kernel/linux.git/net/mac80211/debugfs.c, branch v6.19.11

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

2026-03-25T10:13:23+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: remove tx_handlers_drop debugfs stats

2025-09-19T09:50:48+00:00

Commit 906a5a8c7152 ("wifi: mac80211: add tx_handlers_drop statistics to ethtool") added a tx_handlers_drop counter to ethtool stats. During review [1], Johannes noted that the existing debugfs counter is now redundant. Remove the debugfs stat to avoid duplication and streamline statistics reporting. Link: https://lore.kernel.org/linux-wireless/ce5f2bd899caa2de32f36ce554d9cada073979c0.camel@sipsolutions.net/ # [1] Signed-off-by: Sarika Sharma Link: https://patch.msgid.link/20250918040846.4032734-1-quic_sarishar@quicinc.com Signed-off-by: Johannes Berg

wifi: mac80211: Remove redundant rcu_read_lock/unlock() in spin_lock

2025-09-19T09:48:14+00:00

Since commit a8bb74acd8efe ("rcu: Consolidate RCU-sched update-side function definitions") there is no difference between rcu_read_lock(), rcu_read_lock_bh() and rcu_read_lock_sched() in terms of RCU read section and the relevant grace period. That means that spin_lock(), which implies rcu_read_lock_sched(), also implies rcu_read_lock(). There is no need no explicitly start a RCU read section if one has already been started implicitly by spin_lock(). Simplify the code and remove the inner rcu_read_lock() invocation. Cc: Johannes Berg Signed-off-by: pengdonglin Signed-off-by: pengdonglin Link: https://patch.msgid.link/20250916044735.2316171-11-dolinux.peng@gmail.com Signed-off-by: Johannes Berg

wifi: mac80211: remove DISALLOW_PUNCTURING_5GHZ code

2025-07-09T09:52:36+00:00

Since iwlwifi was the only driver using this and no longer does, we can remove all this code. Signed-off-by: Johannes Berg Signed-off-by: Miri Korenblit Link: https://patch.msgid.link/20250609213231.4dff5fb8890f.Ie531f912b252a0042c18c0734db50c3afe1adfb5@changeid Signed-off-by: Johannes Berg

wifi: mac80211: add strict mode disabling workarounds

2025-02-11T10:59:06+00:00

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

wifi: mac80211: use wiphy guard

2024-12-04T15:10:52+00:00

The wiphy guard simplifies some code here, so use it. Reviewed-by: Jeff Johnson Signed-off-by: Johannes Berg Link: https://patch.msgid.link/20241122094225.cea65b2d2fd4.Icc168c4bbeddec98ea096aee9077211a7b88b69e@changeid Signed-off-by: Johannes Berg

wifi: mac80211: convert debugfs files to short fops

2024-10-23T14:47:07+00:00

Given the large size of the regular struct file_operations, save a lot of space with the newly added short fops for debugfs. Link: https://patch.msgid.link/20241022151838.2f6de3ea3ecc.I45657e6a8415d796ec95c95becc9efb377ee3be6@changeid Signed-off-by: Johannes Berg

wifi: mac80211: add flag to opt out of virtual monitor support

2024-10-23T14:45:43+00:00

This is useful for multi-radio devices that are capable of monitoring on multiple channels simultanenously. When this flag is set, each monitor interface is passed to the driver individually and can have a configured channel. The vif mac address for non-active monitor interfaces is cleared, in order to allow the driver to tell them apart from active ones. Signed-off-by: Felix Fietkau Link: https://patch.msgid.link/3c55505ee0cf0a5f141fbcb30d1e8be8d9f40373.1728462320.git-series.nbd@nbd.name Signed-off-by: Johannes Berg

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