linux-stable.git/net/wireless, branch v6.6.148 Linux kernel stable tree wifi: cfg80211: bound element ID read when checking non-inheritance 2026-08-03T09:15:14+00:00 HE WEI (ギカク) skyexpoc@gmail.com 2026-07-07T09:48:28+00:00 20c308d9a57722801961f816395bf825f7bde6bc [ Upstream commit 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> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: reject unsupported PMSR FTM location requests 2026-08-03T09:15:14+00:00 Zhao Li enderaoelyther@gmail.com 2026-06-12T13:37:11+00:00 a17f5d27cca22dc4b14a7216657ea1c17d8e134c [ Upstream commit 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> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: validate PMSR FTM preamble range 2026-08-03T09:15:13+00:00 Zhao Li enderaoelyther@gmail.com 2026-06-12T13:37:04+00:00 44ea65d779e2d23b2264fea6af2d0c666a3ec9fb [ Upstream commit 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> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: validate PMSR measurement type data 2026-08-03T09:15:13+00:00 Zhao Li enderaoelyther@gmail.com 2026-06-12T13:36:57+00:00 642d8373c4c58296644de660532cd381aaea81c7 [ Upstream commit 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> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: nl80211: validate nested MBSSID IE blobs 2026-08-03T09:15:13+00:00 Zhao Li enderaoelyther@gmail.com 2026-06-12T13:18:55+00:00 2d372cb06387bd2bb6b9bc9e90d8263ef6ebdea4 [ Upstream commit 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> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: nl80211: free RNR data on MBSSID mismatch 2026-08-03T09:15:13+00:00 Zhao Li enderaoelyther@gmail.com 2026-06-10T11:22:09+00:00 fa9592ef7de11f8c7042315d9bc20e91a97f679e [ Upstream commit 07a95ec2b54774201fdf4ef7ffb0ca2ab19ed29c ] nl80211_parse_beacon() rejects EMA RNR data when there are fewer RNR entries than MBSSID entries. The rejected RNR allocation has not been attached to the beacon data yet, so free it before returning the error. Fixes: dbbb27e183b1 ("cfg80211: support RNR for EMA AP") Signed-off-by: Zhao Li <enderaoelyther@gmail.com> Link: https://patch.msgid.link/20260610112208.1308-2-enderaoelyther@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 07a95ec2b54774201fdf4ef7ffb0ca2ab19ed29c ]

nl80211_parse_beacon() rejects EMA RNR data when there are fewer RNR
entries than MBSSID entries.

The rejected RNR allocation has not been attached to the beacon data yet,
so free it before returning the error.

