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authorPaolo Bonzini <pbonzini@redhat.com>2023-02-15 12:33:28 -0500
committerPaolo Bonzini <pbonzini@redhat.com>2023-02-15 12:33:28 -0500
commit33436335e93a1788a58443fc99c5ab320ce4b9d9 (patch)
treed92f88768c8dbd00f8b65164f47a8a091768b95a /tools/testing/selftests/bpf/verifier/search_pruning.c
parent27b025ebb0f6092d5c0a88de2ab73545bc1c496e (diff)
parentc39cea6f38eefe356d64d0bc1e1f2267e282cdd3 (diff)
Merge tag 'kvm-riscv-6.3-1' of https://github.com/kvm-riscv/linux into HEAD
KVM/riscv changes for 6.3 - Fix wrong usage of PGDIR_SIZE to check page sizes - Fix privilege mode setting in kvm_riscv_vcpu_trap_redirect() - Redirect illegal instruction traps to guest - SBI PMU support for guest
Diffstat (limited to 'tools/testing/selftests/bpf/verifier/search_pruning.c')
-rw-r--r--tools/testing/selftests/bpf/verifier/search_pruning.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/verifier/search_pruning.c b/tools/testing/selftests/bpf/verifier/search_pruning.c
index 68b14fdfebdb..d63fd8991b03 100644
--- a/tools/testing/selftests/bpf/verifier/search_pruning.c
+++ b/tools/testing/selftests/bpf/verifier/search_pruning.c
@@ -225,3 +225,39 @@
.result_unpriv = ACCEPT,
.insn_processed = 15,
},
+/* The test performs a conditional 64-bit write to a stack location
+ * fp[-8], this is followed by an unconditional 8-bit write to fp[-8],
+ * then data is read from fp[-8]. This sequence is unsafe.
+ *
+ * The test would be mistakenly marked as safe w/o dst register parent
+ * preservation in verifier.c:copy_register_state() function.
+ *
+ * Note the usage of BPF_F_TEST_STATE_FREQ to force creation of the
+ * checkpoint state after conditional 64-bit assignment.
+ */
+{
+ "write tracking and register parent chain bug",
+ .insns = {
+ /* r6 = ktime_get_ns() */
+ BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
+ /* r0 = ktime_get_ns() */
+ BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+ /* if r0 > r6 goto +1 */
+ BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_6, 1),
+ /* *(u64 *)(r10 - 8) = 0xdeadbeef */
+ BPF_ST_MEM(BPF_DW, BPF_REG_FP, -8, 0xdeadbeef),
+ /* r1 = 42 */
+ BPF_MOV64_IMM(BPF_REG_1, 42),
+ /* *(u8 *)(r10 - 8) = r1 */
+ BPF_STX_MEM(BPF_B, BPF_REG_FP, BPF_REG_1, -8),
+ /* r2 = *(u64 *)(r10 - 8) */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_FP, -8),
+ /* exit(0) */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .flags = BPF_F_TEST_STATE_FREQ,
+ .errstr = "invalid read from stack off -8+1 size 8",
+ .result = REJECT,
+},