rtw_cfg80211_monitor_if_xmit_entry() removes the radiotap header and
then reads the 802.11 frame control field without checking that a base
802.11 header remains.

The data path also pulls the calculated 802.11, QoS and SNAP header
span before confirming that the skb contains it. A truncated frame can
therefore cause out-of-bounds reads or leave insufficient data for the
Ethernet address writes.

Reject frames that do not contain the base 802.11 header and data
frames that do not contain their complete calculated header span.

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Mariano Baragiola <mbaragiola@linux.com>
Link: https://patch.msgid.link/20260727160859.1917096-1-mbaragiola@linux.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The WEP shared-key authentication handler uses the challenge-text
element's attacker-controlled length without checking it against the
fixed 128-byte chg_txt buffer.

In OnAuthClient() the length from rtw_get_ie() - up to 255 - is used
to perform memcpy() into the 128-byte pmlmeinfo->chg_txt, so a
malicious AP sending a malformed WLAN_EID_CHALLENGE element can
overflow/underfill chg_txt by up to 127 bytes. It is reachable over the
air, before association, during shared-key authentication. In the case
of an overflow, the driver can write out of bounds. In the case of an
underfill, the driver can echo stale buffer memory.

The challenge text is defined to be exactly 128 octets, which is
already provided as the WLAN_AUTH_CHALLENGE_LEN define; require the
element to be exactly that length before use.

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Panagiotis Petrakopoulos <npetrakopoulos2003@gmail.com>
Link: https://patch.msgid.link/20260720082409.168379-1-npetrakopoulos2003@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

WMM_param_handler() copies a fixed-size WMM parameter element out of a
received information element without checking that the element is long
enough, causing an out-of-bounds read for a short WMM IE.

The handler reads sizeof(struct WMM_para_element) (18) bytes at
pIE->data + 6, so it requires pIE->length to be at least 24
(WLAN_WMM_LEN), but it never validates the length. Two of its three
callers reach it after matching only the WMM OUI: OnAssocRsp() in
rtw_mlme_ext.c matches a 6-byte OUI, and join_cmd_hdl() matches a
4-byte OUI, before calling the handler. A vendor-specific IE carrying
the WMM OUI but a length between 6 and 23, placed in an association
response or in the IE blob handed to join_cmd_hdl(), passes the OUI
check and then makes the memcmp() and memcpy() at pIE->data + 6 read
past the end of the element. OnAssocRsp() parses a frame received from
the AP, so this is reachable from a remote peer.

The remaining caller in rtw_wlan_util.c already guards the handler with
"pIE->length == WLAN_WMM_LEN". Move the equivalent check into the
handler itself so every caller is covered; the sibling IE handlers in
the same parsing loop (HT_caps_handler(), HT_info_handler(),
ERP_IE_handler()) likewise bound their accesses by pIE->length.

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
Link: https://patch.msgid.link/20260719041509.97894-1-meatuni001@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

rtw_get_wpa_ie() reads bytes at fixed offsets into a vendor-specific
information element without checking that the element is long enough,
causing an out-of-bounds read for a short trailing IE.

The function locates a vendor-specific IE (EID 221) with rtw_get_ie()
and then compares a 4-byte OUI+type at pbuf + 2 and reads a 2-byte
version word at pbuf + 6. Those accesses require the IE body to be at
least 6 bytes, but rtw_get_ie() only guarantees that the element fits
within the buffer; it does not enforce a minimum body length. A
vendor-specific IE whose length byte is 0 to 5, placed at the end of
the buffer, therefore makes these reads run past the end of the IE and
past the end of the buffer itself.

The buffer holds information elements taken from received management
frames and from the IE blob passed to rtw_cfg80211_set_wpa_ie(), which
is kmemdup'd to its exact length, so the read can run off the end of
the allocation.

The sibling helpers rtw_get_sec_ie(), rtw_get_wapi_ie() and
rtw_get_wps_ie() in this file already reject too-short vendor-specific
IEs before their OUI memcmp(); rtw_get_wpa_ie() was never brought in
line with them, and needs a minimum of 6 rather than 4 bytes because
of the version word. Add the missing length check.

Fixes: 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
Link: https://patch.msgid.link/20260719030631.88254-1-meatuni001@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

rtw_get_wps_ie() iterates over IE data from network frames without
validating that the IE header and payload fit within the remaining
buffer before reading them. Specifically:

- in_ie[cnt + 1] is read without checking cnt + 1 < in_len
- memcmp(&in_ie[cnt + 2], ...) accesses cnt + 2 without bounds check
- in_ie[cnt + 1] is used as length without verifying payload fits

Add bounds checks at the top of the loop body to break early if fewer
than 2 bytes remain for the IE header, or if the declared payload
extends past the end of the buffer. Also require at least 4 bytes of
payload before comparing the WPS OUI.

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Moksh Panicker <mokshpanicker.7@gmail.com>
Link: https://patch.msgid.link/20260625202911.26782-1-mokshpanicker.7@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

rtw_get_chan_type() maps the driver's channel offset to nl80211 channel
types the wrong way around.

In this driver HAL_PRIME_CHNL_OFFSET_LOWER means the primary channel is
the lower 20 MHz half of the 40 MHz pair, i.e. the secondary channel is
above the primary one: rtw_get_center_ch() computes the center channel
as "channel + 2" for OFFSET_LOWER, and bwmode_update_check() sets
OFFSET_LOWER when the AP's HT operation IE announces SCA (secondary
channel above). In nl80211 terms that is NL80211_CHAN_HT40PLUS, not
HT40MINUS.

