From e523102cb719cbad1673b6aa2a4d5c1fa6f13799 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 13 Dec 2021 22:25:23 +0000 Subject: [PATCH] bpf, selftests: Update test case for atomic cmpxchg on r0 with pointer Fix up unprivileged test case results for 'Dest pointer in r0' verifier tests given they now need to reject R0 containing a pointer value, and add a couple of new related ones with 32bit cmpxchg as well. root@foo:~/bpf/tools/testing/selftests/bpf# ./test_verifier #0/u invalid and of negative number OK #0/p invalid and of negative number OK [...] #1268/p XDP pkt read, pkt_meta' <= pkt_data, bad access 1 OK #1269/p XDP pkt read, pkt_meta' <= pkt_data, bad access 2 OK #1270/p XDP pkt read, pkt_data <= pkt_meta', good access OK #1271/p XDP pkt read, pkt_data <= pkt_meta', bad access 1 OK #1272/p XDP pkt read, pkt_data <= pkt_meta', bad access 2 OK Summary: 1900 PASSED, 0 SKIPPED, 0 FAILED Acked-by: Brendan Jackman Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- .../selftests/bpf/verifier/atomic_cmpxchg.c | 67 +++++++++++++++++++++- 1 file changed, 65 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c b/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c index 0ffc69f..b39665f 100644 --- a/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c +++ b/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c @@ -138,6 +138,8 @@ BPF_EXIT_INSN(), }, .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 leaks addr into mem", }, { "Dest pointer in r0 - succeed", @@ -157,7 +159,7 @@ }, .result = ACCEPT, .result_unpriv = REJECT, - .errstr_unpriv = "leaking pointer from stack off -8", + .errstr_unpriv = "R0 leaks addr into mem", }, { "Dest pointer in r0 - succeed, check 2", @@ -178,5 +180,66 @@ }, .result = ACCEPT, .result_unpriv = REJECT, - .errstr_unpriv = "R5 leaks addr into mem", + .errstr_unpriv = "R0 leaks addr into mem", +}, +{ + "Dest pointer in r0 - succeed, check 3", + .insns = { + /* r0 = &val */ + BPF_MOV64_REG(BPF_REG_0, BPF_REG_10), + /* val = r0; */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8), + /* r5 = &val */ + BPF_MOV64_REG(BPF_REG_5, BPF_REG_10), + /* r0 = atomic_cmpxchg(&val, r0, r5); */ + BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_5, -8), + /* exit(0); */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid size of register fill", + .errstr_unpriv = "R0 leaks addr into mem", +}, +{ + "Dest pointer in r0 - succeed, check 4", + .insns = { + /* r0 = &val */ + BPF_MOV32_REG(BPF_REG_0, BPF_REG_10), + /* val = r0; */ + BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -8), + /* r5 = &val */ + BPF_MOV32_REG(BPF_REG_5, BPF_REG_10), + /* r0 = atomic_cmpxchg(&val, r0, r5); */ + BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_5, -8), + /* r1 = *r10 */ + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_10, -8), + /* exit(0); */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R10 partial copy of pointer", +}, +{ + "Dest pointer in r0 - succeed, check 5", + .insns = { + /* r0 = &val */ + BPF_MOV32_REG(BPF_REG_0, BPF_REG_10), + /* val = r0; */ + BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -8), + /* r5 = &val */ + BPF_MOV32_REG(BPF_REG_5, BPF_REG_10), + /* r0 = atomic_cmpxchg(&val, r0, r5); */ + BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_5, -8), + /* r1 = *r0 */ + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, -8), + /* exit(0); */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "R0 invalid mem access", + .errstr_unpriv = "R10 partial copy of pointer", }, -- 2.7.4