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 929CC7DA8A; Thu, 15 Aug 2024 13:31:47 +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=1723728707; cv=none; b=ZIfvIikKssTa5AIkahRkTtrkM4M/jP/lnrc5kjO0ByOy3Nl0tXADVjSFM1HzhYsDmo0cFMCQHoVsWqxYJzDWtD2kYqbkKvhxwQ0Lq8Cbv08315iQ5M6NCVDTfS5b8yGa0DtSoPEZvQANmWQqKN/GYFn3nqHbKJfSEj3/7BrjEno= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723728707; c=relaxed/simple; bh=WserUgcT2x1XldaT6vEgamkqyAQYbT0lZfFOKdJ5AyU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PqVJFb3ZU/aq2z81mbWx+xEpGZO8UDAYZ0ZaCN+J2wSKFnnIn8JQm8G1/OHPQ1OiJEhDbA6yDKZWhC+3Vd3N7OgtPnu8Zhkn0rIYeaG+KuPdFnZDgnMYdVFJlvSNh35OgS0jR0X06ZhMcAqW4Z/yUtru2ECsJIgf7hFCP21C1vU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=M4jj4+Gr; 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="M4jj4+Gr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 156A9C4AF0C; Thu, 15 Aug 2024 13:31:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1723728707; bh=WserUgcT2x1XldaT6vEgamkqyAQYbT0lZfFOKdJ5AyU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=M4jj4+GrrsF+3S3/neVjdasgHE/BOitT7x965W800xvf9HGT4eFTk/2HiN3DMCo+c HFKPnn3HLvdVJ64OphOLalSBbE10+11tTQwqZrGRMI7mKp/Jq2ES8ZchovRwsF9F7b SrRla920rmwkaBZCw3wwk7wzN6sSGfH3C3V3fXNU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zijun Hu , Lk Sii Subject: [PATCH 4.19 085/196] kobject_uevent: Fix OOB access within zap_modalias_env() Date: Thu, 15 Aug 2024 15:23:22 +0200 Message-ID: <20240815131855.333393132@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240815131852.063866671@linuxfoundation.org> References: <20240815131852.063866671@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 4.19-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 @@ -430,8 +430,23 @@ 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;