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Filename Latest commit message Latest commit date
Nikita Zhandarovich 62b1a9bbfe wifi: cfg80211: regulatory: improve invalid hints checking
commit 59b348be7597c4a9903cb003c69e37df20c04a30 upstream.

Syzbot keeps reporting an issue [1] that occurs when erroneous symbols
sent from userspace get through into user_alpha2[] via
regulatory_hint_user() call. Such invalid regulatory hints should be
rejected.

While a sanity check from commit 47caf685a685 ("cfg80211: regulatory:
reject invalid hints") looks to be enough to deter these very cases,
there is a way to get around it due to 2 reasons.

1) The way isalpha() works, symbols other than latin lower and
upper letters may be used to determine a country/domain.
For instance, greek letters will also be considered upper/lower
letters and for such characters isalpha() will return true as well.
However, ISO-3166-1 alpha2 codes should only hold latin
characters.

2) While processing a user regulatory request, between
reg_process_hint_user() and regulatory_hint_user() there happens to
be a call to queue_regulatory_request() which modifies letters in
request->alpha2[] with toupper(). This works fine for latin symbols,
less so for weird letter characters from the second part of _ctype[].

Syzbot triggers a warning in is_user_regdom_saved() by first sending
over an unexpected non-latin letter that gets malformed by toupper()
into a character that ends up failing isalpha() check.

Prevent this by enhancing is_an_alpha2() to ensure that incoming
symbols are latin letters and nothing else.

[1] Syzbot report:
------------[ cut here ]------------
Unexpected user alpha2: A�
WARNING: CPU: 1 PID: 964 at net/wireless/reg.c:442 is_user_regdom_saved net/wireless/reg.c:440 [inline]
WARNING: CPU: 1 PID: 964 at net/wireless/reg.c:442 restore_alpha2 net/wireless/reg.c:3424 [inline]
WARNING: CPU: 1 PID: 964 at net/wireless/reg.c:442 restore_regulatory_settings+0x3c0/0x1e50 net/wireless/reg.c:3516
Modules linked in:
CPU: 1 UID: 0 PID: 964 Comm: kworker/1:2 Not tainted 6.12.0-rc5-syzkaller-00044-gc1e939a21eb1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events_power_efficient crda_timeout_work
RIP: 0010:is_user_regdom_saved net/wireless/reg.c:440 [inline]
RIP: 0010:restore_alpha2 net/wireless/reg.c:3424 [inline]
RIP: 0010:restore_regulatory_settings+0x3c0/0x1e50 net/wireless/reg.c:3516
...
Call Trace:
 <TASK>
 crda_timeout_work+0x27/0x50 net/wireless/reg.c:542
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Reported-by: syzbot+e10709ac3c44f3d4e800@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=e10709ac3c44f3d4e800
Fixes: 09d989d179 ("cfg80211: add regulatory hint disconnect support")
Cc: stable@kernel.org
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Link: https://patch.msgid.link/20250228134659.1577656-1-n.zhandarovich@fintech.ru
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 12:43:28 +01:00
arch x86/cpu: Properly parse CPUID leaf 0x2 TLB descriptor 0x63 2025-03-13 12:43:27 +01:00
block partitions: mac: fix handling of bogus partition table 2025-03-13 12:43:16 +01:00
certs
crypto crypto: testmgr - some more fixes to RSA test vectors 2025-03-13 12:43:21 +01:00
Documentation dt-bindings: mmc: controller: clarify the address-cells description 2025-03-13 12:42:53 +01:00
drivers platform/x86: thinkpad_acpi: Add battery quirk for ThinkPad X131e 2025-03-13 12:43:27 +01:00
fs btrfs: avoid monopolizing a core when activating a swap file 2025-03-13 12:43:19 +01:00
include net: extract port range fields from fl_flow_key 2025-03-13 12:43:23 +01:00
init initramfs: avoid filename buffer overrun 2024-12-14 19:44:21 +01:00
ipc
kernel acct: perform last write from workqueue 2025-03-13 12:43:26 +01:00
lib lib: string_helpers: silence snprintf() output truncation warning 2024-12-14 19:44:39 +01:00
LICENSES
mm memcg: fix soft lockup in the OOM process 2025-03-13 12:43:21 +01:00
net wifi: cfg80211: regulatory: improve invalid hints checking 2025-03-13 12:43:28 +01:00
samples samples/bpf: Fix a resource leak 2024-12-14 19:44:50 +01:00
scripts kbuild: Move -Wenum-enum-conversion to W=2 2025-03-13 12:43:09 +01:00
security ima: Fix use-after-free on a dentry's dname.name 2025-03-13 12:43:19 +01:00
sound ALSA: hda/realtek: update ALC222 depop optimize 2025-03-13 12:43:27 +01:00
tools perf bench: Fix undefined behavior in cmpworker() 2025-03-13 12:43:08 +01:00
usr
virt KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow status 2024-12-19 18:05:04 +01:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore Remove *.orig pattern from .gitignore 2024-11-08 16:20:33 +01:00
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile kbuild: userprogs: use correct lld when linking through clang 2025-03-13 12:43:04 +01:00
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