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/lshrdi3.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 lib/lshrdi3.c (limited to 'lib/lshrdi3.c') diff --git a/lib/lshrdi3.c b/lib/lshrdi3.c new file mode 100644 index 000000000..312838ce2 --- /dev/null +++ b/lib/lshrdi3.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * lib/lshrdi3.c + */ + +#include +#include + +long long notrace __lshrdi3(long long u, word_type b) +{ + DWunion uu, w; + word_type bm; + + if (b == 0) + return u; + + uu.ll = u; + bm = 32 - b; + + if (bm <= 0) { + w.s.high = 0; + w.s.low = (unsigned int) uu.s.high >> -bm; + } else { + const unsigned int carries = (unsigned int) uu.s.high << bm; + + w.s.high = (unsigned int) uu.s.high >> b; + w.s.low = ((unsigned int) uu.s.low >> b) | carries; + } + + return w.ll; +} +EXPORT_SYMBOL(__lshrdi3); -- cgit v1.3.1