linux-stable.git/net/wireless/scan.c, branch linux-5.4.y Linux kernel stable tree wifi: cfg80211: fix use-after-free in cmp_bss() 2025-09-09T16:43:56+00:00 Dmitry Antipov dmantipov@yandex.ru 2025-08-13T13:52:36+00:00 a8bb681e879ca3c9f722aa08d3d7ae41c42a8807 [ 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 <dmantipov@yandex.ru> Link: https://patch.msgid.link/20250813135236.799384-1-dmantipov@yandex.ru Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <dmantipov@yandex.ru>
Link: https://patch.msgid.link/20250813135236.799384-1-dmantipov@yandex.ru
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: fix UBSAN noise in cfg80211_wext_siwscan() 2024-11-08T15:20:27+00:00 Dmitry Antipov dmantipov@yandex.ru 2024-09-05T15:04:00+00:00 7d38d0cea33350cb1cc232c7c9ca8663d7827325 [ 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] <TASK> [ 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 <dmantipov@yandex.ru> Reviewed-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20240905150400.126386-1-dmantipov@yandex.ru [fix coding style for multi-line calculation] Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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]  <TASK>
[ 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 <dmantipov@yandex.ru>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20240905150400.126386-1-dmantipov@yandex.ru
[fix coding style for multi-line calculation]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: make hash table duplicates more survivable 2024-09-12T09:03:50+00:00 Johannes Berg johannes.berg@intel.com 2024-06-07T18:17:17+00:00 d7fc80b7f80111f2be42cc7123c9e528c391180c [ 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 <johannes.berg@intel.com> Link: https://msgid.link/20240607181726.36835-2-johannes@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <johannes.berg@intel.com>
Link: https://msgid.link/20240607181726.36835-2-johannes@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: wext: add extra SIOCSIWSCAN data check 2024-07-27T08:38:30+00:00 Dmitry Antipov dmantipov@yandex.ru 2024-05-31T03:20:10+00:00 de5fcf757e33596eed32de170ce5a93fa44dd2ac [ 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 <dmantipov@yandex.ru> Link: https://msgid.link/20240531032010.451295-1-dmantipov@yandex.ru Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <dmantipov@yandex.ru>
Link: https://msgid.link/20240531032010.451295-1-dmantipov@yandex.ru
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: fix RCU dereference in __cfg80211_bss_update 2024-02-23T07:25:03+00:00 Edward Adam Davis eadavis@qq.com 2024-01-03T12:13:51+00:00 12f58dce48cfaf6a89d8106c2e33a4a3c4b217dd [ Upstream commit 1184950e341c11b6f82bc5b59564411d9537ab27 ] Replace rcu_dereference() with rcu_access_pointer() since we hold the lock here (and aren't in an RCU critical section). Fixes: 32af9a9e1069 ("wifi: cfg80211: free beacon_ies when overridden from hidden BSS") Reported-and-tested-by: syzbot+864a269c27ee06b58374@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis <eadavis@qq.com> Link: https://msgid.link/tencent_BF8F0DF0258C8DBF124CDDE4DD8D992DCF07@qq.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1184950e341c11b6f82bc5b59564411d9537ab27 ]

Replace rcu_dereference() with rcu_access_pointer() since we hold
the lock here (and aren't in an RCU critical section).

Fixes: 32af9a9e1069 ("wifi: cfg80211: free beacon_ies when overridden from hidden BSS")
Reported-and-tested-by: syzbot+864a269c27ee06b58374@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Link: https://msgid.link/tencent_BF8F0DF0258C8DBF124CDDE4DD8D992DCF07@qq.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: free beacon_ies when overridden from hidden BSS 2024-02-23T07:25:00+00:00 Benjamin Berg benjamin.berg@intel.com 2023-12-20T11:41:41+00:00 52240224e74aaf6a699c0ca886aa30317bb7919b [ Upstream commit 32af9a9e1069e55bc02741fb00ac9d0ca1a2eaef ] This is a more of a cosmetic fix. The branch will only be taken if proberesp_ies is set, which implies that beacon_ies is not set unless we are connected to an AP that just did a channel switch. And, in that case we should have found the BSS in the internal storage to begin with. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Reviewed-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com> Link: https://msgid.link/20231220133549.b898e22dadff.Id8c4c10aedd176ef2e18a4cad747b299f150f9df@changeid Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 32af9a9e1069e55bc02741fb00ac9d0ca1a2eaef ]

