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

Alexei Starovoitov says:

====================
pull-request: bpf 2019-03-24

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

The main changes are:

1) libbpf verision fix up from Daniel.

2) fix liveness propagation from Jakub.

3) fix verbose print of refcounted regs from Martin.

4) fix for large map allocations from Martynas.

5) fix use after free in sanitize_ptr_alu from Xu.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 38 insertions, 19 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 62f6bced3a3c..afca36f53c49 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -136,21 +136,29 @@ static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
 
 void *bpf_map_area_alloc(size_t size, int numa_node)
 {
-	/* We definitely need __GFP_NORETRY, so OOM killer doesn't
-	 * trigger under memory pressure as we really just want to
-	 * fail instead.
+	/* We really just want to fail instead of triggering OOM killer
+	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
+	 * which is used for lower order allocation requests.
+	 *
+	 * It has been observed that higher order allocation requests done by
+	 * vmalloc with __GFP_NORETRY being set might fail due to not trying
+	 * to reclaim memory from the page cache, thus we set
+	 * __GFP_RETRY_MAYFAIL to avoid such situations.
 	 */
-	const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO;
+
+	const gfp_t flags = __GFP_NOWARN | __GFP_ZERO;
 	void *area;
 
 	if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
-		area = kmalloc_node(size, GFP_USER | flags, numa_node);
+		area = kmalloc_node(size, GFP_USER | __GFP_NORETRY | flags,
+				    numa_node);
 		if (area != NULL)
 			return area;
 	}
 
-	return __vmalloc_node_flags_caller(size, numa_node, GFP_KERNEL | flags,
-					   __builtin_return_address(0));
+	return __vmalloc_node_flags_caller(size, numa_node,
+					   GFP_KERNEL | __GFP_RETRY_MAYFAIL |
+					   flags, __builtin_return_address(0));
 }
 
 void bpf_map_area_free(void *area)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 86f9cd5d1c4e..fd502c1f71eb 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -352,6 +352,14 @@ static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg)
 		map_value_has_spin_lock(reg->map_ptr);
 }
 
+static bool reg_type_may_be_refcounted_or_null(enum bpf_reg_type type)
+{
+	return type == PTR_TO_SOCKET ||
+		type == PTR_TO_SOCKET_OR_NULL ||
+		type == PTR_TO_TCP_SOCK ||
+		type == PTR_TO_TCP_SOCK_OR_NULL;
+}
+
 static bool arg_type_may_be_refcounted(enum bpf_arg_type type)
 {
 	return type == ARG_PTR_TO_SOCK_COMMON;
@@ -451,8 +459,9 @@ static void print_verifier_state(struct bpf_verifier_env *env,
 			if (t == PTR_TO_STACK)
 				verbose(env, ",call_%d", func(env, reg)->callsite);
 		} else {
-			verbose(env, "(id=%d ref_obj_id=%d", reg->id,
-				reg->ref_obj_id);
+			verbose(env, "(id=%d", reg->id);
+			if (reg_type_may_be_refcounted_or_null(t))
+				verbose(env, ",ref_obj_id=%d", reg->ref_obj_id);
 			if (t != SCALAR_VALUE)
 				verbose(env, ",off=%d", reg->off);
 			if (type_is_pkt_pointer(t))
@@ -3372,7 +3381,7 @@ do_sim:
 		*dst_reg = *ptr_reg;
 	}
 	ret = push_stack(env, env->insn_idx + 1, env->insn_idx, true);
-	if (!ptr_is_dst_reg)
+	if (!ptr_is_dst_reg && ret)
 		*dst_reg = tmp;
 	return !ret ? -EFAULT : 0;
 }
@@ -6069,15 +6078,17 @@ static int propagate_liveness(struct bpf_verifier_env *env,
 	}
 	/* Propagate read liveness of registers... */
 	BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG);
-	/* We don't need to worry about FP liveness because it's read-only */
-	for (i = 0; i < BPF_REG_FP; i++) {
-		if (vparent->frame[vparent->curframe]->regs[i].live & REG_LIVE_READ)
-			continue;
-		if (vstate->frame[vstate->curframe]->regs[i].live & REG_LIVE_READ) {
-			err = mark_reg_read(env, &vstate->frame[vstate->curframe]->regs[i],
-					    &vparent->frame[vstate->curframe]->regs[i]);
-			if (err)
-				return err;
+	for (frame = 0; frame <= vstate->curframe; frame++) {
+		/* We don't need to worry about FP liveness, it's read-only */
+		for (i = frame < vstate->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++) {
+			if (vparent->frame[frame]->regs[i].live & REG_LIVE_READ)
+				continue;
+			if (vstate->frame[frame]->regs[i].live & REG_LIVE_READ) {
+				err = mark_reg_read(env, &vstate->frame[frame]->regs[i],
+						    &vparent->frame[frame]->regs[i]);
+				if (err)
+					return err;
+			}
 		}
 	}