Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2021-06-15

The following pull-request contains BPF updates for your *net* tree.

We've added 5 non-merge commits during the last 11 day(s) which contain
a total of 10 files changed, 115 insertions(+), 16 deletions(-).

The main changes are:

1) Fix marking incorrect umem ring as done in libbpf's
   xsk_socket__create_shared() helper, from Kev Jackson.

2) Fix oob leakage under a spectre v1 type confusion
   attack, from Daniel Borkmann.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

kernel/bpf/verifier.c

@@ -6483,6 +6483,27 @@ struct bpf_sanitize_info {
 	bool mask_to_left;
 };
 
+static struct bpf_verifier_state *
+sanitize_speculative_path(struct bpf_verifier_env *env,
+			  const struct bpf_insn *insn,
+			  u32 next_idx, u32 curr_idx)
+{
+	struct bpf_verifier_state *branch;
+	struct bpf_reg_state *regs;
+
+	branch = push_stack(env, next_idx, curr_idx, true);
+	if (branch && insn) {
+		regs = branch->frame[branch->curframe]->regs;
+		if (BPF_SRC(insn->code) == BPF_K) {
+			mark_reg_unknown(env, regs, insn->dst_reg);
+		} else if (BPF_SRC(insn->code) == BPF_X) {
+			mark_reg_unknown(env, regs, insn->dst_reg);
+			mark_reg_unknown(env, regs, insn->src_reg);
+		}
+	}
+	return branch;
+}
+
 static int sanitize_ptr_alu(struct bpf_verifier_env *env,
 			    struct bpf_insn *insn,
 			    const struct bpf_reg_state *ptr_reg,
@@ -6566,12 +6587,26 @@ static int sanitize_ptr_alu(struct bpf_verifier_env *env,
 		tmp = *dst_reg;
 		*dst_reg = *ptr_reg;
 	}
-	ret = push_stack(env, env->insn_idx + 1, env->insn_idx, true);
+	ret = sanitize_speculative_path(env, NULL, env->insn_idx + 1,
+					env->insn_idx);
 	if (!ptr_is_dst_reg && ret)
 		*dst_reg = tmp;
 	return !ret ? REASON_STACK : 0;
 }
 
+static void sanitize_mark_insn_seen(struct bpf_verifier_env *env)
+{
+	struct bpf_verifier_state *vstate = env->cur_state;
+
+	/* If we simulate paths under speculation, we don't update the
+	 * insn as 'seen' such that when we verify unreachable paths in
+	 * the non-speculative domain, sanitize_dead_code() can still
+	 * rewrite/sanitize them.
+	 */
+	if (!vstate->speculative)
+		env->insn_aux_data[env->insn_idx].seen = env->pass_cnt;
+}
+
 static int sanitize_err(struct bpf_verifier_env *env,
 			const struct bpf_insn *insn, int reason,
 			const struct bpf_reg_state *off_reg,
@@ -8750,14 +8785,28 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
 		if (err)
 			return err;
 	}
+
 	if (pred == 1) {
-		/* only follow the goto, ignore fall-through */
+		/* Only follow the goto, ignore fall-through. If needed, push
+		 * the fall-through branch for simulation under speculative
+		 * execution.
+		 */
+		if (!env->bypass_spec_v1 &&
+		    !sanitize_speculative_path(env, insn, *insn_idx + 1,
+					       *insn_idx))
+			return -EFAULT;
 		*insn_idx += insn->off;
 		return 0;
 	} else if (pred == 0) {
-		/* only follow fall-through branch, since
-		 * that's where the program will go
-		 */
+		/* Only follow the fall-through branch, since that's where the
+		 * program will go. If needed, push the goto branch for
+		 * simulation under speculative execution.
+		 */
+		if (!env->bypass_spec_v1 &&
+		    !sanitize_speculative_path(env, insn,
+					       *insn_idx + insn->off + 1,
+					       *insn_idx))
+			return -EFAULT;
 		return 0;
 	}
 