This is a more of a cosmetic fix. The branch will only be taken if
proberesp_ies is set, which implies that beacon_ies is not set unless we
are connected to an AP that just did a channel switch. And, in that case
we should have found the BSS in the internal storage to begin with.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20231220133549.b898e22dadff.Id8c4c10aedd176ef2e18a4cad747b299f150f9df@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: rewrite merging of inherited elements 2023-07-27T06:37:10+00:00 Benjamin Berg benjamin.berg@intel.com 2023-06-16T06:54:03+00:00 76d5bda2c3af54f471e187f5b59f3af7a795b95f [ Upstream commit dfd9aa3e7a456d57b18021d66472ab7ff8373ab7 ] The cfg80211_gen_new_ie function merges the IEs using inheritance rules. Rewrite this function to fix issues around inheritance rules. In particular, vendor elements do not require any special handling, as they are either all inherited or overridden by the subprofile. Also, add fragmentation handling as this may be needed in some cases. This also changes the function to not require making a copy. The new version could be optimized a bit by explicitly tracking which IEs have been handled already rather than looking that up again every time. Note that a small behavioural change is the removal of the SSID special handling. This should be fine for the MBSSID element, as the SSID must be included in the subelement. Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning") Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Signed-off-by: Gregory Greenman <gregory.greenman@intel.com> Link: https://lore.kernel.org/r/20230616094949.bc6152e146db.I2b5f3bc45085e1901e5b5192a674436adaf94748@changeid Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit dfd9aa3e7a456d57b18021d66472ab7ff8373ab7 ]

The cfg80211_gen_new_ie function merges the IEs using inheritance rules.
Rewrite this function to fix issues around inheritance rules. In
particular, vendor elements do not require any special handling, as they
are either all inherited or overridden by the subprofile.
Also, add fragmentation handling as this may be needed in some cases.

This also changes the function to not require making a copy. The new
version could be optimized a bit by explicitly tracking which IEs have
been handled already rather than looking that up again every time.

Note that a small behavioural change is the removal of the SSID special
handling. This should be fine for the MBSSID element, as the SSID must
be included in the subelement.

Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning")
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230616094949.bc6152e146db.I2b5f3bc45085e1901e5b5192a674436adaf94748@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: fix buffer overflow in elem comparison 2022-12-08T10:23:03+00:00 Johannes Berg johannes.berg@intel.com 2022-11-25T11:36:57+00:00 f5c2ec288a865dbe3706b09bed12302e9f6d696b [ Upstream commit 9f16b5c82a025cd4c864737409234ddc44fb166a ] For vendor elements, the code here assumes that 5 octets are present without checking. Since the element itself is already checked to fit, we only need to check the length. Reported-and-tested-by: Sönke Huster <shuster@seemoo.tu-darmstadt.de> Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 9f16b5c82a025cd4c864737409234ddc44fb166a ]

For vendor elements, the code here assumes that 5 octets
are present without checking. Since the element itself is
already checked to fit, we only need to check the length.

Reported-and-tested-by: Sönke Huster <shuster@seemoo.tu-darmstadt.de>
Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: silence a sparse RCU warning 2022-11-25T16:42:04+00:00 Johannes Berg johannes.berg@intel.com 2022-10-13T17:41:51+00:00 1c8d06631749c0056c7d29fa18c078a4569b0050 [ Upstream commit 03c0ad4b06c3566de624b4f4b78ac1a5d1e4c8e7 ] All we're going to do with this pointer is assign it to another __rcu pointer, but sparse can't see that, so use rcu_access_pointer() to silence the warning here. Fixes: c90b93b5b782 ("wifi: cfg80211: update hidden BSSes to avoid WARN_ON") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 03c0ad4b06c3566de624b4f4b78ac1a5d1e4c8e7 ]

All we're going to do with this pointer is assign it to
another __rcu pointer, but sparse can't see that, so
use rcu_access_pointer() to silence the warning here.

Fixes: c90b93b5b782 ("wifi: cfg80211: update hidden BSSes to avoid WARN_ON")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
wifi: cfg80211: update hidden BSSes to avoid WARN_ON 2022-10-15T05:54:41+00:00 Johannes Berg johannes.berg@intel.com 2022-10-05T21:11:43+00:00 9389750ac6b0d462703629322c596a516a8f80dc commit c90b93b5b782891ebfda49d4e5da36632fefd5d1 upstream. When updating beacon elements in a non-transmitted BSS, also update the hidden sub-entries to the same beacon elements, so that a future update through other paths won't trigger a WARN_ON(). The warning is triggered because the beacon elements in the hidden BSSes that are children of the BSS should always be the same as in the parent. Reported-by: Sönke Huster <shuster@seemoo.tu-darmstadt.de> Tested-by: Sönke Huster <shuster@seemoo.tu-darmstadt.de> Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c90b93b5b782891ebfda49d4e5da36632fefd5d1 upstream.

When updating beacon elements in a non-transmitted BSS,
also update the hidden sub-entries to the same beacon
elements, so that a future update through other paths
won't trigger a WARN_ON().

The warning is triggered because the beacon elements in
the hidden BSSes that are children of the BSS should
always be the same as in the parent.

Reported-by: Sönke Huster <shuster@seemoo.tu-darmstadt.de>
Tested-by: Sönke Huster <shuster@seemoo.tu-darmstadt.de>
Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>