From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-171.mta0.migadu.com (out-171.mta0.migadu.com [91.218.175.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 720A33DD536 for ; Fri, 3 Jul 2026 12:32:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783081979; cv=none; b=od3J9swsFc4wEgOs4iLnlavY9JA/OU4ENg3mVU0xT3tcahknkln/ljsjSylDS1uQlD3HCqdw/P2ed89S+xVO7eS1OjglU6VvlB1pu59DDuE/jOnHoBOL/z4C5iqmQY45gRsLF5QAo08sMy+u3GgrsEoy1JDi5ryEN7XtZJOeIoo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783081979; c=relaxed/simple; bh=nmZA6+uB3urD2hKCpKw8hiD4oFjQ9dwF7f3r4Tfky8g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hIt+6vncFDo4BSDrO7SBgxxVHNu52mcfAZGxhfIb/5TxO+a64rZxcCqQuacVnnZ8m7gU+wAyIfJP2CiKke8AYCsXPhoakb6ZUD19tPJHdVC7UHwJo+Q53Cx0GG2LL+Cx7VIJ8U/zoqhtkgx+D7OJiMSQ67G65+CabOYAd7+v7V8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=lGEn1QW0; arc=none smtp.client-ip=91.218.175.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="lGEn1QW0" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1783081964; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KPobOMpzLXIZ6h+MVV8WTmoa13pxNOpbezeoUAZoB28=; b=lGEn1QW0L8yjWbmvygdeC/+JFPmdBuDOtLNHL0GwaV3OabcFTtTB7N57JCebnvsxY5f11U JxPftL4Si3/LLOk4OVjNnBewAIQz2oL3dsHYRBTXUfkxsTC1OhC05Y7sLk10yR3fUokWTH pa9kLdLXv25oUUqe2O91ufSHmFeBjV8= From: Usama Arif To: Greg Kroah-Hartman Cc: Usama Arif , stable@vger.kernel.org, patches@lists.linux.dev, Jens Axboe Subject: Re: [PATCH 6.18 044/108] block: invalidate cached plug timestamp after task switch Date: Fri, 3 Jul 2026 05:32:35 -0700 Message-ID: <20260703123236.3139759-1-usama.arif@linux.dev> In-Reply-To: <20260702155113.020016705@linuxfoundation.org> References: Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On Thu, 2 Jul 2026 18:20:41 +0200 Greg Kroah-Hartman wrote: > 6.18-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Usama Arif > > commit fad156c2af227f42ca796cbb20ddc354a6dd9932 upstream. > > blk_time_get_ns() caches ktime_get_ns() in current->plug->cur_ktime > and marks the task with PF_BLOCK_TS. That cache is only valid while the > task keeps running; if the task is switched out, wall-clock time > advances and the cached value must not be reused when the task runs again. > Hi Greg, It looks like this patch was backported, but the preceding patch [1] in the series was not bacported to the stable branches. Both this and its prerequisite have the same Fixes tag. Not having the prerequisite will result in a NULL derefernce. Could we please add [1] to the stable branches? Thanks! [1] https://lore.kernel.org/all/20260616141604.328820-2-usama.arif@linux.dev/