From ff917923f4fb9c83717ba135ee47d7e4c1567bb7 Mon Sep 17 00:00:00 2001 From: Muhammad Bilal Date: Tue, 28 Jul 2026 17:54:55 +0500 Subject: staging: rtl8723bs: fix OOB read in rtw_action_frame_parse() rtw_action_frame_parse() takes a frame_len parameter but never actually checks it before indexing into the frame body: const u8 *frame_body = frame + sizeof(struct ieee80211_hdr_3addr); ... c = frame_body[0]; ... a = frame_body[1]; frame_body already points 24 bytes (sizeof(struct ieee80211_hdr_3addr)) into frame, so reading frame_body[0] and frame_body[1] requires frame_len >= 26. A management action frame shorter than that (e.g. exactly 24 bytes, the minimum a malicious peer can send) causes a 1-2 byte out-of-bounds read. This is reachable from rtw_cfg80211_monitor_if_xmit_entry() and cfg80211_rtw_mgmt_tx() in ioctl_cfg80211.c, both of which pass attacker/user-influenced frame buffers and lengths straight through. Add the missing length check before frame_body is dereferenced. Fixes: 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal Link: https://patch.msgid.link/20260728125456.32359-3-meatuni001@gmail.com Signed-off-by: Greg Kroah-Hartman --- samples/bpf/parse_varlen.c | 150 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 150 insertions(+) create mode 100644 samples/bpf/parse_varlen.c (limited to 'samples/bpf/parse_varlen.c') diff --git a/samples/bpf/parse_varlen.c b/samples/bpf/parse_varlen.c new file mode 100644 index 000000000..d8623846e --- /dev/null +++ b/samples/bpf/parse_varlen.c @@ -0,0 +1,150 @@ +/* Copyright (c) 2016 Facebook + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + */ +#define KBUILD_MODNAME "foo" +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DEFAULT_PKTGEN_UDP_PORT 9 +#define DEBUG 0 + +static int tcp(void *data, uint64_t tp_off, void *data_end) +{ + struct tcphdr *tcp = data + tp_off; + + if (tcp + 1 > data_end) + return 0; + if (tcp->dest == htons(80) || tcp->source == htons(80)) + return TC_ACT_SHOT; + return 0; +} + +static int udp(void *data, uint64_t tp_off, void *data_end) +{ + struct udphdr *udp = data + tp_off; + + if (udp + 1 > data_end) + return 0; + if (udp->dest == htons(DEFAULT_PKTGEN_UDP_PORT) || + udp->source == htons(DEFAULT_PKTGEN_UDP_PORT)) { + if (DEBUG) { + char fmt[] = "udp port 9 indeed\n"; + + bpf_trace_printk(fmt, sizeof(fmt)); + } + return TC_ACT_SHOT; + } + return 0; +} + +static int parse_ipv4(void *data, uint64_t nh_off, void *data_end) +{ + struct iphdr *iph; + uint64_t ihl_len; + + iph = data + nh_off; + if (iph + 1 > data_end) + return 0; + + if (ip_is_fragment(iph)) + return 0; + ihl_len = iph->ihl * 4; + + if (iph->protocol == IPPROTO_IPIP) { + iph = data + nh_off + ihl_len; + if (iph + 1 > data_end) + return 0; + ihl_len += iph->ihl * 4; + } + + if (iph->protocol == IPPROTO_TCP) + return tcp(data, nh_off + ihl_len, data_end); + else if (iph->protocol == IPPROTO_UDP) + return udp(data, nh_off + ihl_len, data_end); + return 0; +} + +static int parse_ipv6(void *data, uint64_t nh_off, void *data_end) +{ + struct ipv6hdr *ip6h; + struct iphdr *iph; + uint64_t ihl_len = sizeof(struct ipv6hdr); + uint64_t nexthdr; + + ip6h = data + nh_off; + if (ip6h + 1 > data_end) + return 0; + + nexthdr = ip6h->nexthdr; + + if (nexthdr == IPPROTO_IPIP) { + iph = data + nh_off + ihl_len; + if (iph + 1 > data_end) + return 0; + ihl_len += iph->ihl * 4; + nexthdr = iph->protocol; + } else if (nexthdr == IPPROTO_IPV6) { + ip6h = data + nh_off + ihl_len; + if (ip6h + 1 > data_end) + return 0; + ihl_len += sizeof(struct ipv6hdr); + nexthdr = ip6h->nexthdr; + } + + if (nexthdr == IPPROTO_TCP) + return tcp(data, nh_off + ihl_len, data_end); + else if (nexthdr == IPPROTO_UDP) + return udp(data, nh_off + ihl_len, data_end); + return 0; +} + +SEC("varlen") +int handle_ingress(struct __sk_buff *skb) +{ + void *data = (void *)(long)skb->data; + struct ethhdr *eth = data; + void *data_end = (void *)(long)skb->data_end; + uint64_t h_proto, nh_off; + + nh_off = sizeof(*eth); + if (data + nh_off > data_end) + return 0; + + h_proto = eth->h_proto; + + if (h_proto == ETH_P_8021Q || h_proto == ETH_P_8021AD) { + struct vlan_hdr *vhdr; + + vhdr = data + nh_off; + nh_off += sizeof(struct vlan_hdr); + if (data + nh_off > data_end) + return 0; + h_proto = vhdr->h_vlan_encapsulated_proto; + } + if (h_proto == ETH_P_8021Q || h_proto == ETH_P_8021AD) { + struct vlan_hdr *vhdr; + + vhdr = data + nh_off; + nh_off += sizeof(struct vlan_hdr); + if (data + nh_off > data_end) + return 0; + h_proto = vhdr->h_vlan_encapsulated_proto; + } + if (h_proto == htons(ETH_P_IP)) + return parse_ipv4(data, nh_off, data_end); + else if (h_proto == htons(ETH_P_IPV6)) + return parse_ipv6(data, nh_off, data_end); + return 0; +} +char _license[] SEC("license") = "GPL"; -- cgit v1.3.1