linux.git/net/wireless, branch master Linux kernel source tree wifi: cfg80211: bound element ID read when checking non-inheritance 2026-07-07T12:00:35+00:00 HE WEI (ギカク) skyexpoc@gmail.com 2026-07-07T09:48:28+00:00 cb8afea4655ff004fa7feee825d5c79783525383 cfg80211_is_element_inherited() reads the first data octet of the candidate element (id = elem->data[0]) to look it up in an extension non-inheritance list. It does so after testing elem->id, but without verifying that the element actually has a data octet. A zero-length extension element (WLAN_EID_EXTENSION with length 0) therefore makes it read one octet past the end of the element. _ieee802_11_parse_elems_full() runs this check for every element of a frame once a non-inheritance context exists -- e.g. while parsing a per-STA profile of a Multi-Link element in a (re)association response, or a non-transmitted BSS profile -- so a crafted frame from an AP can trigger a one-octet slab-out-of-bounds read during element parsing: BUG: KASAN: slab-out-of-bounds in cfg80211_is_element_inherited Read of size 1 ... in net/wireless/scan.c Return early (treat the element as inherited) when an extension element carries no data, mirroring the existing handling of empty ID lists. The bug was found by fuzzing ieee802_11_parse_elems_full() under KASAN. Fixes: f7dacfb11475 ("cfg80211: support non-inheritance element") Signed-off-by: HE WEI (ギカク) <skyexpoc@gmail.com> Link: https://patch.msgid.link/20260707094828.16465-1-skyexpoc@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
cfg80211_is_element_inherited() reads the first data octet of the
candidate element (id = elem->data[0]) to look it up in an extension
non-inheritance list. It does so after testing elem->id, but without
verifying that the element actually has a data octet. A zero-length
extension element (WLAN_EID_EXTENSION with length 0) therefore makes it
read one octet past the end of the element.

_ieee802_11_parse_elems_full() runs this check for every element of a
frame once a non-inheritance context exists -- e.g. while parsing a
per-STA profile of a Multi-Link element in a (re)association response,
or a non-transmitted BSS profile -- so a crafted frame from an AP can
trigger a one-octet slab-out-of-bounds read during element parsing:

  BUG: KASAN: slab-out-of-bounds in cfg80211_is_element_inherited
  Read of size 1 ... in net/wireless/scan.c

Return early (treat the element as inherited) when an extension element
carries no data, mirroring the existing handling of empty ID lists.

The bug was found by fuzzing ieee802_11_parse_elems_full() under KASAN.

Fixes: f7dacfb11475 ("cfg80211: support non-inheritance element")
Signed-off-by: HE WEI (ギカク) <skyexpoc@gmail.com>
Link: https://patch.msgid.link/20260707094828.16465-1-skyexpoc@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
wifi: cfg80211: validate assoc response length before status and IE access 2026-07-07T07:31:38+00:00 Zhao Li enderaoelyther@gmail.com 2026-07-07T02:53:35+00:00 b760113aeca2e9362d56bf9e9263373ffe6c8eb3 cfg80211_rx_assoc_resp() initialises the status and response-IE fields of cfg80211_connect_resp_params from the management frame before proving that the frame is long enough for those offsets. S1G and regular association responses also have different IE offsets, but the S1G path only patched resp_ie after the unsafe initialiser had already run. Defer resp_ie, resp_ie_len, and status to after the link-iteration loop. Use a bool to remember whether the frame is S1G, then validate the appropriate minimum length and set all three fields in a single if/else block. Funnel short-frame and SME-reject cleanup through a shared free_bss label for the abandon paths. Assisted-by: Codex:gpt-5.5 Assisted-by: Claude:claude-opus-4.8 Signed-off-by: Zhao Li <enderaoelyther@gmail.com> Link: https://patch.msgid.link/20260707025336.22557-2-enderaoelyther@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
cfg80211_rx_assoc_resp() initialises the status and response-IE fields
of cfg80211_connect_resp_params from the management frame before
proving that the frame is long enough for those offsets. S1G and
regular association responses also have different IE offsets, but the
S1G path only patched resp_ie after the unsafe initialiser had already
run.