Because of the inversion, cfg80211_rtw_get_channel() reports an HT40+
association as HT40-. For an HT40+ AP on a low channel (e.g. channel 3)
the resulting chandef spans below the 2.4 GHz band edge and is invalid,
so the regulatory core tears the connection down 60 seconds
(REG_ENFORCE_GRACE_MS) after the AP's country IE triggers a regdomain
change: reg_check_chans_work() considers the reported chandef unusable
and calls cfg80211_leave(). The supplicant then reconnects, the country
IE changes the regdomain again, and the cycle repeats, causing a
disconnect/reconnect loop every ~65 seconds for as long as the link is
up.

Observed on a TECLAST X80 Power tablet (RTL8723BS) associated to an
HT40+ AP on channel 3 with a KR country IE; a kprobe trace showed
cfg80211_disconnect() being invoked from reg_check_chans_work(). With
the mapping fixed, "iw dev wlan0 info" reports the correct
"width: 40 MHz, center1: 2432 MHz" and the periodic disconnects stop.

Fixes: 5402cc178c5d ("staging: rtl8723bs: add get_channel cfg80211 implementation")
Cc: stable@vger.kernel.org
Assisted-by: Claude-Code:claude-fable-5 bpftrace
Signed-off-by: MinJea Kim <qndkdrnl@gmail.com>
Link: https://patch.msgid.link/20260714131421.3980-1-qndkdrnl@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Three IE/attribute parsing functions have missing bounds checks.

rtw_get_sec_ie() and rtw_get_wapi_ie() iterate over a raw IE buffer
without verifying that the header bytes (tag + length) are within the
remaining buffer before reading them.  Additionally, rtw_get_sec_ie()
compares the 4-byte WPA OUI at cnt+2 without checking that at least
6 bytes remain, and rtw_get_wapi_ie() compares a 4-byte WAPI OUI at
cnt+6 without checking that at least 10 bytes remain.

rtw_get_wps_attr() reads wps_ie[0] and wps_ie+2 unconditionally at
entry, before verifying that wps_ielen is large enough to contain
the 6-byte WPS IE header (element_id + length + 4-byte OUI).  Inside
the attribute loop, get_unaligned_be16() is called on attr_ptr and
attr_ptr+2 without checking that 4 bytes remain in the buffer.

Add a cnt+2 bounds check before each loop body in rtw_get_sec_ie()
and rtw_get_wapi_ie(), guard each multi-byte comparison with a minimum
IE length requirement, add a wps_ielen < 6 early return in
rtw_get_wps_attr(), and add a 4-byte bounds check in its inner loop.

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
Link: https://patch.msgid.link/20260522004531.1038924-8-hossu.alexandru@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The loop in is_ap_in_tkip() iterates over IEs without verifying that
enough bytes remain before dereferencing the IE header or its payload:

- pIE->element_id and pIE->length are read without checking that
  i + sizeof(*pIE) <= ie_length, so a truncated IE at the end of the
  buffer causes an OOB read.

- For WLAN_EID_VENDOR_SPECIFIC the code compares pIE->data + 12,
  which requires pIE->length >= 16.  For WLAN_EID_RSN it compares
  pIE->data + 8, requiring pIE->length >= 12.  Neither requirement
  is checked.

Add the missing IE header and payload bounds checks and guard each
data access with an explicit pIE->length minimum, matching the
pattern established in update_beacon_info().

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
Link: https://patch.msgid.link/20260522004531.1038924-7-hossu.alexandru@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The IE parsing loop in OnAssocRsp() advances by (pIE->length + 2) each
iteration but only guards on i < pkt_len. When a malicious AP sends an
AssocResponse whose last IE has only one byte remaining in the frame
(the element_id byte lands at pkt_len-1), the loop reads pIE->length
from pframe[pkt_len], which is one byte past the allocated receive buffer.

Additionally, even when the header bytes are in bounds, pIE->length
itself can extend the data window beyond pkt_len, silently passing a
truncated IE to the handler functions.

Add two guards at the top of the loop body:
  1. Break if fewer than sizeof(*pIE) bytes remain (can't read header).
  2. Break if the IE's declared data extends past pkt_len.

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
Reviewed-by: Luka Gejak <luka.gejak@linux.dev>
Link: https://patch.msgid.link/20260522004531.1038924-6-hossu.alexandru@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

HT_caps_handler() iterates pIE->length bytes and writes into
HT_caps.u.HT_cap[], which is a fixed 26-byte array (sizeof struct
HT_caps_element). Because pIE->length is a raw u8 from an over-the-air
802.11 AssocResponse frame and is never validated, a malicious AP can
set it up to 255, causing up to 229 bytes of out-of-bounds writes into
adjacent fields of struct mlme_ext_info.

Truncate the iteration count to the size of HT_caps.u.HT_cap using
umin() so that data from a longer-than-expected IE is silently ignored
rather than written out of bounds, preserving interoperability with APs
that pad the element. An early return on oversized IEs was considered
but rejected: it would bypass the pmlmeinfo->HT_caps_enable = 1
assignment that precedes the loop, silently disabling HT mode for APs
that append extra bytes to the HT Capabilities IE.

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
Reviewed-by: Luka Gejak <luka.gejak@linux.dev>
Link: https://patch.msgid.link/20260522004531.1038924-5-hossu.alexandru@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>