From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E57C04A1E; Mon, 6 Oct 2025 19:23:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759778630; cv=none; b=Nu47EWogKqryLUfENxw/MFHuFq83wajp9nDkb5t19cVFcKiXfT9+VSTGbYYJsxBxDoJBiIWTQPJjZkzVUETs0Mp6CPF0R1OvjdlaJOOr+yOQYK9pIN+lis9pYGJ54c8nLoHOiFyM7L35OyR+LzWD0DlhPrcPPci2NoK7lv7ZWiU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759778630; c=relaxed/simple; bh=3IRDYsJ/lyS6bBFNqgWZ/wSYHq2uNlr+cfD7SYriQkM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hZNo8K+HPZ+Ujp7EPK/L392jqAviNRlEK7DZy7AKUfmHNHFqIkWR3u4k6KchlB3plRGVWFB/cwhTTcW940ilM+eJ9YyDgvF2ruGeihN8nKeWIl7hTf2hEGIxlomPq/GJn79dbYr7CtNVGMvcCQTlGon/XFZDsfLMlNz7ZV/iaXk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iphYsLly; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iphYsLly" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E8D7C4CEF5; Mon, 6 Oct 2025 19:23:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1759778629; bh=3IRDYsJ/lyS6bBFNqgWZ/wSYHq2uNlr+cfD7SYriQkM=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=iphYsLly7QOqRuXXuGM8uHEbpe3bk7vNgjXo6lIwvHbnrM0fSWm3wDMKK1mDPvnJ3 +vW/fDE+MysEziEbbUz4Clg/7DrZ+cYebLr/o3IphZHOuZi4wdDh0I1Lyw6SnQZZdd fhCZiPEs+rz9Mb8mgFYIviTNpDw7ET+Au4b6da1Kv6lObNQxnWoEV4UwQzJ3s3IbC/ 9GkjB3ttQSA+dzscD6SsORAfH6R1wS32apbx9EiLc9QaAh8Ur8o0AMgcfoLykC7/c3 bA6F39zCqG4btRA7Hj6enc1W5QdIoTggoXMq0cvV3HYm/fi2pf/d4/GPP95NpJ1Te0 AWptrSRpg4SsA== Message-ID: <03cb97b4-c58a-42fc-aaea-db63c1b2ce4b@kernel.org> Date: Mon, 6 Oct 2025 13:23:48 -0600 Precedence: bulk X-Mailing-List: linux-kernel-mentees@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] scsi: fix shift out-of-bounds in sg_build_indirect The num variable is set to 0. The variable num gets its value from scatter_elem_sz. However the minimum value of scatter_elem_sz is PAGE_SHIFT. So setting num to PAGE_SIZE when num < PAGE_SIZE. To: Kshitij Paranjape , "Martin K . Petersen" Cc: Doug Gilbert , "James E . J . Bottomley" , skhan@linuxfoundation.org, david.hunter.linux@gmail.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linux.dev, stable@vger.kernel.org, syzbot+270f1c719ee7baab9941@syzkaller.appspotmail.com References: <20251006174658.217497-1-kshitijvparanjape@gmail.com> Content-Language: en-US From: Khalid Aziz In-Reply-To: <20251006174658.217497-1-kshitijvparanjape@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/6/25 11:46 AM, Kshitij Paranjape wrote: > Cc: > Reported-by: syzbot+270f1c719ee7baab9941@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=270f1c719ee7baab9941 > Signed-off-by: Kshitij Paranjape > --- > drivers/scsi/sg.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c > index effb7e768165..9ae41bb256d7 100644 > --- a/drivers/scsi/sg.c > +++ b/drivers/scsi/sg.c > @@ -1888,6 +1888,7 @@ sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size) > if (num < PAGE_SIZE) { > scatter_elem_sz = PAGE_SIZE; > scatter_elem_sz_prev = PAGE_SIZE; > + num = scatter_elem_sz; > } else > scatter_elem_sz_prev = num; > } Please add a one line summary above your commit log to avoid the issue Vivek pointed out. One line summary will become the subject line for your patch email. -- Khalid