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, 235 insertions, 0 deletions

diff --git a/include/sound/hda_regmap.h b/include/sound/hda_regmap.h
new file mode 100644
index 000000000..e06e4847e
--- /dev/null
+++ b/include/sound/hda_regmap.h
@@ -0,0 +1,235 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * HD-audio regmap helpers
+ */
+
+#ifndef __SOUND_HDA_REGMAP_H
+#define __SOUND_HDA_REGMAP_H
+
+#include <linux/regmap.h>
+#include <sound/core.h>
+#include <sound/hdaudio.h>
+
+#define AC_AMP_FAKE_MUTE	0x10	/* fake mute bit set to amp verbs */
+
+int snd_hdac_regmap_init(struct hdac_device *codec);
+void snd_hdac_regmap_exit(struct hdac_device *codec);
+int snd_hdac_regmap_add_vendor_verb(struct hdac_device *codec,
+				    unsigned int verb);
+int snd_hdac_regmap_read_raw(struct hdac_device *codec, unsigned int reg,
+			     unsigned int *val);
+int snd_hdac_regmap_read_raw_uncached(struct hdac_device *codec,
+				      unsigned int reg, unsigned int *val);
+int snd_hdac_regmap_write_raw(struct hdac_device *codec, unsigned int reg,
+			      unsigned int val);
+int snd_hdac_regmap_update_raw(struct hdac_device *codec, unsigned int reg,
+			       unsigned int mask, unsigned int val);
+int snd_hdac_regmap_update_raw_once(struct hdac_device *codec, unsigned int reg,
+				    unsigned int mask, unsigned int val);
+void snd_hdac_regmap_sync(struct hdac_device *codec);
+
+/**
+ * snd_hdac_regmap_encode_verb - encode the verb to a pseudo register
+ * @nid: widget NID
+ * @verb: codec verb
+ *
+ * Returns an encoded pseudo register.
+ */
+#define snd_hdac_regmap_encode_verb(nid, verb)		\
+	(((verb) << 8) | 0x80000 | ((unsigned int)(nid) << 20))
+
+/**
+ * snd_hdac_regmap_encode_amp - encode the AMP verb to a pseudo register
+ * @nid: widget NID
+ * @ch: channel (left = 0, right = 1)
+ * @dir: direction (#HDA_INPUT, #HDA_OUTPUT)
+ * @idx: input index value
+ *
+ * Returns an encoded pseudo register.
+ */
+#define snd_hdac_regmap_encode_amp(nid, ch, dir, idx)			\
+	(snd_hdac_regmap_encode_verb(nid, AC_VERB_GET_AMP_GAIN_MUTE) |	\
+	 ((ch) ? AC_AMP_GET_RIGHT : AC_AMP_GET_LEFT) |			\
+	 ((dir) == HDA_OUTPUT ? AC_AMP_GET_OUTPUT : AC_AMP_GET_INPUT) | \
+	 (idx))
+
+/**
+ * snd_hdac_regmap_encode_amp_stereo - encode a pseudo register for stereo AMPs
+ * @nid: widget NID
+ * @dir: direction (#HDA_INPUT, #HDA_OUTPUT)
+ * @idx: input index value
+ *
+ * Returns an encoded pseudo register.
+ */
+#define snd_hdac_regmap_encode_amp_stereo(nid, dir, idx)		\
+	(snd_hdac_regmap_encode_verb(nid, AC_VERB_GET_AMP_GAIN_MUTE) |	\
+	 AC_AMP_SET_LEFT | AC_AMP_SET_RIGHT | /* both bits set! */	\
+	 ((dir) == HDA_OUTPUT ? AC_AMP_GET_OUTPUT : AC_AMP_GET_INPUT) | \
+	 (idx))
+
+/**
+ * snd_hdac_regmap_write - Write a verb with caching
+ * @codec: HD-audio codec base device
+ * @nid: codec NID
+ * @verb: verb to write
+ * @val: value to write
+ *
+ * For writing an amp value, use snd_hdac_regmap_update_amp().
+ *
+ * Returns: %0 if successful or a negative error code.
+ */
+static inline int
+snd_hdac_regmap_write(struct hdac_device *codec, hda_nid_t nid,
+		      unsigned int verb, unsigned int val)
+{
+	unsigned int cmd = snd_hdac_regmap_encode_verb(nid, verb);
+
+	return snd_hdac_regmap_write_raw(codec, cmd, val);
+}
+
+/**
+ * snd_hdac_regmap_update - Update a verb value with caching
+ * @codec: HD-audio codec
+ * @nid: codec NID
+ * @verb: verb to update
+ * @mask: bit mask to update
+ * @val: value to update
+ *
+ * For updating an amp value, use snd_hdac_regmap_update_amp().
+ *
+ * Returns: %0 if successful or a negative error code.