Fixes: dbbb27e183b1 ("cfg80211: support RNR for EMA AP")
Signed-off-by: Zhao Li <enderaoelyther@gmail.com>
Link: https://patch.msgid.link/20260610112208.1308-2-enderaoelyther@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: cancel sched scan results work on unregister 2026-08-03T09:15:13+00:00 Cen Zhang zzzccc427@gmail.com 2026-06-19T16:25:42+00:00 3368457b4871ae8f0f88d19c9a3e6270e850ede6 [ Upstream commit edf0730be33696a1bd142792830d392129e495cc ] cfg80211_sched_scan_results() can queue rdev->sched_scan_res_wk from a driver result notification while a scheduled scan request is present. The work callback recovers the containing cfg80211_registered_device and then locks the wiphy and walks the scheduled-scan request list. wiphy_unregister() already makes the wiphy unreachable and drains rdev work items before cfg80211_dev_free() can release the object, but it does not drain sched_scan_res_wk. A queued or running result work item can therefore cross the unregister/free boundary and access freed rdev state. The buggy scenario involves two paths, with each column showing the order within that path: scheduled-scan result path: unregister/free path: 1. cfg80211_sched_scan_results() 1. interface teardown stops and queues rdev->sched_scan_res_wk. removes the scheduled scan request. 2. cfg80211_wq starts the work 2. wiphy_unregister() drains other item and recovers rdev. rdev work items. 3. The worker locks rdev->wiphy 3. cfg80211_dev_free() destroys and and walks rdev state. frees rdev. Cancel sched_scan_res_wk in wiphy_unregister() alongside the other rdev work items. cancel_work_sync() removes a pending result notification and waits for an already running callback, so cfg80211_dev_free() cannot free rdev while this work item is still active. Validation reproduced this kernel report: BUG: KASAN: use-after-free in cfg80211_sched_scan_results_wk+0x4a6/0x530 Workqueue: cfg80211 cfg80211_sched_scan_results_wk [cfg80211] Read of size 8 Call trace: dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 cfg80211_sched_scan_results_wk+0x4a6/0x530 srso_alias_return_thunk+0x5/0xfbef5 __virt_addr_valid+0x224/0x430 kasan_report+0xac/0xe0 lockdep_hardirqs_on_prepare+0xea/0x1a0 process_one_work+0x8d0/0x18f0 (kernel/workqueue.c:3212) lock_is_held_type+0x8f/0x100 worker_thread+0x5ad/0xfd0 __kthread_parkme+0xc6/0x200 kthread+0x31e/0x410 trace_hardirqs_on+0x1a/0x170 ret_from_fork+0x576/0x810 __switch_to+0x57e/0xe20 __switch_to_asm+0x33/0x70 ret_from_fork_asm+0x1a/0x30 Fixes: 807f8a8c3004 ("cfg80211/nl80211: add support for scheduled scans") Assisted-by: Codex:gpt-5.5 Signed-off-by: Cen Zhang <zzzccc427@gmail.com> Link: https://patch.msgid.link/20260619162542.3878296-1-zzzccc427@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit edf0730be33696a1bd142792830d392129e495cc ]

cfg80211_sched_scan_results() can queue rdev->sched_scan_res_wk from a
driver result notification while a scheduled scan request is present. The
work callback recovers the containing cfg80211_registered_device and then
locks the wiphy and walks the scheduled-scan request list.

wiphy_unregister() already makes the wiphy unreachable and drains rdev work
items before cfg80211_dev_free() can release the object, but it does not
drain sched_scan_res_wk. A queued or running result work item can therefore
cross the unregister/free boundary and access freed rdev state.

The buggy scenario involves two paths, with each column showing the order
within that path:

scheduled-scan result path:        unregister/free path:
1. cfg80211_sched_scan_results()   1. interface teardown stops and
   queues rdev->sched_scan_res_wk.    removes the scheduled scan request.
2. cfg80211_wq starts the work     2. wiphy_unregister() drains other
   item and recovers rdev.            rdev work items.
3. The worker locks rdev->wiphy    3. cfg80211_dev_free() destroys and
   and walks rdev state.              frees rdev.

Cancel sched_scan_res_wk in wiphy_unregister() alongside the other rdev
work items. cancel_work_sync() removes a pending result notification and
waits for an already running callback, so cfg80211_dev_free() cannot free
rdev while this work item is still active.

Validation reproduced this kernel report:
BUG: KASAN: use-after-free in cfg80211_sched_scan_results_wk+0x4a6/0x530
Workqueue: cfg80211 cfg80211_sched_scan_results_wk [cfg80211]
Read of size 8
Call trace:
  dump_stack_lvl+0x66/0xa0
  print_report+0xce/0x630
  cfg80211_sched_scan_results_wk+0x4a6/0x530
  srso_alias_return_thunk+0x5/0xfbef5
  __virt_addr_valid+0x224/0x430
  kasan_report+0xac/0xe0
  lockdep_hardirqs_on_prepare+0xea/0x1a0
  process_one_work+0x8d0/0x18f0 (kernel/workqueue.c:3212)
  lock_is_held_type+0x8f/0x100
  worker_thread+0x5ad/0xfd0
  __kthread_parkme+0xc6/0x200
  kthread+0x31e/0x410
  trace_hardirqs_on+0x1a/0x170
  ret_from_fork+0x576/0x810
  __switch_to+0x57e/0xe20
  __switch_to_asm+0x33/0x70
  ret_from_fork_asm+0x1a/0x30

