kernel/linux.git/net/mac80211/debugfs.c, branch v6.12.80

wifi: mac80211: Fix static_branch_dec() underflow for aql_disable.

2026-03-25T10:08:51+00:00

[ Upstream commit b94ae8e0d5fe1bdbbfdc3854ff6ce98f6876a828 ] syzbot reported static_branch_dec() underflow in aql_enable_write(). [0] The problem is that aql_enable_write() does not serialise concurrent write()s to the debugfs. aql_enable_write() checks static_key_false(&aql_disable.key) and later calls static_branch_inc() or static_branch_dec(), but the state may change between the two calls. aql_disable does not need to track inc/dec. Let's use static_branch_enable() and static_branch_disable(). [0]: val == 0 WARNING: kernel/jump_label.c:311 at __static_key_slow_dec_cpuslocked.part.0+0x107/0x120 kernel/jump_label.c:311, CPU#0: syz.1.3155/20288 Modules linked in: CPU: 0 UID: 0 PID: 20288 Comm: syz.1.3155 Tainted: G U L syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:__static_key_slow_dec_cpuslocked.part.0+0x107/0x120 kernel/jump_label.c:311 Code: f2 c9 ff 5b 5d c3 cc cc cc cc e8 54 f2 c9 ff 48 89 df e8 ac f9 ff ff eb ad e8 45 f2 c9 ff 90 0f 0b 90 eb a2 e8 3a f2 c9 ff 90 <0f> 0b 90 eb 97 48 89 df e8 5c 4b 33 00 e9 36 ff ff ff 0f 1f 80 00 RSP: 0018:ffffc9000b9f7c10 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffffffff9b3e5d40 RCX: ffffffff823c57b4 RDX: ffff8880285a0000 RSI: ffffffff823c5846 RDI: ffff8880285a0000 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000000a R13: 1ffff9200173ef88 R14: 0000000000000001 R15: ffffc9000b9f7e98 FS: 00007f530dd726c0(0000) GS:ffff8881245e3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000001140 CR3: 000000007cc4a000 CR4: 00000000003526f0 Call Trace: __static_key_slow_dec_cpuslocked kernel/jump_label.c:297 [inline] __static_key_slow_dec kernel/jump_label.c:321 [inline] static_key_slow_dec+0x7c/0xc0 kernel/jump_label.c:336 aql_enable_write+0x2b2/0x310 net/mac80211/debugfs.c:343 short_proxy_write+0x133/0x1a0 fs/debugfs/file.c:383 vfs_write+0x2aa/0x1070 fs/read_write.c:684 ksys_pwrite64 fs/read_write.c:793 [inline] __do_sys_pwrite64 fs/read_write.c:801 [inline] __se_sys_pwrite64 fs/read_write.c:798 [inline] __x64_sys_pwrite64+0x1eb/0x250 fs/read_write.c:798 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f530cf9aeb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f530dd72028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007f530d215fa0 RCX: 00007f530cf9aeb9 RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000010 RBP: 00007f530d008c1f R08: 0000000000000000 R09: 0000000000000000 R10: 4200000000000005 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f530d216038 R14: 00007f530d215fa0 R15: 00007ffde89fb978 Fixes: e908435e402a ("mac80211: introduce aql_enable node in debugfs") Reported-by: syzbot+feb9ce36a95341bb47a4@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/69a8979e.a70a0220.b118c.0025.GAE@google.com/ Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260306072405.3649474-1-kuniyu@google.com Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin

wifi: mac80211: add strict mode disabling workarounds

2025-04-20T08:15:17+00:00

[ Upstream commit 3ad4fce66e4f9d82abfc366707757e29cc14a9d2 ] Add a strict mode where we disable certain workarounds and have additional checks such as, for now, that VHT capabilities from association response match those from beacon/probe response. We can extend the checks in the future. Make it an opt-in setting by the driver so it can be set there in some driver-specific way, for example. Also allow setting this one hw flag through the hwflags debugfs, by writing a new strict=0 or strict=1 value. Signed-off-by: Johannes Berg Reviewed-by: Ilan Peer Signed-off-by: Miri Korenblit Link: https://patch.msgid.link/20250205110958.5cecb0469479.I4a69617dc60ba0d6308416ffbc3102cfd08ba068@changeid Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin

