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 EAC613403F3; Sat, 30 May 2026 16:51:41 +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=1780159902; cv=none; b=N/GpgcX9747ZQ7ThO39vXEe2G6JLvX5dpcJKrjJyiauUTIH6FE5j4mOJPQ14uAxS1Wao+jLp5dB5hM2W+bWmmIJBnEKIer+BHZwqlvzcUm3WLtkcwIDEF6LivI3UtRPhP/kzsFVYsXVtlUGr+gBehiwZJp5JsaTp2vonLBDycO8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780159902; c=relaxed/simple; bh=Rtkk95fpc8RAWCNL6L3IJWQTgBAD+u4541ZQi4gvd4s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oPRz8Qff1vS+C1Spl+NcraVBiHzWum6u4NerWcKx0EGGuK6o4rS3SVr35cwzvFClV1/uHQvAYDZWVqqwKAMp5T+4PjPo45EomPgKQE6xIHjXwJA7UihHlNqUPAVIX87BuMCfMuW2+dQYLb89Y1uH/MaS2gtkNkESdnB5bLkg/bQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zJNRKGyK; 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="zJNRKGyK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F1E071F00893; Sat, 30 May 2026 16:51:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780159901; bh=pisgsx44NhPwChF5DdasIN+95JiDopbcjzvfrRtr5jI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=zJNRKGyKA6Iyz9xCDQRZY66DQJUiNY5tPN+tbHbNJONqMy5uiDMmls1dCfMELUtXs pT7JrvfnDD72M6oh8kiMAPXJrfgQ0zOapuT9k2KkMyMEt58zRExO2ufnmIYEUC1Awd jvllU7A/irqMvx+UCXNVNm5dHJf6rIraMDV1dDaQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Josh Law , Andrew Morton Subject: [PATCH 6.1 190/969] lib/ts_kmp: fix integer overflow in pattern length calculation Date: Sat, 30 May 2026 17:55:14 +0200 Message-ID: <20260530160305.727108269@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160300.485627683@linuxfoundation.org> References: <20260530160300.485627683@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 6.1-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))