Defer resp_ie, resp_ie_len, and status to after the link-iteration
loop. Use a bool to remember whether the frame is S1G, then validate
the appropriate minimum length and set all three fields in a single
if/else block. Funnel short-frame and SME-reject cleanup through a
shared free_bss label for the abandon paths.

Assisted-by: Codex:gpt-5.5
Assisted-by: Claude:claude-opus-4.8
Signed-off-by: Zhao Li <enderaoelyther@gmail.com>
Link: https://patch.msgid.link/20260707025336.22557-2-enderaoelyther@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
wifi: cfg80211: validate rx/tx MLME callback frame lengths before access 2026-07-07T07:29:26+00:00 Zhao Li enderaoelyther@gmail.com 2026-07-07T02:53:34+00:00 d5e4586546974179feca305a94e07fac3e9727fe cfg80211_rx_mlme_mgmt() and cfg80211_tx_mlme_mgmt() call tracepoints before rejecting frames shorter than the frame-control field. After that, they only require len >= 2 before dispatching into subtype handlers that assume their fixed fields are present. The frames that trip this are not shorter than 2 bytes; they are short relative to their subtype. mwifiex is a concrete in-tree example on the length side: mwifiex_process_mgmt_packet() only requires a 4-address ieee80211_hdr plus the 2-byte firmware length prefix before handing the frame to cfg80211_rx_mlme_mgmt(). After stripping the length prefix and removing addr4, pkt_len can be exactly 24: a bare 3-address management header with no reason-code body. The existing WARN_ON(len < 2) does not fire on such a frame, and cfg80211_process_deauth() then reads u.deauth.reason_code as a two-byte access starting at offset 24, immediately past the 24-byte buffer. Add a frame-control length gate, then validate each subtype's minimum frame size in an if/else-if chain that mirrors the dispatch logic. Trace only after the frame is known to be well-formed. Side effects of this change: - The WARN_ON(len < 2) is dropped. It only guarded the frame_control read, never the subtype fixed fields, and it does not fire on the frames that actually trigger the out-of-bounds read (which are >= 2). The len >= 2 check is kept as the guard before dereferencing frame_control, but without the warning: these are exported callbacks and a malformed frame from a driver should be dropped silently rather than backtraced. - cfg80211_tx_mlme_mgmt() previously routed every non-deauth subtype through disassociation handling; it now silently ignores unrecognised subtypes. Assisted-by: Codex:gpt-5.5 Assisted-by: Claude:claude-opus-4.8 Signed-off-by: Zhao Li <enderaoelyther@gmail.com> Link: https://patch.msgid.link/20260707025336.22557-1-enderaoelyther@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
cfg80211_rx_mlme_mgmt() and cfg80211_tx_mlme_mgmt() call tracepoints
before rejecting frames shorter than the frame-control field. After
that, they only require len >= 2 before dispatching into subtype
handlers that assume their fixed fields are present.

The frames that trip this are not shorter than 2 bytes; they are short
relative to their subtype. mwifiex is a concrete in-tree example on the
length side: mwifiex_process_mgmt_packet() only requires a 4-address
ieee80211_hdr plus the 2-byte firmware length prefix before handing the
frame to cfg80211_rx_mlme_mgmt(). After stripping the length prefix and
removing addr4, pkt_len can be exactly 24: a bare 3-address management
header with no reason-code body. The existing WARN_ON(len < 2) does not
fire on such a frame, and cfg80211_process_deauth() then reads
u.deauth.reason_code as a two-byte access starting at offset 24,
immediately past the 24-byte buffer.

Add a frame-control length gate, then validate each subtype's minimum
frame size in an if/else-if chain that mirrors the dispatch logic. Trace
only after the frame is known to be well-formed.

Side effects of this change:
 - The WARN_ON(len < 2) is dropped. It only guarded the frame_control
   read, never the subtype fixed fields, and it does not fire on the
   frames that actually trigger the out-of-bounds read (which are >= 2).
   The len >= 2 check is kept as the guard before dereferencing
   frame_control, but without the warning: these are exported callbacks
   and a malformed frame from a driver should be dropped silently rather
   than backtraced.
 - cfg80211_tx_mlme_mgmt() previously routed every non-deauth subtype
   through disassociation handling; it now silently ignores unrecognised
   subtypes.

