftests/bpf/progs/verifier_jeq_infer_not_null.c index bf16b00502f2..6253d48566da 100644 --- a/tools/testing/selftests/bpf/progs/verifier_jeq_infer_not_null.c +++ b/tools/testing/selftests/bpf/progs/verifier_jeq_infer_not_null.c @@ -210,4 +210,191 @@ l0_%=: /* return 0; */ \ : __clobber_all); } +/* All the functions below do the same as above but compare with a register + * instead of the immediate 0. + */ +SEC("cgroup/skb") +__description("jne/jeq with register infer not null, PTR_TO_SOCKET_OR_NULL -> PTR_TO_SOCKET for JNE false branch") +__success __failure_unpriv __msg_unpriv("R7 pointer comparison") +__retval(0) +__naked void socket_for_jne_false_branch_register(void) +{ + asm volatile (" \ + r3 = 0; \ + /* r6 = skb->sk; */ \ + r6 = *(u64*)(r1 + %[__sk_buff_sk]); \ + /* if (r6 == r3) return 0; */ \ + if r6 == r3 goto l0_%=; \ + /* r7 = sk_fullsock(skb); */ \ + r1 = r6; \ + call %[bpf_sk_fullsock]; \ + r7 = r0; \ + /* r0 = sk_fullsock(skb); */ \ + r1 = r6; \ + call %[bpf_sk_fullsock]; \ + r3 = 0; \ + /* if (r0 == null) return 0; */ \ + if r0 == r3 goto l0_%=; \ + /* if (r0 == r7) r0 = *(r7->type); */ \ + if r0 != r7 goto l0_%=; /* Use ! JNE ! */\ + r0 = *(u32*)(r7 + %[bpf_sock_type]); \ +l0_%=: /* return 0 */ \ + r0 = 0; \ + exit; \ +" : + : __imm(bpf_sk_fullsock), + __imm_const(__sk_buff_sk, offsetof(struct __sk_buff, sk)), + __imm_const(bpf_sock_type, offsetof(struct bpf_sock, type)) + : __clobber_all); +} + +SEC("cgroup/skb") +__description("jne/jeq with register infer not null, PTR_TO_SOCKET_OR_NULL unchanged for JNE true branch") +__failure __msg("R7 invalid mem access 'sock_or_null'") +__failure_unpriv __msg_unpriv("R7 pointer comparison") +__naked void unchanged_for_jne_true_branch_register(void) +{ + asm volatile (" \ + r3 = 0; \ + /* r6 = skb->sk */ \ + r6 = *(u64*)(r1 + %[__sk_buff_sk]); \ + /* if (r6 == r3) return 0; */ \ + if r6 == r3 goto l0_%=; \ + /* r7 = sk_fullsock(skb); */ \ + r1 = r6; \ + call %[bpf_sk_fullsock]; \ + r7 = r0; \ + /* r0 = sk_fullsock(skb); */ \ + r1 = r6; \ + call %[bpf_sk_fullsock]; \ + /* if (r0 == null) return 0; */ \ + if r0 != 0 goto l0_%=; \ + /* if (r0 == r7) return 0; */ \ + if r0 != r7 goto l1_%=; /* Use ! JNE ! */\ + goto l0_%=; \ +l1_%=: /* r0 = *(r7->type); */ \ + r0 = *(u32*)(r7 + %[bpf_sock_type]); \ +l0_%=: /* return 0 */ \ + r0 = 0; \ + exit; \ +" : + : __imm(bpf_sk_fullsock), + __imm_const(__sk_buff_sk, offsetof(struct __sk_buff, sk)), + __imm_const(bpf_sock_type, offsetof(struct bpf_sock, type)) + : __clobber_all); +} + +SEC("cgroup/skb") +__description("jne/jeq with register infer not null, PTR_TO_SOCKET_OR_NULL -> PTR_TO_SOCKET for JEQ true branch") +__success __failure_unpriv __msg_unpriv("R7 pointer comparison") +__retval(0) +__naked void socket_for_jeq_true_branch_register(void) +{ + asm volatile (" \ + /* r6 = skb->sk; */ \ + r6 = *(u64*)(r1 + %[__sk_buff_sk]); \ + /* if (r6 == null) return 0; */ \ + if r6 == 0 goto l0_%=; \ + /* r7 = sk_fullsock(skb); */ \ + r1 = r6; \ + call %[bpf_sk_fullsock]; \ + r7 = r0; \ + /* r0 = sk_fullsock(skb); */ \ + r1 = r6; \ + call %[bpf_sk_fullsock]; \ + r3 = 0; \ + /* if (r0 == r3) return 0; */ \ + if r0 == r3 goto l0_%=; \ + /* if (r0 != r7) return 0; */ \ + if r0 == r7 goto l1_%=; /* Use ! JEQ ! */\ + goto l0_%=; \ +l1_%=: /* r0 = *(r7->type); */ \ + r0 = *(u32*)(r7 + %[bpf_sock_type]); \ +l0_%=: /* return 0; */ \ + r0 = 0; \ + exit; \ +" : + : __imm(bpf_sk_fullsock), + __imm_const(__sk_buff_sk, offsetof(struct __sk_buff, sk)), + __imm_const(bpf_sock_type, offsetof(struct bpf_sock, type)) + : __clobber_all); +} + +SEC("cgroup/skb") +__description("jne/jeq with register infer not null, PTR_TO_SOCKET_OR_NULL unchanged for JEQ false branch") +__failure __msg("R7 invalid mem access 'sock_or_null'") +__failure_unpriv __msg_unpriv("R7 pointer comparison") +__naked void unchanged_for_jeq_false_branch_register(void) +{ + asm volatile (" \ + r3 = 0; \ + /* r6 = skb->sk; */ \ + r6 = *(u64*)(r1 + %[__sk_buff_sk]); \ + /* if (r6 == r3) return 0; */ \ + r3 = 0; \ + if r6 == r3 goto l0_%=; \ + /* r7 = sk_fullsock(skb); */ \ + r1 = r6; \ + call %[bpf_sk_fullsock]; \ + r7 = r0; \ + /* r0 = sk_fullsock(skb); */ \ + r1 = r6; \ + call %[bpf_sk_fullsock]; \ + r3 = 0; \ + /* if (r0 == r3) return 0; */ \ + r3 = 0; \ + if r0 == r3 goto l0_%=; \ + /* if (r0 != r7) r0 = *(r7->type); */ \ + if r0 == r7 goto l0_%=; /* Use ! JEQ ! */\ + r0 = *(u32*)(r7 + %[bpf_sock_type]); \ +l0_%=: /* return 0; */ \ + r0 = 0; \ + exit; \ +" : + : __imm(bpf_sk_fullsock), + __imm_const(__sk_buff_sk, offsetof(struct __sk_buff, sk)), + __imm_const(bpf_sock_type, offsetof(struct bpf_sock, type)) + : __clobber_all); +} + +SEC("xdp") +__description("jne/jeq with register infer not null, PTR_TO_MAP_VALUE_OR_NULL -> PTR_TO_MAP_VALUE") +__success __retval(0) +__naked void null_ptr_to_map_value_register(void) +{ + asm volatile (" \ + /* r9 = &some stack to use as key */ \ + r1 = 0; \ + *(u32*)(r10 - 8) = r1; \ + r9 = r10; \ + r9 += -8; \ + /* r8 = process local map */ \ + r8 = %[map_xskmap] ll; \ + /* r6 = map_lookup_elem(r8, r9); */ \ + r1 = r8; \ + r2 = r9; \ + call %[bpf_map_lookup_elem]; \ + r6 = r0; \ + /* r7 = map_lookup_elem(r8, r9); */ \ + r1 = r8; \ + r2 = r9; \ + call %[bpf_map_lookup_elem]; \ + r3 = 0; \ + r7 = r0; \ + /* if (r6 == r3) return 0; */ \ + if r6 == r3 goto l0_%=; \ + /* if (r6 != r7) return 0; */ \ + if r6 != r7 goto l0_%=; \ + /* read *r7; */ \ + r0 = *(u32*)(r7 + %[bpf_xdp_sock_queue_id]); \ +l0_%=: /* return 0; */ \ + r0 = 0; \ + exit; \ +" : + : __imm(bpf_map_lookup_elem), + __imm_addr(map_xskmap), + __imm_const(bpf_xdp_sock_queue_id, offsetof(struct bpf_xdp_sock, queue_id)) + : __clobber_all); +} + char _license[] SEC("license") = "GPL"; -- 2.47.3