From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f169.google.com (mail-oi1-f169.google.com [209.85.167.169]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E36D0239E7F for ; Mon, 26 Jan 2026 18:00:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.169 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769450423; cv=none; b=dv8hdCqgAfLxIXxWu+CU7cza/J0zViBCu0nQjvpXJomryj53lPxv/AY8U+rp6GygVjY775GKjbRgnpJp+rAr8Mv5lUxG7jUi9meDih5+9Pfmu55rGtfJQeIHD47G4ldvqdjddbgYdjfRKWElXcW7MwtqXV4lqLgkDFrCWhYr8EA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769450423; c=relaxed/simple; bh=m8lCZYrtv6Qoifxxy6t6zkh7mSRUSw2fRiy0Gt/9m2Q=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=FPjiW6cyp+iwPUx/z2NsL7ASzMzy1/fOmV4rVwv0oW07zf60VGvXShkNmFeEbkQSC77ixwk7syhDxvlOLJQOikM5uundxaEbiyYD3X1TxZrjQ6Se/wb+3eyPG5sxYkf6OVghsQq3hfBp8EY5VcI+1NjXmNDRNVhjMl64KMZZltc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=kernel.org; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.167.169 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-oi1-f169.google.com with SMTP id 5614622812f47-45c958d480aso1423607b6e.1 for ; Mon, 26 Jan 2026 10:00:20 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769450419; x=1770055219; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=MtP8Go2M3C9++DiSDULRDE+5Pn2l5CFyfesMiTCa6/g=; b=kh4Of84PN3flYRnZO/EKnzxw6maRpNewBfzbtuxzH3O2uizy5XdV3xmuYTnXkHVRqO 6nt/kpfF1jk9TuvVqBkfytkRJ0Pzk2sMNUXweUCIZlrChP8he7Y42rLLIK9b24pKBqLN +izuH+HdFObYjymwD0rLX1qX3F27qG3bIA/vwV4ASmHCCLVh83jQR1oh6hPy3GKeM57x SYO49nlcORh5IpxbefL1TGRaTZShG4ahc3ShaOBlZUKm+z//6N8Tk6jOfjrj4QkvrM1Q ErQcplJyfG2V5bzcGxMoDyuaxWYkDCoj6d+FA8+3iIgEQeSovsB+ZvcVv8nXQGAwMA9n XXCQ== X-Forwarded-Encrypted: i=1; AJvYcCXOOgKdnUlGaBGnVzfPvbAVqkPHdlB5Nv/mWVH9AXlTSzdJl7EdyAMkVWJcdmFw77BgfcMTC7E5mVrU0C0eDA==@vger.kernel.org X-Gm-Message-State: AOJu0Yy57Rtsl71OsU0Ih9S2Pgmf/zC8OFDUoxGZaVJHe7WOTDF83qq1 qCr8uS2KOYlSGTeEgoYEwV+Nm7Pw40ng3Yy7cBvDRrIrh6wC7kcwUNKs X-Gm-Gg: AZuq6aJsJHBIZvOOeT41jV4UpIER5u3E7olSi4e/AxRgPLltjPOCZAacaPyE4DBFmXN pD297xjnDltNbJRLrdumPCJ9mpnkRETBjuTerm0ZPv41iUfpCcanVmaBXbvvqoE4Yfe1kQ9/2rj 5w4P3k72IVtReI79p27dCSHV4xCMu28pADNXvOfSPx/cDSPXkI5el5kp9dSGSZbbUDdXam318Jt QEBJCWf50t5+1oCokGfRh3u+ZhtuRGq+HTVzjq6SQGxP83bMgYqUTP/0swBdwcyT2fkypmMPF5h 6u+qoFJ97wTaCjytnrMAiANTRYht59C7rXZ7DF6u7wRqkFGvorqFyjrtQbDinLXov2ACzQidoTO ug15I3kQGiyiQegvyKJo/5MOX0Ub9+91YTYX6+yP5SFNA6yYejJBTwXN2ZUf3FT6ud0d6x79lRc yaknlLugG9yrBc4pBMmYA0RWJpGKh/NkoIpaWkZ/gyx+pK0HxTfZ3I8XM4oTP159rBPwjmDbZxK qWVhmW6lg== X-Received: by 2002:a05:6830:3143:b0:7c6:d0b2:8eb6 with SMTP id 46e09a7af769-7d1701d7c73mr2647850a34.15.1769450419085; Mon, 26 Jan 2026 10:00:19 -0800 (PST) Received: from sean-HP-EliteBook-830-G6.. (65-36-108-159.dyn.grandenetworks.net. [65.36.108.159]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-7d15b3d31d4sm8173838a34.21.2026.01.26.10.00.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jan 2026 10:00:18 -0800 (PST) From: Sean Wang To: nbd@nbd.name, lorenzo@kernel.org Cc: allan.wang@mediatek.com, quan.zhou@mediatek.com, leon.yen@mediatek.com, linux-wireless@vger.kernel.org, linux-mediatek@lists.infradead.org, Sean Wang Subject: [PATCH] wifi: mt76: mt7921: fix potential deadlock in mt7921_roc_abort_sync Date: Mon, 26 Jan 2026 12:00:13 -0600 Message-ID: <20260126180013.8167-1-sean.wang@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Sean Wang roc_abort_sync() can deadlock with roc_work(). roc_work() holds dev->mt76.mutex, while cancel_work_sync() waits for roc_work() to finish. If the caller already owns the same mutex, both sides block and no progress is possible. This deadlock can occur during station removal when mt76_sta_state() -> mt76_sta_remove() -> mt7921_mac_sta_remove() -> mt7921_roc_abort_sync() invokes cancel_work_sync() while roc_work() is still running and holding dev->mt76.mutex. This avoids the mutex deadlock and preserves exactly-once work ownership. Fixes: 352d966126e6 ("wifi: mt76: mt7921: fix a potential association failure upon resuming") Co-developed-by: Quan Zhou Signed-off-by: Quan Zhou Signed-off-by: Sean Wang --- drivers/net/wireless/mediatek/mt76/mt7921/main.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/main.c b/drivers/net/wireless/mediatek/mt76/mt7921/main.c index 05793a786644..ddb81ca6bda0 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/main.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/main.c @@ -371,12 +371,15 @@ void mt7921_roc_abort_sync(struct mt792x_dev *dev) { struct mt792x_phy *phy = &dev->phy; + if (!test_and_clear_bit(MT76_STATE_ROC, &phy->mt76->state)) + return; + timer_delete_sync(&phy->roc_timer); - cancel_work_sync(&phy->roc_work); - if (test_and_clear_bit(MT76_STATE_ROC, &phy->mt76->state)) - ieee80211_iterate_interfaces(mt76_hw(dev), - IEEE80211_IFACE_ITER_RESUME_ALL, - mt7921_roc_iter, (void *)phy); + cancel_work(&phy->roc_work); + + ieee80211_iterate_interfaces(mt76_hw(dev), + IEEE80211_IFACE_ITER_RESUME_ALL, + mt7921_roc_iter, (void *)phy); } EXPORT_SYMBOL_GPL(mt7921_roc_abort_sync); -- 2.43.0