Assisted-by: Codex:gpt-5.5
Assisted-by: Claude:claude-opus-4.8
Signed-off-by: Zhao Li <enderaoelyther@gmail.com>
Link: https://patch.msgid.link/20260707025336.22557-1-enderaoelyther@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
wifi: cfg80211: use wiphy work for socket owner autodisconnect 2026-07-07T07:27:42+00:00 Cen Zhang zzzccc427@gmail.com 2026-07-06T15:24:18+00:00 0c2ed186bbe14304415476d6707b747dddcd8583 nl80211_netlink_notify() walks the cfg80211 wireless device list when a NETLINK_GENERIC socket is released. If the socket owns a connection, the notifier queues the embedded wdev->disconnect_wk work item. That work is a plain work_struct today. NETDEV_GOING_DOWN cancels it, but a NETLINK_URELEASE notifier that already observed conn_owner_nlportid can queue it after that cancel returns. _cfg80211_unregister_wdev() then removes the wdev from the list and waits for RCU readers, but synchronize_net() does not drain work queued by such a reader. Make the autodisconnect work a wiphy_work instead. The callback already needs the wiphy mutex, and wiphy_work runs under that mutex. This lets teardown cancel pending autodisconnect work while holding the mutex, without a cancel_work_sync() vs. worker locking concern. Also cancel the wiphy work after list_del_rcu() and synchronize_net(). Any NETLINK_URELEASE notifier that had already reached the wdev list has then either queued the work and it is removed, or can no longer find the wdev. Fixes: bd2522b16884 ("cfg80211: NL80211_ATTR_SOCKET_OWNER support for CMD_CONNECT") Suggested-by: Johannes Berg <johannes@sipsolutions.net> Assisted-by: Codex:gpt-5.5 Signed-off-by: Cen Zhang <zzzccc427@gmail.com> Link: https://patch.msgid.link/20260706152418.779226-1-zzzccc427@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
nl80211_netlink_notify() walks the cfg80211 wireless device list when a
NETLINK_GENERIC socket is released. If the socket owns a connection, the
notifier queues the embedded wdev->disconnect_wk work item.

That work is a plain work_struct today. NETDEV_GOING_DOWN cancels it, but a
NETLINK_URELEASE notifier that already observed conn_owner_nlportid can
queue it after that cancel returns. _cfg80211_unregister_wdev() then
removes the wdev from the list and waits for RCU readers, but
synchronize_net() does not drain work queued by such a reader.

Make the autodisconnect work a wiphy_work instead. The callback already
needs the wiphy mutex, and wiphy_work runs under that mutex. This lets
teardown cancel pending autodisconnect work while holding the mutex,
without a cancel_work_sync() vs. worker locking concern.

Also cancel the wiphy work after list_del_rcu() and synchronize_net(). Any
NETLINK_URELEASE notifier that had already reached the wdev list has then
either queued the work and it is removed, or can no longer find the wdev.

Fixes: bd2522b16884 ("cfg80211: NL80211_ATTR_SOCKET_OWNER support for CMD_CONNECT")
Suggested-by: Johannes Berg <johannes@sipsolutions.net>
Assisted-by: Codex:gpt-5.5
Signed-off-by: Cen Zhang <zzzccc427@gmail.com>
Link: https://patch.msgid.link/20260706152418.779226-1-zzzccc427@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
wifi: cfg80211: reject empty PMSR peer lists 2026-07-06T12:11:10+00:00 Zhao Li enderaoelyther@gmail.com 2026-06-12T13:37:18+00:00 57c05ce14fea03df01288fe1250f49197e161710 A PMSR request with an empty peers array is not a useful request and weakens the cfg80211-to-driver contract by allowing start_pmsr() with no target peer. Reject empty peer lists before allocating the request object or calling into the driver. Fixes: 9bb7e0f24e7e7 ("cfg80211: add peer measurement with FTM initiator API") Assisted-by: Codex:gpt-5.5 Assisted-by: Claude:claude-opus-4.8 Signed-off-by: Zhao Li <enderaoelyther@gmail.com> Link: https://patch.msgid.link/20260612133717.93783-2-enderaoelyther@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
A PMSR request with an empty peers array is not a useful request and
weakens the cfg80211-to-driver contract by allowing start_pmsr() with
no target peer.