wifi: mac80211: remove DEAUTH_NEED_MGD_TX_PREP

2024-06-28T07:56:30+00:00

This flag is annoying because it puts a lot of logic into mac80211 that could just as well be in the driver (only iwlmvm uses it) and the implementation is also broken for MLO. Remove the flag in favour of calling drv_mgd_prepare_tx() without any conditions even for the deauth-while-assoc case. The drivers that implement it can take the appropriate actions, which for the only user of DEAUTH_NEED_MGD_TX_PREP (iwlmvm) is a bit more tricky than the implementation in mac80211 is anyway, and all others have no need and can just exit if info->was_assoc is set. Reviewed-by: Miriam Rachel Korenblit Link: https://patch.msgid.link/20240627132527.94924bcc9c9e.I328a219e45f2e2724cd52e75bb9feee3bf21a463@changeid Signed-off-by: Johannes Berg

wifi: mac80211: add flag to disallow puncturing in 5 GHz

2024-03-25T14:38:13+00:00

Some devices may not be capable of handling puncturing in 5 GHz only (vs. the current flag that just removes puncturing support completely). Add a flag to support such devices: check and then downgrade the channel width if needed. Signed-off-by: Johannes Berg Signed-off-by: Miri Korenblit Link: https://msgid.link/20240318184907.49759510da7d.I12c5a61f0be512e0c4e574c2f794ef4b37ecaf6b@changeid Signed-off-by: Johannes Berg

wifi: mac80211: introduce a feature flag for quiet in CSA

2024-03-04T13:33:58+00:00

When doing CSA in multi-link, there really isn't a need to stop transmissions entirely. Add a feature flag for drivers to indicate they can handle quiet in CSA (be it by parsing themselves, or by implementing drv_pre_channel_switch()), to make that possible. Also clean up the csa_block_tx handling: it clearly cannot handle multi-link due to the way queues are stopped, move it to the sdata. Drivers should be doing it themselves for working properly during CSA in MLO anyway. Also rename it to indicate that it reflects TX was blocked at mac80211. Reviewed-by: Miriam Rachel Korenblit Link: https://msgid.link/20240228095719.258439191541.I2469d206e2bf5cb244cfde2b4bbc2ae6d1cd3dd9@changeid Signed-off-by: Johannes Berg

wifi: mac80211: add a flag to disallow puncturing

2023-12-12T09:37:00+00:00

There may be cases where puncturing isn't possible, and a connection needs to be downgraded. Add a hardware flag to support this. This is likely temporary: it seems we will need to move puncturing to the chandef/channel context. Signed-off-by: Johannes Berg Reviewed-by: Gregory Greenman Signed-off-by: Miri Korenblit Link: https://msgid.link/20231211085121.c1e89ea55e93.I37b8ca0ee64d5d7699e351785a9010afc106da3c@changeid Signed-off-by: Johannes Berg

wifi: mac80211: remove sta_mtx

2023-09-11T09:27:22+00:00

We now hold the wiphy mutex everywhere that we use or needed the sta_mtx, so we don't need this mutex any more. Remove it. Most of this change was done automatically with spatch. Signed-off-by: Johannes Berg

wifi: mac80211: debugfs: lock wiphy instead of RTNL

2023-09-11T09:27:18+00:00

Since we no longer really use the RTNL, there's no point in locking it here. Most drivers don't really need to have any locks here anyway, and the rest are probably completely broken, but it's a debugfs-only callback so it really doesn't matter much. Signed-off-by: Johannes Berg

wifi: mac80211: remove return value check of debugfs_create_dir()

2023-04-20T09:46:07+00:00

Smatch complains that: debugfs_hw_add() warn: 'statsd' is an error pointer or valid Debugfs checks are generally not supposed to be checked for errors and it is not necessary here. Just delete the dead code. Signed-off-by: Yingsha Xu Reviewed-by: Dongliang Mu Link: https://lore.kernel.org/r/20230419104548.30124-1-ysxu@hust.edu.cn Signed-off-by: Johannes Berg

wifi: mac80211: Drop support for TX push path

2022-10-10T09:06:14+00:00

All drivers are now using mac80211 internal queues (iTXQs). Drop mac80211 internal support for the old push path. Signed-off-by: Alexander Wetzel Signed-off-by: Johannes Berg