Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Martin KaFai Lau says:

====================
pull-request: bpf-next 2025-07-24

We've added 3 non-merge commits during the last 3 day(s) which contain
a total of 4 files changed, 40 insertions(+), 15 deletions(-).

The main changes are:

1) Improved verifier error message for incorrect narrower load from
   pointer field in ctx, from Paul Chaignon.

2) Disabled migration in nf_hook_run_bpf to address a syzbot report,
   from Kuniyuki Iwashima.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
  selftests/bpf: Test invalid narrower ctx load
  bpf: Reject narrower access to pointer ctx fields
  bpf: Disable migration in nf_hook_run_bpf().
====================

Link: https://patch.msgid.link/20250724173306.3578483-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

kernel/bpf/cgroup.c

@@ -2440,22 +2440,22 @@ static bool cg_sockopt_is_valid_access(int off, int size,
 	}
 
 	switch (off) {
-	case offsetof(struct bpf_sockopt, sk):
+	case bpf_ctx_range_ptr(struct bpf_sockopt, sk):
 		if (size != sizeof(__u64))
 			return false;
 		info->reg_type = PTR_TO_SOCKET;
 		break;
-	case offsetof(struct bpf_sockopt, optval):
+	case bpf_ctx_range_ptr(struct bpf_sockopt, optval):
 		if (size != sizeof(__u64))
 			return false;
 		info->reg_type = PTR_TO_PACKET;
 		break;
-	case offsetof(struct bpf_sockopt, optval_end):
+	case bpf_ctx_range_ptr(struct bpf_sockopt, optval_end):
 		if (size != sizeof(__u64))
 			return false;
 		info->reg_type = PTR_TO_PACKET_END;
 		break;
-	case offsetof(struct bpf_sockopt, retval):
+	case bpf_ctx_range(struct bpf_sockopt, retval):
 		if (size != size_default)
 			return false;
 		return prog->expected_attach_type == BPF_CGROUP_GETSOCKOPT;

net/core/filter.c

@@ -8699,7 +8699,7 @@ static bool bpf_skb_is_valid_access(int off, int size, enum bpf_access_type type
 		if (size != sizeof(__u64))
 			return false;
 		break;
-	case offsetof(struct __sk_buff, sk):
+	case bpf_ctx_range_ptr(struct __sk_buff, sk):
 		if (type == BPF_WRITE || size != sizeof(__u64))
 			return false;
 		info->reg_type = PTR_TO_SOCK_COMMON_OR_NULL;
@@ -9277,7 +9277,7 @@ static bool sock_addr_is_valid_access(int off, int size,
 				return false;
 		}
 		break;
-	case offsetof(struct bpf_sock_addr, sk):
+	case bpf_ctx_range_ptr(struct bpf_sock_addr, sk):
 		if (type != BPF_READ)
 			return false;
 		if (size != sizeof(__u64))
@@ -9327,17 +9327,17 @@ static bool sock_ops_is_valid_access(int off, int size,
 			if (size != sizeof(__u64))
 				return false;
 			break;
-		case offsetof(struct bpf_sock_ops, sk):
+		case bpf_ctx_range_ptr(struct bpf_sock_ops, sk):
 			if (size != sizeof(__u64))
 				return false;
 			info->reg_type = PTR_TO_SOCKET_OR_NULL;
 			break;
-		case offsetof(struct bpf_sock_ops, skb_data):
+		case bpf_ctx_range_ptr(struct bpf_sock_ops, skb_data):
 			if (size != sizeof(__u64))
 				return false;
 			info->reg_type = PTR_TO_PACKET;
 			break;
-		case offsetof(struct bpf_sock_ops, skb_data_end):
+		case bpf_ctx_range_ptr(struct bpf_sock_ops, skb_data_end):
 			if (size != sizeof(__u64))
 				return false;
 			info->reg_type = PTR_TO_PACKET_END;
@@ -9346,7 +9346,7 @@ static bool sock_ops_is_valid_access(int off, int size,
 			bpf_ctx_record_field_size(info, size_default);
 			return bpf_ctx_narrow_access_ok(off, size,
 							size_default);
-		case offsetof(struct bpf_sock_ops, skb_hwtstamp):
+		case bpf_ctx_range(struct bpf_sock_ops, skb_hwtstamp):
 			if (size != sizeof(__u64))
 				return false;
 			break;
@@ -9416,17 +9416,17 @@ static bool sk_msg_is_valid_access(int off, int size,
 		return false;
 
 	switch (off) {
-	case offsetof(struct sk_msg_md, data):
+	case bpf_ctx_range_ptr(struct sk_msg_md, data):
 		info->reg_type = PTR_TO_PACKET;
 		if (size != sizeof(__u64))
 			return false;
 		break;
-	case offsetof(struct sk_msg_md, data_end):
+	case bpf_ctx_range_ptr(struct sk_msg_md, data_end):
 		info->reg_type = PTR_TO_PACKET_END;
 		if (size != sizeof(__u64))
 			return false;
 		break;
-	case offsetof(struct sk_msg_md, sk):
+	case bpf_ctx_range_ptr(struct sk_msg_md, sk):
 		if (size != sizeof(__u64))
 			return false;
 		info->reg_type = PTR_TO_SOCKET;
@@ -11632,7 +11632,7 @@ static bool sk_lookup_is_valid_access(int off, int size,
 		return false;
 
 	switch (off) {
-	case offsetof(struct bpf_sk_lookup, sk):
+	case bpf_ctx_range_ptr(struct bpf_sk_lookup, sk):
 		info->reg_type = PTR_TO_SOCKET_OR_NULL;
 		return size == sizeof(__u64);
 

net/netfilter/nf_bpf_link.c

@@ -17,7 +17,7 @@ static unsigned int nf_hook_run_bpf(void *bpf_prog, struct sk_buff *skb,
 		.skb = skb,
 	};
 
-	return bpf_prog_run(prog, &ctx);
+	return bpf_prog_run_pin_on_cpu(prog, &ctx);
 }
 
 struct bpf_nf_link {

tools/testing/selftests/bpf/progs/verifier_ctx.c

@@ -218,4 +218,29 @@ __naked void null_check_8_null_bind(void)
 	: __clobber_all);
 }
 
+#define narrow_load(type, ctx, field)					\
+	SEC(type)							\
+	__description("narrow load on field " #field " of " #ctx)	\
+	__failure __msg("invalid bpf_context access")			\
+	__naked void invalid_narrow_load##ctx##field(void)		\
+	{								\
+		asm volatile ("						\
+		r1 = *(u32 *)(r1 + %[off]);				\
+		r0 = 0;							\
+		exit;"							\
+		:							\
+		: __imm_const(off, offsetof(struct ctx, field) + 4)	\
+		: __clobber_all);					\
+	}
+
+narrow_load("cgroup/getsockopt", bpf_sockopt, sk);
+narrow_load("cgroup/getsockopt", bpf_sockopt, optval);
+narrow_load("cgroup/getsockopt", bpf_sockopt, optval_end);
+narrow_load("tc", __sk_buff, sk);
+narrow_load("cgroup/bind4", bpf_sock_addr, sk);
+narrow_load("sockops", bpf_sock_ops, sk);
+narrow_load("sockops", bpf_sock_ops, skb_data);
+narrow_load("sockops", bpf_sock_ops, skb_data_end);
+narrow_load("sockops", bpf_sock_ops, skb_hwtstamp);
+
 char _license[] SEC("license") = "GPL";