diff options
| author | Sun Jian <sun.jian.kdev@gmail.com> | 2026-04-08 11:46:22 +0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-04-12 15:42:57 -0700 |
| commit | 12bec2bd4b76d81c5d3996bd14ec1b7f4d983747 (patch) | |
| tree | 80a727efb00482cf7eb93fea0192f72a86d296d9 /net | |
| parent | 47687a29b2c3acc9aa553737d482645813878aed (diff) | |
bpf: reject short IPv4/IPv6 inputs in bpf_prog_test_run_skb
bpf_prog_test_run_skb() calls eth_type_trans() first and then uses
skb->protocol to initialize sk family and address fields for the test
run.
For IPv4 and IPv6 packets, it may access ip_hdr(skb) or ipv6_hdr(skb)
even when the provided test input only contains an Ethernet header.
Reject the input earlier if the Ethernet frame carries IPv4/IPv6
EtherType but the L3 header is too short.
Fold the IPv4/IPv6 header length checks into the existing protocol
switch and return -EINVAL before accessing the network headers.
Fixes: fa5cb548ced6 ("bpf: Setup socket family and addresses in bpf_prog_test_run_skb")
Reported-by: syzbot+619b9ef527f510a57cfc@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=619b9ef527f510a57cfc
Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com>
Link: https://lore.kernel.org/r/20260408034623.180320-2-sun.jian.kdev@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/bpf/test_run.c | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 4cd6b3ea1815..2bc04feadfab 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -1137,19 +1137,23 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, switch (skb->protocol) { case htons(ETH_P_IP): - sk->sk_family = AF_INET; - if (sizeof(struct iphdr) <= skb_headlen(skb)) { - sk->sk_rcv_saddr = ip_hdr(skb)->saddr; - sk->sk_daddr = ip_hdr(skb)->daddr; + if (skb_headlen(skb) < sizeof(struct iphdr)) { + ret = -EINVAL; + goto out; } + sk->sk_family = AF_INET; + sk->sk_rcv_saddr = ip_hdr(skb)->saddr; + sk->sk_daddr = ip_hdr(skb)->daddr; break; #if IS_ENABLED(CONFIG_IPV6) case htons(ETH_P_IPV6): - sk->sk_family = AF_INET6; - if (sizeof(struct ipv6hdr) <= skb_headlen(skb)) { - sk->sk_v6_rcv_saddr = ipv6_hdr(skb)->saddr; - sk->sk_v6_daddr = ipv6_hdr(skb)->daddr; + if (skb_headlen(skb) < sizeof(struct ipv6hdr)) { + ret = -EINVAL; + goto out; } + sk->sk_family = AF_INET6; + sk->sk_v6_rcv_saddr = ipv6_hdr(skb)->saddr; + sk->sk_v6_daddr = ipv6_hdr(skb)->daddr; break; #endif default: |