Fixes: 807f8a8c3004 ("cfg80211/nl80211: add support for scheduled scans")
Assisted-by: Codex:gpt-5.5
Signed-off-by: Cen Zhang <zzzccc427@gmail.com>
Link: https://patch.msgid.link/20260619162542.3878296-1-zzzccc427@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: fix grammar in MLO group key error message 2026-07-24T14:02:58+00:00 Louis Kotze loukot@gmail.com 2026-04-14T12:27:28+00:00 dbb66f78931b1ba177e4218cb15bb1af83f0c494 [ Upstream commit 9dcc1af3bbf5441f71a1e51b8d81bdf38a249607 ] The error message emitted by nl80211_validate_key_link_id() when a group key install on an MLO wdev is missing the link ID reads "link ID must for MLO group key", which is missing the words "be set". This makes the error harder to grep and parse in userspace logs, and is reported verbatim by wpa_supplicant via its nl80211 extack relay, e.g.: wpa_supplicant: nl80211: kernel reports: link ID must for MLO group key The sibling error strings in the same helper already use grammatical phrasing ("link ID not allowed for pairwise key", "invalid link ID for MLO group key", "link ID not allowed for non-MLO group key"). Fix this one to match. No functional change. Fixes: e7a7b84e3317 ("wifi: cfg80211: Add link_id parameter to various key operations for MLO") Signed-off-by: Louis Kotze <loukot@gmail.com> Link: https://patch.msgid.link/20260414122728.92234-1-loukot@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 9dcc1af3bbf5441f71a1e51b8d81bdf38a249607 ]

The error message emitted by nl80211_validate_key_link_id() when a group
key install on an MLO wdev is missing the link ID reads "link ID must
for MLO group key", which is missing the words "be set". This makes the
error harder to grep and parse in userspace logs, and is reported
verbatim by wpa_supplicant via its nl80211 extack relay, e.g.:

  wpa_supplicant: nl80211: kernel reports: link ID must for MLO group key

The sibling error strings in the same helper already use grammatical
phrasing ("link ID not allowed for pairwise key", "invalid link ID for
MLO group key", "link ID not allowed for non-MLO group key"). Fix this
one to match.

No functional change.

Fixes: e7a7b84e3317 ("wifi: cfg80211: Add link_id parameter to various key operations for MLO")
Signed-off-by: Louis Kotze <loukot@gmail.com>
Link: https://patch.msgid.link/20260414122728.92234-1-loukot@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: nl80211: reject oversized EMA RNR lists 2026-06-19T11:39:34+00:00 Yuqi Xu xuyuqiabc@gmail.com 2026-05-29T15:25:37+00:00 688fcac7054abc680c0eef753f2bb772cfaf8cf7 commit 4cd92957e8f8cc4ebfe8a5d4203c14c592fde6b1 upstream. nl80211_parse_rnr_elems() stores the parsed element count in a u8-backed cfg80211_rnr_elems::cnt field and uses that count to size the flexible array allocation. Reject nested NL80211_ATTR_EMA_RNR_ELEMS input once the count reaches 255, before incrementing it again. This keeps the parser aligned with the data structure it fills and matches the existing bound check used by nl80211_parse_mbssid_elems(). Fixes: dbbb27e183b1 ("cfg80211: support RNR for EMA AP") Cc: stable@kernel.org Reported-by: Yuan Tan <yuantan098@gmail.com> Reported-by: Zhengchuan Liang <zcliangcn@gmail.com> Reported-by: Xin Liu <bird@lzu.edu.cn> Assisted-by: Codex:gpt-5.4 Signed-off-by: Yuqi Xu <xuyuqiabc@gmail.com> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn> Link: https://patch.msgid.link/20260529152542.1412734-1-n05ec@lzu.edu.cn Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4cd92957e8f8cc4ebfe8a5d4203c14c592fde6b1 upstream.

nl80211_parse_rnr_elems() stores the parsed element count in a
u8-backed cfg80211_rnr_elems::cnt field and uses that count to size
the flexible array allocation.