Reject empty peer lists before allocating the request object or calling
into the driver.

Fixes: 9bb7e0f24e7e7 ("cfg80211: add peer measurement with FTM initiator API")
Assisted-by: Codex:gpt-5.5
Assisted-by: Claude:claude-opus-4.8
Signed-off-by: Zhao Li <enderaoelyther@gmail.com>
Link: https://patch.msgid.link/20260612133717.93783-2-enderaoelyther@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
wifi: cfg80211: reject unsupported PMSR FTM location requests 2026-07-06T12:11:10+00:00 Zhao Li enderaoelyther@gmail.com 2026-06-12T13:37:11+00:00 69ef6a7ec277f16d216be8da2b3cbe872786c999 PMSR FTM location request flags are syntactically valid, but they must be rejected when the device capability does not advertise support for them. Return an error immediately after rejecting unsupported LCI or civic location request bits so the request cannot reach the driver. Fixes: 9bb7e0f24e7e7 ("cfg80211: add peer measurement with FTM initiator API") Assisted-by: Codex:gpt-5.5 Assisted-by: Claude:claude-opus-4.8 Signed-off-by: Zhao Li <enderaoelyther@gmail.com> Link: https://patch.msgid.link/20260612133710.93544-2-enderaoelyther@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
PMSR FTM location request flags are syntactically valid, but they must
be rejected when the device capability does not advertise support for
them.

Return an error immediately after rejecting unsupported LCI or civic
location request bits so the request cannot reach the driver.

Fixes: 9bb7e0f24e7e7 ("cfg80211: add peer measurement with FTM initiator API")
Assisted-by: Codex:gpt-5.5
Assisted-by: Claude:claude-opus-4.8
Signed-off-by: Zhao Li <enderaoelyther@gmail.com>
Link: https://patch.msgid.link/20260612133710.93544-2-enderaoelyther@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
wifi: cfg80211: validate PMSR FTM preamble range 2026-07-06T12:11:10+00:00 Zhao Li enderaoelyther@gmail.com 2026-06-12T13:37:04+00:00 36230936468f0ba4930e94aef496fc229d4bb951 PMSR FTM request parsing accepts preamble values outside the enumerated nl80211 preamble range. Reject out-of-range values before using them in the parser capability bit test using the policy. Fixes: 9bb7e0f24e7e7 ("cfg80211: add peer measurement with FTM initiator API") Assisted-by: Codex:gpt-5.5 Assisted-by: Claude:claude-opus-4.8 Signed-off-by: Zhao Li <enderaoelyther@gmail.com> Link: https://patch.msgid.link/20260612133703.93274-2-enderaoelyther@gmail.com [drop unnecessary check] Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
PMSR FTM request parsing accepts preamble values outside the
enumerated nl80211 preamble range.

Reject out-of-range values before using them in the parser capability
bit test using the policy.

Fixes: 9bb7e0f24e7e7 ("cfg80211: add peer measurement with FTM initiator API")
Assisted-by: Codex:gpt-5.5
Assisted-by: Claude:claude-opus-4.8
Signed-off-by: Zhao Li <enderaoelyther@gmail.com>
Link: https://patch.msgid.link/20260612133703.93274-2-enderaoelyther@gmail.com
[drop unnecessary check]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
wifi: cfg80211: validate PMSR measurement type data 2026-07-06T12:11:10+00:00 Zhao Li enderaoelyther@gmail.com 2026-06-12T13:36:57+00:00 41aa973eb05922848dded26875c55ef982ac1c49 PMSR request parsing accepts missing or duplicated measurement type entries in NL80211_PMSR_REQ_ATTR_DATA. Track whether one measurement type was already provided, reject a second one immediately, and return an error if the request data block contains no measurement type at all. Fixes: 9bb7e0f24e7e7 ("cfg80211: add peer measurement with FTM initiator API") Assisted-by: Codex:gpt-5.5 Assisted-by: Claude:claude-opus-4.8 Signed-off-by: Zhao Li <enderaoelyther@gmail.com> Link: https://patch.msgid.link/20260612133656.92900-2-enderaoelyther@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
PMSR request parsing accepts missing or duplicated measurement type
entries in NL80211_PMSR_REQ_ATTR_DATA.

