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 189CC3C455B; Sat, 30 May 2026 18:28:21 +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=1780165702; cv=none; b=ZM7RGpiK/CV416pIOvGIjE0T/bu2sWW/hcIMQP8KA60ck/O4Yzof8dFnHIk9+kMbk/lL3X7XrX8aMzTwtVopg9ov9o/zyd3VjlSPlcTXG9w9qKf1nF2+jgb9xwI/ciQ4gk4J54U8yDHObgVWZRnB0TwSNDzCL9o2DDfRVXcgLj0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780165702; c=relaxed/simple; bh=WlvssRbRH7XABY/AFYLG2dqIzvbpukSvnEv/Xi7RYro=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LM1jt3iedfiDK8grI9l13zQW0VVtPnWYWKabQ9qmjVXF6F63CAFjmDGvDBqASsgIWjh/+T/8PgvGhyMdGNawcluOSkj5rFduyadeJvLlGohOaOAyDbf5utSluVzP221ipSkUlhw6Q3f0RB9aXgJcBTT4SroouHrj4YYSANOF55I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mJC0OeiT; 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="mJC0OeiT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 573B51F00899; Sat, 30 May 2026 18:28:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780165701; bh=mWO9wYpzDsYxzUR3lGLp2BkKTvttqtSi7m3tV0w2ZYw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=mJC0OeiTxuGQSZr0TV0SVxzevPFqmz9i6IQ1qJjgd1tSI+XllMx82TKNApkEAau/8 kAqpHMAvv+9nWuLZzMxqSeInO6UtyaB6IHi6Oww1kgm1jIu896oSvC+HXPclXk9S2Y DOU4/rUcuyP/JmB0POGodEFdX2QeO83vM5njLhlM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Josh Law , Andrew Morton Subject: [PATCH 5.10 156/589] lib/ts_kmp: fix integer overflow in pattern length calculation Date: Sat, 30 May 2026 18:00:37 +0200 Message-ID: <20260530160228.886204977@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160224.570625122@linuxfoundation.org> References: <20260530160224.570625122@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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josh Law commit 8cdf30813ea8ce881cecc08664144416dbdb3e16 upstream. The ts_kmp algorithm stores its prefix_tbl[] table and pattern in a single allocation sized from the pattern length. If the prefix_tbl[] size calculation wraps, the resulting allocation can be too small and subsequent pattern copies can overflow it. Fix this by rejecting zero-length patterns and by using overflow helpers before calculating the combined allocation size. This fixes a potential heap overflow. The pattern length calculation can wrap during a size_t addition, leading to an undersized allocation. Because the textsearch library is reachable from userspace via Netfilter's xt_string module, this is a security risk that should be backported to LTS kernels. Link: https://lkml.kernel.org/r/20260308202028.2889285-2-objecting@objecting.org Signed-off-by: Josh Law Reviewed-by: Andrew Morton Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- lib/ts_kmp.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) --- a/lib/ts_kmp.c +++ b/lib/ts_kmp.c @@ -94,8 +94,22 @@ static struct ts_config *kmp_init(const struct ts_config *conf; struct ts_kmp *kmp; int i; - unsigned int prefix_tbl_len = len * sizeof(unsigned int); - size_t priv_size = sizeof(*kmp) + len + prefix_tbl_len; + unsigned int prefix_tbl_len; + size_t priv_size; + + /* Zero-length patterns would make kmp_find() read beyond kmp->pattern. */ + if (unlikely(!len)) + return ERR_PTR(-EINVAL); + + /* + * kmp->pattern is stored immediately after the prefix_tbl[] table. + * Reject lengths that would wrap while sizing either region. + */ + if (unlikely(check_mul_overflow(len, sizeof(*kmp->prefix_tbl), + &prefix_tbl_len) || + check_add_overflow(sizeof(*kmp), (size_t)len, &priv_size) || + check_add_overflow(priv_size, prefix_tbl_len, &priv_size))) + return ERR_PTR(-EINVAL); conf = alloc_ts_config(priv_size, gfp_mask); if (IS_ERR(conf))