kernel/linux.git/net/wireless/scan.c, branch v6.6.155

wifi: cfg80211: bound element ID read when checking non-inheritance

2026-08-03T09:15:14+00:00

[ 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) Link: https://patch.msgid.link/20260707094828.16465-1-skyexpoc@gmail.com Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin

wifi: cfg80211: advance loop vars in cfg80211_merge_profile()

2026-06-01T15:43:08+00:00

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 Link: https://patch.msgid.link/20260507230720.64783-1-johnwalker0@gmail.com Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman

wifi: cfg80211: fix use-after-free in cmp_bss()

2025-09-09T16:56:21+00:00

[ Upstream commit 26e84445f02ce6b2fe5f3e0e28ff7add77f35e08 ] Following bss_free() quirk introduced in commit 776b3580178f ("cfg80211: track hidden SSID networks properly"), adjust cfg80211_update_known_bss() to free the last beacon frame elements only if they're not shared via the corresponding 'hidden_beacon_bss' pointer. Reported-by: syzbot+30754ca335e6fb7e3092@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=30754ca335e6fb7e3092 Fixes: 3ab8227d3e7d ("cfg80211: refactor cfg80211_bss_update") Signed-off-by: Dmitry Antipov Link: https://patch.msgid.link/20250813135236.799384-1-dmantipov@yandex.ru Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin

wifi: cfg80211: fix out-of-bounds access during multi-link element defragmentation

2025-05-18T06:24:04+00:00

commit 023c1f2f0609218103cbcb48e0104b144d4a16dc upstream. Currently during the multi-link element defragmentation process, the multi-link element length added to the total IEs length when calculating the length of remaining IEs after the multi-link element in cfg80211_defrag_mle(). This could lead to out-of-bounds access if the multi-link element or its corresponding fragment elements are the last elements in the IEs buffer. To address this issue, correctly calculate the remaining IEs length by deducting the multi-link element end offset from total IEs end offset. Cc: stable@vger.kernel.org Fixes: 2481b5da9c6b ("wifi: cfg80211: handle BSS data contained in ML probe responses") Signed-off-by: Veerendranath Jakkam Link: https://patch.msgid.link/20250424-fix_mle_defragmentation_oob_access-v1-1-84412a1743fa@quicinc.com Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman

wifi: cfg80211: adjust allocation of colocated AP data

2025-02-08T08:52:01+00:00

[ Upstream commit 1a0d24775cdee2b8dc14bfa4f4418c930ab1ac57 ] In 'cfg80211_scan_6ghz()', an instances of 'struct cfg80211_colocated_ap' are allocated as if they would have 'ssid' as trailing VLA member. Since this is not so, extra IEEE80211_MAX_SSID_LEN bytes are not needed. Briefly tested with KUnit. Fixes: c8cb5b854b40 ("nl80211/cfg80211: support 6 GHz scanning") Signed-off-by: Dmitry Antipov Link: https://patch.msgid.link/20250113155417.552587-1-dmantipov@yandex.ru Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin

wifi: cfg80211: Handle specific BSSID in 6GHz scanning

2025-02-08T08:52:01+00:00

[ Upstream commit 0fca7784b7a14d4ede64f479662afb98876ec7f8 ] When the scan parameters for a 6GHz scan specify a unicast BSSID address, and the corresponding AP is found in the scan list, add a corresponding entry in the collocated AP list, so this AP would be directly probed even if it was not advertised as a collocated AP. This is needed for handling a scan request that is intended for a ML probe flow, where user space can requests a scan to retrieve information for other links in the AP MLD. Signed-off-by: Ilan Peer Signed-off-by: Gregory Greenman Link: https://lore.kernel.org/r/20230928172905.54b954bc02ad.I1c072793d3d77a4c8fbbc64b4db5cce1bbb00382@changeid Signed-off-by: Johannes Berg Stable-dep-of: 1a0d24775cde ("wifi: cfg80211: adjust allocation of colocated AP data") Signed-off-by: Sasha Levin

wifi: cfg80211: fix UBSAN noise in cfg80211_wext_siwscan()

