From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792790166; b=ocQqgBRh2LQsx2GjjHH1DevW/qq53D7qH4d87frjXoORq2bFlbX3579KKDnLnflkxml1 8vsyg/zPTz9l75L5Do9N5BKlrWqvkhsrqLBzB6z+HG4R0C2KTExH5c9BIAP5KOjO/6Th6 GwwDBq2AasWbaFh7EAMwtPzYH+avTEWg7BEhx+Jg7l6SRx+bJmr7HxVm5K45rW2mk+tYi zGtwudrAa8yM9MyDrsbPpGeGjB+rzgc36njI9b6nhm0T5WO2u9dPg0J7O24s8cH6GNtE/ p+ps0/Yp2//FtgI/aPZh6zLkyE35rg9HUTmy0uWswLVg2CrYGSDwwdRy+3k28+/K6ww== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792790166; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=xTsiCZc657L7oQhql4ts4mXSow+otBZUp5bcJ6kNE4o=; b=44vQp+dTB9gjQ+zJz/LN9k7y7U6pg0T+IOuUEd8Ec3YXC54MGCTgJjRMWldW9rFnxOb0 M2Fw+Qu/jnURbzqOnWtFMWOqW1mtDUI5W+x1O5qdnSMJCIxZe2cBJBW44D/yTJFn928to Rzzg+S8E7jO7Y7KVUItj34E/70am7LO6bwDJ1BGGZCE/BzFLGEdvisi4agU7mYKpZYD1l f6uzdzxxJfQ6KrpUuk0EN6UM3/xOxRUUQSdO3UJcfEBbcCS/Unaraw1lEZifJg7RtgAMM yQnGNIKas5xbvA6tvii/DiIyyTrH9dfpDX088gb+kNIw/xdP417XaT5GXbV7LU7H1/w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Cy8LBVSs; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 78588606A31A; Fri, 23 Oct 2026 21:16:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Cy8LBVSs Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15ED91F01825; Fri, 23 Oct 2026 21:16:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792790166; bh=xTsiCZc657L7oQhql4ts4mXSow+otBZUp5bcJ6kNE4o=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=Cy8LBVSsmQqXxdWSmyfYBSMocERiuZkmZrhZ3GgNZy/TlkPKDWRhfX0zn20CPDbzI WIdiQKMZ2IJbKgkYBao+D+178EIqJMAcXH6k4PHgvbidXqs5sPk86HP9E3zLzk7MeI nhK7gY6Cy7f1LHeMgsLdRhKzrMNJ4dgbnBPAyUFIdwP+m0ykPCh4QRf2iep9dO/2Lb daapglSqminHk5rg0REH/gcrR82lwucsaJuaw2Ftrc01T6Rpf0ngQovjew6B5K0qXj 8DagkkUoACj6VDRfMd8rjF1NEdMFLIGrt9a5F3W7SWpeTCUpXMq6KnUweXB46R3zST ZhIuJ7FqP+yGg== Date: Fri, 23 Oct 2026 14:16:05 -0700 From: Jakub Kicinski To: =?UTF-8?B?w5ZtZXI=?= Mete Kaya Cc: netdev@vger.kernel.org, oneukum@suse.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net v4] usbnet: fix EVENT_RX_PAUSED race in usbnet_skb_return() Message-ID: <20261023141605.74390430@kernel.org> In-Reply-To: <20261020153044.18828-1-omermetekaya0@gmail.com> References: <20261020153044.18828-1-omermetekaya0@gmail.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Tue, 20 Oct 2026 18:29:09 +0300 =C3=96mer Mete Kaya wrote: > struct sk_buff *skb; > int num =3D 0; > + unsigned long flags; reverse xmas tree ordering please > local_bh_disable(); > + spin_lock_irqsave(&dev->rxq_pause.lock, flags); > clear_bit(EVENT_RX_PAUSED, &dev->flags); > - > - while ((skb =3D skb_dequeue(&dev->rxq_pause)) !=3D NULL) { > + while ((skb =3D __skb_dequeue(&dev->rxq_pause)) !=3D NULL) { > + spin_unlock_irqrestore(&dev->rxq_pause.lock, flags); > usbnet_skb_return(dev, skb); > + spin_lock_irqsave(&dev->rxq_pause.lock, flags); > num++; > } > - > + spin_unlock_irqrestore(&dev->rxq_pause.lock, flags); The retaking of the lock in the loop looks ugly / unnecessary to me struct sk_buff_head q; struct sk_buff *skb; unsigned long flags; int num =3D 0; __skb_queue_head_init(&q); local_bh_disable(); spin_lock_irqsave(&dev->rxq_pause.lock, flags); clear_bit(EVENT_RX_PAUSED, &dev->flags); skb_queue_splice_init(&dev->rxq_pause, &q); spin_unlock_irqrestore(&dev->rxq_pause.lock, flags); while ((skb =3D __skb_dequeue(&q))) { usbnet_skb_return(dev, skb); num++; } --=20 pw-bot: cr