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 --- lib/muldi3.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 lib/muldi3.c (limited to 'lib/muldi3.c') diff --git a/lib/muldi3.c b/lib/muldi3.c new file mode 100644 index 000000000..9150ac130 --- /dev/null +++ b/lib/muldi3.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + */ + +#include +#include + +#define W_TYPE_SIZE 32 + +#define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2)) +#define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1)) +#define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2)) + +/* If we still don't have umul_ppmm, define it using plain C. */ +#if !defined(umul_ppmm) +#define umul_ppmm(w1, w0, u, v) \ + do { \ + unsigned long __x0, __x1, __x2, __x3; \ + unsigned short __ul, __vl, __uh, __vh; \ + \ + __ul = __ll_lowpart(u); \ + __uh = __ll_highpart(u); \ + __vl = __ll_lowpart(v); \ + __vh = __ll_highpart(v); \ + \ + __x0 = (unsigned long) __ul * __vl; \ + __x1 = (unsigned long) __ul * __vh; \ + __x2 = (unsigned long) __uh * __vl; \ + __x3 = (unsigned long) __uh * __vh; \ + \ + __x1 += __ll_highpart(__x0); /* this can't give carry */\ + __x1 += __x2; /* but this indeed can */ \ + if (__x1 < __x2) /* did we get it? */ \ + __x3 += __ll_B; /* yes, add it in the proper pos */ \ + \ + (w1) = __x3 + __ll_highpart(__x1); \ + (w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\ + } while (0) +#endif + +#if !defined(__umulsidi3) +#define __umulsidi3(u, v) ({ \ + DWunion __w; \ + umul_ppmm(__w.s.high, __w.s.low, u, v); \ + __w.ll; \ + }) +#endif + +long long notrace __muldi3(long long u, long long v) +{ + const DWunion uu = {.ll = u}; + const DWunion vv = {.ll = v}; + DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)}; + + w.s.high += ((unsigned long) uu.s.low * (unsigned long) vv.s.high + + (unsigned long) uu.s.high * (unsigned long) vv.s.low); + + return w.ll; +} +EXPORT_SYMBOL(__muldi3); -- cgit v1.3.1