2024-10-04T14:28:56+00:00

[ Upstream commit a26a5107bc52922cf5f67361e307ad66547b51c7 ] Looking at https://syzkaller.appspot.com/bug?extid=1a3986bbd3169c307819 and running reproducer with CONFIG_UBSAN_BOUNDS, I've noticed the following: [ T4985] UBSAN: array-index-out-of-bounds in net/wireless/scan.c:3479:25 [ T4985] index 164 is out of range for type 'struct ieee80211_channel *[]' <...skipped...> [ T4985] Call Trace: [ T4985] [ T4985] dump_stack_lvl+0x1c2/0x2a0 [ T4985] ? __pfx_dump_stack_lvl+0x10/0x10 [ T4985] ? __pfx__printk+0x10/0x10 [ T4985] __ubsan_handle_out_of_bounds+0x127/0x150 [ T4985] cfg80211_wext_siwscan+0x11a4/0x1260 <...the rest is not too useful...> Even if we do 'creq->n_channels = n_channels' before 'creq->ssids = (void *)&creq->channels[n_channels]', UBSAN treats the latter as off-by-one error. Fix this by using pointer arithmetic rather than an expression with explicit array indexing and use convenient 'struct_size()' to simplify the math here and in 'kzalloc()' above. Fixes: 5ba63533bbf6 ("cfg80211: fix alignment problem in scan request") Signed-off-by: Dmitry Antipov Reviewed-by: Kees Cook Link: https://patch.msgid.link/20240905150400.126386-1-dmantipov@yandex.ru [fix coding style for multi-line calculation] Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin

wifi: cfg80211: make hash table duplicates more survivable

2024-09-08T05:54:47+00:00

[ Upstream commit 7f12e26a194d0043441f870708093d9c2c3bad7d ] Jiazi Li reported that they occasionally see hash table duplicates as evidenced by the WARN_ON() in rb_insert_bss() in this code. It isn't clear how that happens, nor have I been able to reproduce it, but if it does happen, the kernel crashes later, when it tries to unhash the entry that's now not hashed. Try to make this situation more survivable by removing the BSS from the list(s) as well, that way it's fully leaked here (as had been the intent in the hash insert error path), and no longer reachable through the list(s) so it shouldn't be unhashed again later. Link: https://lore.kernel.org/r/20231026013528.GA24122@Jiazi.Li Signed-off-by: Johannes Berg Link: https://msgid.link/20240607181726.36835-2-johannes@sipsolutions.net Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin

wifi: cfg80211: wext: set ssids=NULL for passive scans

2024-07-25T07:50:57+00:00

commit 0941772342d59e48733131ac3a202fa1a4d832e9 upstream. In nl80211, we always set the ssids of a scan request to NULL when n_ssids==0 (passive scan). Drivers have relied on this behaviour in the past, so we fixed it in 6 GHz scan requests as well, and added a warning so we'd have assurance the API would always be called that way. syzbot found that wext doesn't ensure that, so we reach the check and trigger the warning. Fix the wext code to set the ssids pointer to NULL when there are none. Reported-by: syzbot+cd6135193ba6bb9ad158@syzkaller.appspotmail.com Fixes: f7a8b10bfd61 ("wifi: cfg80211: fix 6 GHz scan request building") Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman

wifi: cfg80211: wext: add extra SIOCSIWSCAN data check

2024-07-25T07:50:47+00:00

[ Upstream commit 6ef09cdc5ba0f93826c09d810c141a8d103a80fc ] In 'cfg80211_wext_siwscan()', add extra check whether number of channels passed via 'ioctl(sock, SIOCSIWSCAN, ...)' doesn't exceed IW_MAX_FREQUENCIES and reject invalid request with -EINVAL otherwise. Reported-by: syzbot+253cd2d2491df77c93ac@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=253cd2d2491df77c93ac Signed-off-by: Dmitry Antipov Link: https://msgid.link/20240531032010.451295-1-dmantipov@yandex.ru Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin