From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 742201AC8BB; Thu, 15 Aug 2024 14:16:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723731391; cv=none; b=YLnFxusrqgPSg4YUounNH5XFyuFGiss4qBu1Ykr48w4RrvTB/z3B3/glb8enIlr3GG/XkyEjNZICmS7Rb6K50EAb+SQJvKRFE4D1P0806yoMSiaDE+ofG6Bx0NTvobqCP7TLu5KX4+W/AyPljg1HzG2E25+yT6UN1F5wqEaDfyA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723731391; c=relaxed/simple; bh=CPqHFATPY3MLKG7J+fwQD8Z2aHXkT+rNkWkdfiL8m0g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fit7nrce1marDkuJKPtCUZ2dL9IhMLfiCno4yKbZbYZgAgfQ2FTt/yFZ7x3LyQ0wWldSO2twmcyauG9/NuOzFAKAmezmRvD4rgQoNO/A8I+NK0dIAtY3sVEX2hZnbqU8ujYayIVnHxLIXu3Xau7/qqAFom0M1GnWiHjXvlG8nB4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OS6579PZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="OS6579PZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F062CC4AF0C; Thu, 15 Aug 2024 14:16:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1723731391; bh=CPqHFATPY3MLKG7J+fwQD8Z2aHXkT+rNkWkdfiL8m0g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OS6579PZiVXnDRBHYhSEkNCUYT6UdnsN5E76I7udUZ+dHdvUM6EUe2U5mPDLPffgL LIQ/C6h/x2b9LP5GPQ2RpHikQmqYw5xjnXiJrvBXUqbS1BLXRW2wpa1t6I/Lm3RVFg 6RyDx3PbljPTg/5K1MdnicE6e+OwOGB7b9qFzGo4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zijun Hu , Lk Sii Subject: [PATCH 5.4 114/259] kobject_uevent: Fix OOB access within zap_modalias_env() Date: Thu, 15 Aug 2024 15:24:07 +0200 Message-ID: <20240815131907.202503337@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240815131902.779125794@linuxfoundation.org> References: <20240815131902.779125794@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zijun Hu commit dd6e9894b451e7c85cceb8e9dc5432679a70e7dc upstream. zap_modalias_env() wrongly calculates size of memory block to move, so will cause OOB memory access issue if variable MODALIAS is not the last one within its @env parameter, fixed by correcting size to memmove. Fixes: 9b3fa47d4a76 ("kobject: fix suppressing modalias in uevents delivered over netlink") Cc: stable@vger.kernel.org Signed-off-by: Zijun Hu Reviewed-by: Lk Sii Link: https://lore.kernel.org/r/1717074877-11352-1-git-send-email-quic_zijuhu@quicinc.com Signed-off-by: Greg Kroah-Hartman --- lib/kobject_uevent.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -432,8 +432,23 @@ static void zap_modalias_env(struct kobj len = strlen(env->envp[i]) + 1; if (i != env->envp_idx - 1) { + /* @env->envp[] contains pointers to @env->buf[] + * with @env->buflen chars, and we are removing + * variable MODALIAS here pointed by @env->envp[i] + * with length @len as shown below: + * + * 0 @env->buf[] @env->buflen + * --------------------------------------------- + * ^ ^ ^ ^ + * | |-> @len <-| target block | + * @env->envp[0] @env->envp[i] @env->envp[i + 1] + * + * so the "target block" indicated above is moved + * backward by @len, and its right size is + * @env->buflen - (@env->envp[i + 1] - @env->envp[0]). + */ memmove(env->envp[i], env->envp[i + 1], - env->buflen - len); + env->buflen - (env->envp[i + 1] - env->envp[0])); for (j = i; j < env->envp_idx - 1; j++) env->envp[j] = env->envp[j + 1] - len;