@@ -10630,7 +10679,7 @@ static int do_check(struct bpf_verifier_env *env)
 		}
 
 		regs = cur_regs(env);
-		env->insn_aux_data[env->insn_idx].seen = env->pass_cnt;
+		sanitize_mark_insn_seen(env);
 		prev_insn_idx = env->insn_idx;
 
 		if (class == BPF_ALU || class == BPF_ALU64) {
@@ -10857,7 +10906,7 @@ static int do_check(struct bpf_verifier_env *env)
 					return err;
 
 				env->insn_idx++;
-				env->insn_aux_data[env->insn_idx].seen = env->pass_cnt;
+				sanitize_mark_insn_seen(env);
 			} else {
 				verbose(env, "invalid BPF_LD mode\n");
 				return -EINVAL;
@@ -11366,6 +11415,7 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env,
 {
 	struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data;
 	struct bpf_insn *insn = new_prog->insnsi;
+	u32 old_seen = old_data[off].seen;
 	u32 prog_len;
 	int i;
 
@@ -11386,7 +11436,8 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env,
 	memcpy(new_data + off + cnt - 1, old_data + off,
 	       sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1));
 	for (i = off; i < off + cnt - 1; i++) {
-		new_data[i].seen = env->pass_cnt;
+		/* Expand insni[off]'s seen count to the patched range. */
+		new_data[i].seen = old_seen;
 		new_data[i].zext_dst = insn_has_def32(env, insn + i);
 	}
 	env->insn_aux_data = new_data;
@@ -12710,6 +12761,9 @@ static void free_states(struct bpf_verifier_env *env)
  * insn_aux_data was touched. These variables are compared to clear temporary
  * data from failed pass. For testing and experiments do_check_common() can be
  * run multiple times even when prior attempt to verify is unsuccessful.
+ *
+ * Note that special handling is needed on !env->bypass_spec_v1 if this is
+ * ever called outside of error path with subsequent program rejection.
  */
 static void sanitize_insn_aux_data(struct bpf_verifier_env *env)
 {

tools/lib/bpf/xsk.c

@@ -1094,7 +1094,7 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr,
 			goto out_put_ctx;
 		}
 		if (xsk->fd == umem->fd)
-			umem->rx_ring_setup_done = true;
+			umem->tx_ring_setup_done = true;
 	}
 
 	err = xsk_get_mmap_offsets(xsk->fd, &off);

tools/testing/selftests/bpf/test_verifier.c

@@ -1147,7 +1147,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
 		}
 	}
 
-	if (test->insn_processed) {
+	if (!unpriv && test->insn_processed) {
 		uint32_t insn_processed;
 		char *proc;
 

tools/testing/selftests/bpf/verifier/and.c

@@ -61,6 +61,8 @@
 	BPF_MOV64_IMM(BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R1 !read_ok",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 0
 },

tools/testing/selftests/bpf/verifier/bounds.c

@@ -508,6 +508,8 @@
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, -1),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 invalid mem access 'inv'",
+	.result_unpriv = REJECT,
 	.result = ACCEPT
 },
 {
@@ -528,6 +530,8 @@
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, -1),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 invalid mem access 'inv'",
+	.result_unpriv = REJECT,
 	.result = ACCEPT
 },
 {
@@ -569,6 +573,8 @@
 	BPF_MOV64_IMM(BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 min value is outside of the allowed memory range",
+	.result_unpriv = REJECT,
 	.fixup_map_hash_8b = { 3 },
 	.result = ACCEPT,
 },
@@ -589,6 +595,8 @@
 	BPF_MOV64_IMM(BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 min value is outside of the allowed memory range",
+	.result_unpriv = REJECT,
 	.fixup_map_hash_8b = { 3 },
 	.result = ACCEPT,
 },
@@ -609,6 +617,8 @@
 	BPF_MOV64_IMM(BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 min value is outside of the allowed memory range",
+	.result_unpriv = REJECT,
 	.fixup_map_hash_8b = { 3 },
 	.result = ACCEPT,
 },
@@ -674,6 +684,8 @@
 	BPF_MOV64_IMM(BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 min value is outside of the allowed memory range",
+	.result_unpriv = REJECT,
 	.fixup_map_hash_8b = { 3 },
 	.result = ACCEPT,
 },
@@ -695,6 +707,8 @@
 	BPF_MOV64_IMM(BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 min value is outside of the allowed memory range",
+	.result_unpriv = REJECT,
 	.fixup_map_hash_8b = { 3 },
 	.result = ACCEPT,
 },

