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 6ACB33DD849; Wed, 30 Sep 2026 19:25:01 +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=1790796302; cv=none; b=soKv4SkkYiZgAd1wLbl7nmM9HBWnFbhSImd/p3HztWQFTShvP9kAm+w4XD9d55sqYt5/+6HKtnP7rJvnwftitq3CwegZ8Ygi56KafB0tkKcQgAXgrYtO4uyfncD1BkYEU22PYgBWPmcvqqJ9ZfKMtAsOJ17oJ14EAU46ZU1N68o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790796302; c=relaxed/simple; bh=4wIHSIvScGbv/gYpmDQxuVOF4L08AGm5v79YTk4dSNU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jlXhg8gdQbZAm4QIQ2L/DAh4g/0j7iKB6p9rCPBvnuQvtJfH5tjFiKTAmzp1eUrsJzUJJV7KpLNiPVq+XOwydYcVc7koTAS+gezS3N7hnWO0VF4n+98DAWi3y7pW+pCs5tBhEKlK1e/jRYpBkQfILUPWq1gjo5NY88uKgGafUv0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ebNbbtKk; 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="ebNbbtKk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3CCF1F000FF; Wed, 30 Sep 2026 19:25:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790796301; bh=DkO86MPbo3ufOmtL09y/+OF9eKucYDUhvUBkBJqVkJ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ebNbbtKk96Njf3vGKGd6I0adY5EIWqBzHVZQsBwWXDVOUzI1B4D0yuR0yTIRf02jj I+5AYZnVRiY7ijwmwAADkYjnyzwd46CcUfaFHNlSBt+zG92U7SUpiHrmuy18/yVYw8 r6un+8JBgjDn0yYIS8AWvwzy8eVXUqmKimejPNj0= 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 6.6 0866/1193] net/packet: avoid truncating TPACKET_V3 private size Date: Wed, 30 Sep 2026 17:25:50 +0200 Message-ID: <20260930152453.476122506@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152434.301151190@linuxfoundation.org> References: <20260930152434.301151190@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 6.6-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