From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 ACDDB516168; Wed, 30 Sep 2026 18:15:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792110; cv=none; b=LMuR+11YtukswhvrK75zELbEWb9yGrMzJng4CV4gdkP7v5WgfYvbhuvkO2QoKlVjdnhw/AwUN6vxlamjHvlosYi9h2r868cMP8VvtmDaYTh+Rl85YFm0one4yLGZHZtp0H6KoisTNI2YfnZkpIDWVC44YG1zZIB9Bu3q1Af9ce8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792110; c=relaxed/simple; bh=fSv0ZCQMItOcP1Klye7OIa0nU1i1TjMdz2Z4C5Em8cw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fMNq0RViZbkEvch9aBLmY/TeyEkhpYhjmps3GRAtA9zFYe0YLpQK00r3/9D2KSFbraGaDVRopjPX6AkNHfX+cRrAR80n+28WOvqy/WmuGfN1pZY2yMshCn97or7ovEAB9ymw51x/YfgqX/odqGqFBoCcP9YrPzvmwuThElQgtPk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TmxbC7rp; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="TmxbC7rp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 112FD1F000FF; Wed, 30 Sep 2026 18:15:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790792109; bh=i9cssXhBBdPnfwPXJCKdZ3JWC1fLVrpda09Fwo24Fmg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TmxbC7rpAm6UtMbcg6V9Y9LSQh8ftsvaK7Gnit5AGlv5p9AxIgPGfL6Id351qsUS3 5bZQLksrER9YBbGn3UwQkPutGRDpuXFdFGPSiYu39mhvBpLWYknHHApMi7Vre5YIqy WGk/uhbhafI4TvXXxfqEkhJxR7kGG4yZlCUmI8jQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mark Amirkan , Willem de Bruijn , Jakub Kicinski Subject: [PATCH 5.15 538/752] net/packet: avoid truncating TPACKET_V3 private size Date: Wed, 30 Sep 2026 17:26:48 +0200 Message-ID: <20260930152409.889069553@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152358.131179731@linuxfoundation.org> References: <20260930152358.131179731@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Amirkan commit 37213e61120297920ae4c937fcb326a360da5084 upstream. tpacket_req3.tp_sizeof_priv is an unsigned int, and packet_set_ring() validates the full value against the block size. init_prb_bdqc() then stores it in the unsigned short blk_sizeof_priv field. Commit 2b6867c2ce76 ("net/packet: fix overflow in check for priv area size") fixed the validation arithmetic, but an accepted value above USHRT_MAX still narrows when it is stored. For a 131072-byte block, tp_sizeof_priv=65536 is valid. The narrowing makes offset_to_first_pkt 48 instead of 65584, so packet records can be placed in the private area that userspace asked the kernel to preserve. blk_sizeof_priv is internal state, so widen it to hold the validated UAPI value. Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.") Cc: stable@vger.kernel.org Signed-off-by: Mark Amirkan Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260913-b4-send-packet-private-v1-1-925eab2cd388@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/packet/internal.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/packet/internal.h +++ b/net/packet/internal.h @@ -21,7 +21,7 @@ struct tpacket_kbdq_core { unsigned char reset_pending_on_curr_blk; unsigned char delete_blk_timer; unsigned short kactive_blk_num; - unsigned short blk_sizeof_priv; + unsigned int blk_sizeof_priv; /* last_kactive_blk_num: * trick to see if user-space has caught up