tools/testing/selftests/bpf/verifier/dead_code.c

@@ -8,6 +8,8 @@
 	BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 10, -4),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R9 !read_ok",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 7,
 },

tools/testing/selftests/bpf/verifier/jmp32.c

@@ -87,6 +87,8 @@
 	BPF_LDX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R9 !read_ok",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 },
 {
@@ -150,6 +152,8 @@
 	BPF_LDX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R9 !read_ok",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 },
 {
@@ -213,6 +217,8 @@
 	BPF_LDX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R9 !read_ok",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 },
 {
@@ -280,6 +286,8 @@
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 invalid mem access 'inv'",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 2,
 },
@@ -348,6 +356,8 @@
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 invalid mem access 'inv'",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 2,
 },
@@ -416,6 +426,8 @@
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 invalid mem access 'inv'",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 2,
 },
@@ -484,6 +496,8 @@
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 invalid mem access 'inv'",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 2,
 },
@@ -552,6 +566,8 @@
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 invalid mem access 'inv'",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 2,
 },
@@ -620,6 +636,8 @@
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 invalid mem access 'inv'",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 2,
 },
@@ -688,6 +706,8 @@
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 invalid mem access 'inv'",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 2,
 },
@@ -756,6 +776,8 @@
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R0 invalid mem access 'inv'",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 2,
 },

tools/testing/selftests/bpf/verifier/jset.c

@@ -82,8 +82,8 @@
 	BPF_EXIT_INSN(),
 	},
 	.prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
-	.retval_unpriv = 1,
-	.result_unpriv = ACCEPT,
+	.errstr_unpriv = "R9 !read_ok",
+	.result_unpriv = REJECT,
 	.retval = 1,
 	.result = ACCEPT,
 },
@@ -141,7 +141,8 @@
 	BPF_EXIT_INSN(),
 	},
 	.prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
-	.result_unpriv = ACCEPT,
+	.errstr_unpriv = "R9 !read_ok",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 },
 {
@@ -162,6 +163,7 @@
 	BPF_EXIT_INSN(),
 	},
 	.prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
-	.result_unpriv = ACCEPT,
+	.errstr_unpriv = "R9 !read_ok",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 },

tools/testing/selftests/bpf/verifier/unpriv.c

@@ -420,6 +420,8 @@
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_7, 0),
 	BPF_EXIT_INSN(),
 	},
+	.errstr_unpriv = "R7 invalid mem access 'inv'",
+	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 0,
 },

tools/testing/selftests/bpf/verifier/value_ptr_arith.c

@@ -120,7 +120,7 @@
 	.fixup_map_array_48b = { 1 },
 	.result = ACCEPT,
 	.result_unpriv = REJECT,
-	.errstr_unpriv = "R2 tried to add from different maps, paths or scalars",
+	.errstr_unpriv = "R2 pointer comparison prohibited",
 	.retval = 0,
 },
 {
@@ -159,7 +159,8 @@
 	BPF_MOV64_IMM(BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	// fake-dead code; targeted from branch A to
-	// prevent dead code sanitization
+	// prevent dead code sanitization, rejected
+	// via branch B however
 	BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, 0),
 	BPF_MOV64_IMM(BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
@@ -167,7 +168,7 @@
 	.fixup_map_array_48b = { 1 },
 	.result = ACCEPT,
 	.result_unpriv = REJECT,
-	.errstr_unpriv = "R2 tried to add from different maps, paths or scalars",
+	.errstr_unpriv = "R0 invalid mem access 'inv'",
 	.retval = 0,
 },
 {