staging: rtl8723bs: fix OOB read in rtw_action_frame_parse()grafted

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 <meatuni001@gmail.com>
Link: https://patch.msgid.link/20260728125456.32359-3-meatuni001@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 41 insertions, 0 deletions

diff --git a/scripts/atomic/atomics.tbl b/scripts/atomic/atomics.tbl
new file mode 100644
index 000000000..903946cbf
--- /dev/null
+++ b/scripts/atomic/atomics.tbl
@@ -0,0 +1,41 @@
+# name	meta	args...
+#
+# Where meta contains a string of variants to generate.
+# Upper-case implies _{acquire,release,relaxed} variants.
+# Valid meta values are:
+# * B/b	- bool: returns bool
+# * v	- void: returns void
+# * I/i	- int: returns base type
+# * R	- return: returns base type (has _return variants)
+# * F/f	- fetch: returns base type (has fetch_ variants)
+# * l	- load: returns base type (has _acquire order variant)
+# * s	- store: returns void (has _release order variant)
+#
+# Where args contains list of type[:name], where type is:
+# * cv	- const pointer to atomic base type (atomic_t/atomic64_t/atomic_long_t)
+# * v	- pointer to atomic base type (atomic_t/atomic64_t/atomic_long_t)
+# * i	- base type (int/s64/long)
+# * p	- pointer to base type (int/s64/long)
+#
+read			l	cv
+set			s	v	i
+add			vRF	i	v
+sub			vRF	i	v
+inc			vRF	v
+dec			vRF	v
+and			vF	i	v
+andnot			vF	i	v
+or			vF	i	v
+xor			vF	i	v
+xchg			I	v	i:new
+cmpxchg			I	v	i:old	i:new
+try_cmpxchg		B	v	p:old	i:new
+sub_and_test		b	i	v
+dec_and_test		b	v
+inc_and_test		b	v
+add_negative		B	i	v
+add_unless		fb	v	i:a	i:u
+inc_not_zero		b	v
+inc_unless_negative	b	v
+dec_unless_positive	b	v
+dec_if_positive		i	v