Track whether one measurement type was already provided, reject a
second one immediately, and return an error if the request data block
contains no measurement type at all.

Fixes: 9bb7e0f24e7e7 ("cfg80211: add peer measurement with FTM initiator API")
Assisted-by: Codex:gpt-5.5
Assisted-by: Claude:claude-opus-4.8
Signed-off-by: Zhao Li <enderaoelyther@gmail.com>
Link: https://patch.msgid.link/20260612133656.92900-2-enderaoelyther@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
wifi: nl80211: constrain MBSSID TX link ID range 2026-07-06T12:11:10+00:00 Zhao Li enderaoelyther@gmail.com 2026-06-12T13:18:56+00:00 172f06023669f0a96d32511669ff45c600731380 MBSSID transmitted-profile link IDs are valid only in the range 0..IEEE80211_MLD_MAX_NUM_LINKS - 1. Constrain the nl80211 policy to reject out-of-range values during attribute validation. Fixes: 37523c3c47b3 ("wifi: nl80211: add link id of transmitted profile for MLO MBSSID") Assisted-by: Codex:gpt-5.5 Assisted-by: Claude:claude-opus-4.8 Signed-off-by: Zhao Li <enderaoelyther@gmail.com> Link: https://patch.msgid.link/20260612131854.43575-4-enderaoelyther@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
MBSSID transmitted-profile link IDs are valid only in the range
0..IEEE80211_MLD_MAX_NUM_LINKS - 1. Constrain the nl80211 policy to
reject out-of-range values during attribute validation.

Fixes: 37523c3c47b3 ("wifi: nl80211: add link id of transmitted profile for MLO MBSSID")
Assisted-by: Codex:gpt-5.5
Assisted-by: Claude:claude-opus-4.8
Signed-off-by: Zhao Li <enderaoelyther@gmail.com>
Link: https://patch.msgid.link/20260612131854.43575-4-enderaoelyther@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
wifi: nl80211: validate nested MBSSID IE blobs 2026-07-06T12:11:09+00:00 Zhao Li enderaoelyther@gmail.com 2026-06-12T13:18:55+00:00 7f4b01812323443b55e4c65381c9dc851ff009e3 Validate each nested NL80211_ATTR_MBSSID_ELEMS entry as a well-formed information-element stream before storing it for beacon construction. RNR parsing already validates each nested blob with validate_ie_attr() before storing it. Apply the same syntactic IE validation to MBSSID entries before counting and copying their data and length pointers. Fixes: dc1e3cb8da8b ("nl80211: MBSSID and EMA support in AP mode") Assisted-by: Codex:gpt-5.5 Assisted-by: Claude:claude-opus-4.8 Signed-off-by: Zhao Li <enderaoelyther@gmail.com> Link: https://patch.msgid.link/20260612131854.43575-3-enderaoelyther@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
Validate each nested NL80211_ATTR_MBSSID_ELEMS entry as a well-formed
information-element stream before storing it for beacon construction.

RNR parsing already validates each nested blob with validate_ie_attr()
before storing it. Apply the same syntactic IE validation to MBSSID
entries before counting and copying their data and length pointers.

Fixes: dc1e3cb8da8b ("nl80211: MBSSID and EMA support in AP mode")
Assisted-by: Codex:gpt-5.5
Assisted-by: Claude:claude-opus-4.8
Signed-off-by: Zhao Li <enderaoelyther@gmail.com>
Link: https://patch.msgid.link/20260612131854.43575-3-enderaoelyther@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>