+ */
+static inline int
+snd_hdac_regmap_update(struct hdac_device *codec, hda_nid_t nid,
+		       unsigned int verb, unsigned int mask,
+		       unsigned int val)
+{
+	unsigned int cmd = snd_hdac_regmap_encode_verb(nid, verb);
+
+	return snd_hdac_regmap_update_raw(codec, cmd, mask, val);
+}
+
+/**
+ * snd_hdac_regmap_read - Read a verb with caching
+ * @codec: HD-audio codec
+ * @nid: codec NID
+ * @verb: verb to read
+ * @val: pointer to store the value
+ *
+ * For reading an amp value, use snd_hda_regmap_get_amp().
+ *
+ * Returns: %0 if successful or a negative error code.
+ */
+static inline int
+snd_hdac_regmap_read(struct hdac_device *codec, hda_nid_t nid,
+		     unsigned int verb, unsigned int *val)
+{
+	unsigned int cmd = snd_hdac_regmap_encode_verb(nid, verb);
+
+	return snd_hdac_regmap_read_raw(codec, cmd, val);
+}
+
+/**
+ * snd_hdac_regmap_get_amp - Read AMP value
+ * @codec: HD-audio codec
+ * @nid: NID to read the AMP value
+ * @ch: channel (left=0 or right=1)
+ * @dir: #HDA_INPUT or #HDA_OUTPUT
+ * @idx: the index value (only for input direction)
+ *
+ * Read AMP value.  The volume is between 0 to 0x7f, 0x80 = mute bit.
+ *
+ * Returns: the value or a negative error.
+ */
+static inline int
+snd_hdac_regmap_get_amp(struct hdac_device *codec, hda_nid_t nid,
+			int ch, int dir, int idx)
+{
+	unsigned int cmd = snd_hdac_regmap_encode_amp(nid, ch, dir, idx);
+	int err, val;
+
+	err = snd_hdac_regmap_read_raw(codec, cmd, &val);
+	return err < 0 ? err : val;
+}
+
+/**
+ * snd_hdac_regmap_update_amp - update the AMP value
+ * @codec: HD-audio codec
+ * @nid: NID to read the AMP value
+ * @ch: channel (left=0 or right=1)
+ * @dir: #HDA_INPUT or #HDA_OUTPUT
+ * @idx: the index value (only for input direction)
+ * @mask: bit mask to set
+ * @val: the bits value to set
+ *
+ * Update the AMP value with a bit mask.
+ *
+ * Returns: 0 if the value is unchanged, 1 if changed, or a negative error.
+ */
+static inline int
+snd_hdac_regmap_update_amp(struct hdac_device *codec, hda_nid_t nid,
+			   int ch, int dir, int idx, int mask, int val)
+{
+	unsigned int cmd = snd_hdac_regmap_encode_amp(nid, ch, dir, idx);
+
+	return snd_hdac_regmap_update_raw(codec, cmd, mask, val);
+}
+
+/**
+ * snd_hdac_regmap_get_amp_stereo - Read stereo AMP values
+ * @codec: HD-audio codec
+ * @nid: NID to read the AMP value
+ * @dir: #HDA_INPUT or #HDA_OUTPUT
+ * @idx: the index value (only for input direction)
+ *
+ * Read stereo AMP values.  The lower byte is left, the upper byte is right.
+ *
+ * Returns: the value or a negative error.
+ */
+static inline int
+snd_hdac_regmap_get_amp_stereo(struct hdac_device *codec, hda_nid_t nid,
+			       int dir, int idx)
+{
+	unsigned int cmd = snd_hdac_regmap_encode_amp_stereo(nid, dir, idx);
+	int err, val;
+
+	err = snd_hdac_regmap_read_raw(codec, cmd, &val);
+	return err < 0 ? err : val;
+}
+
+/**
+ * snd_hdac_regmap_update_amp_stereo - update the stereo AMP value
+ * @codec: HD-audio codec
+ * @nid: NID to read the AMP value
+ * @dir: #HDA_INPUT or #HDA_OUTPUT
+ * @idx: the index value (only for input direction)
+ * @mask: bit mask to set
+ * @val: the bits value to set
+ *
+ * Update the stereo AMP value with a bit mask.
+ * The lower byte is left, the upper byte is right.
+ *
+ * Returns: 0 if the value is unchanged, 1 if changed, or a negative error.
+ */
+static inline int
+snd_hdac_regmap_update_amp_stereo(struct hdac_device *codec, hda_nid_t nid,
+				  int dir, int idx, int mask, int val)
+{
+	unsigned int cmd = snd_hdac_regmap_encode_amp_stereo(nid, dir, idx);
+
+	return snd_hdac_regmap_update_raw(codec, cmd, mask, val);
+}
+
+/**
+ * snd_hdac_regmap_sync_node - sync the widget node attributes
+ * @codec: HD-audio codec
+ * @nid: NID to sync
+ */
+static inline void
+snd_hdac_regmap_sync_node(struct hdac_device *codec, hda_nid_t nid)
+{
+	regcache_mark_dirty(codec->regmap);
+	regcache_sync_region(codec->regmap, nid << 20, ((nid + 1) << 20) - 1);
+}
+
+#endif /* __SOUND_HDA_REGMAP_H */