Reject nested NL80211_ATTR_EMA_RNR_ELEMS input once the count reaches
255, before incrementing it again. This keeps the parser aligned with
the data structure it fills and matches the existing bound check used
by nl80211_parse_mbssid_elems().

Fixes: dbbb27e183b1 ("cfg80211: support RNR for EMA AP")
Cc: stable@kernel.org
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Zhengchuan Liang <zcliangcn@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Assisted-by: Codex:gpt-5.4
Signed-off-by: Yuqi Xu <xuyuqiabc@gmail.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Link: https://patch.msgid.link/20260529152542.1412734-1-n05ec@lzu.edu.cn
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
wifi: cfg80211: advance loop vars in cfg80211_merge_profile() 2026-06-01T15:43:08+00:00 John Walker johnwalker0@gmail.com 2026-05-07T23:07:20+00:00 1ced0f5a851f9cae274545a42a06c459b7fd8881 commit 7666dbb1bacc4ba522b96740cba7283d243d16e1 upstream. cfg80211_merge_profile() reassembles a Multi-BSSID non-transmitted BSS profile that has been split across multiple consecutive MBSSID elements. Its while-loop calls cfg80211_get_profile_continuation(ie, ielen, mbssid_elem, sub_elem) but never advances mbssid_elem or sub_elem inside the body. Each iteration therefore searches for a continuation that follows the same fixed pair; the helper returns the same next_mbssid; and the same next_sub bytes are memcpy()'d into merged_ie at a growing offset until the buffer fills. Advance both mbssid_elem and sub_elem to the just-consumed continuation so the next call to cfg80211_get_profile_continuation() searches for a further continuation beyond it (or returns NULL when none exists). A specially-crafted malicious beacon can take advantage of this bug to cause the kernel to spend an excessive amount of time in cfg80211_merge_profile (up to as much as 2ms per beacon received), which could theoretically be abused in some way. Cc: stable@vger.kernel.org Fixes: fe806e4992c9 ("cfg80211: support profile split between elements") Signed-off-by: John Walker <johnwalker0@gmail.com> Link: https://patch.msgid.link/20260507230720.64783-1-johnwalker0@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7666dbb1bacc4ba522b96740cba7283d243d16e1 upstream.

cfg80211_merge_profile() reassembles a Multi-BSSID non-transmitted BSS
profile that has been split across multiple consecutive MBSSID elements.
Its while-loop calls

	cfg80211_get_profile_continuation(ie, ielen, mbssid_elem, sub_elem)

but never advances mbssid_elem or sub_elem inside the body.  Each
iteration therefore searches for a continuation that follows the same
fixed pair; the helper returns the same next_mbssid; and the same
next_sub bytes are memcpy()'d into merged_ie at a growing offset until
the buffer fills.

Advance both mbssid_elem and sub_elem to the just-consumed continuation
so the next call to cfg80211_get_profile_continuation() searches for a
further continuation beyond it (or returns NULL when none exists).

A specially-crafted malicious beacon can take advantage of this bug
to cause the kernel to spend an excessive amount of time in
cfg80211_merge_profile (up to as much as 2ms per beacon received),
which could theoretically be abused in some way.

Cc: stable@vger.kernel.org
Fixes: fe806e4992c9 ("cfg80211: support profile split between elements")
Signed-off-by: John Walker <johnwalker0@gmail.com>
Link: https://patch.msgid.link/20260507230720.64783-1-johnwalker0@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>