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 F248A5372EA; Wed, 23 Sep 2026 14:47:46 +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=1790174868; cv=none; b=t7/Q5saqn7Uf4MehSU5kL1CfZPBxRy8gHjojP909TocMnzUyi5CO3x/WdClLvF7Eb0LGHNJViEipyjeSFvNLlhxOMsu/tOk89xgRZMfsggJklA5zJQyx1IchKxja8Hcr+pjN9xHuNt1mIG/XZpkXFGgP6/jUmouPxv17u9Mpw6g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790174868; c=relaxed/simple; bh=c4cvAz9q2G6xQ4X1Ml8K9zRa96r8lewFh7BmGhJKpJ4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=H2xbESTnyD54wpoAd1e2uKW91QO40PpTglUEHY8RlsuPJzvgwGiXjSFrzgbL2HJDVf0quDRmwkXf4LP2cX9AEM6bjLoB5vIJj+qNtbtfkEsH290yHYLXEisiGS93qelMn2Kis55sc5Uc6V53DfDEZ7ELeMQt9l2mT0u7jErEsnU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WewmBs1/; 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="WewmBs1/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 563161F00898; Wed, 23 Sep 2026 14:47:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790174866; bh=sksZJPjaeELsQ5KY/S4X4EEQ1s17uz+SPpkjruU3W2w=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=WewmBs1/Zut1MLP2yjXZPYa8NMVANTV9OvFoSmcTsPK0EvBRbIuWUZMW37vKPWkFY u+6y5CYIrxpaUAyRw23lvA8gQnOdHsmxdD8G6NkceXsyubw3DMgCrD5MCIz2JXv0K1 YQeYPZRSvJW3fdMCppegV8/u4yHJPuBBh45hnvxY= 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 6.18 252/398] net/packet: avoid truncating TPACKET_V3 private size Date: Wed, 23 Sep 2026 16:05:26 +0200 Message-ID: <20260923140649.943793776@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140643.441954610@linuxfoundation.org> References: <20260923140643.441954610@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 6.18-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 int hdrlen; unsigned char reset_pending_on_curr_blk; unsigned short kactive_blk_num; - unsigned short blk_sizeof_priv; + unsigned int blk_sizeof_priv; unsigned short version;