From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793208375; b=JqRzHOGr90jtoy6T33IzBC7+/0DTeXOTuQTEJ558U/o0dvEo2z8LkXohKPYgpk06UHKt OZPK/ojdsR6E6J8ZoZz+x8Z21sPFizDvWMU6TKTAPENEYZ+UxVEg/nMBYIuFo9H9Rcoa1 zEb+L2aHPk5Dpec6a6/Y6X9yu8+dOVjr3ej1uZv4nZUoxoUgEsuQbQMiSOho+CftRKbSi jTlxizI0SESQZfyoFMFkdjHhzkdcDBctAIUsUqSfA2lv7v2Ueaxsd/amAukG1mc6mJGwT MryYuHz8o/5cwSw+1hseOSNfBImEkmA0QKzM2Ul1uJt+a0YRK2kfnbt4kk//vwg3vsg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793208375; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=SinG8I+vpGmNMl2Dex9h/PrUmZPZWmsyP2RX0914pVg=; b=R5gujFOy81cb7aA1iO8c2hgCQdrEKc0jCghAYR/lN0jM4dU+wt7l/fvSXlPAgRrv+Ppl S9B37xAU9nia4iGbcDqKM2x1jkmQ38tuvBJrvNGnl3hAKsi86ZxPyDSCBaByAReIPAMQG JaYANFYUIYM55zUfu4m9YICK7kqKN0wWqiQcXstum/A0Tfhs7CO1DPU7kJIcTuRh1+m+S vQte2h6l+rbI9fHXuCIyAlsfIzgOFUj8Jr+U3Gx1v5NPbT3F+97yvn61b8f0UGOipK8+G lvAdM0cgt8QY83lAc77iN92Pdgh1GqnEsiM95IjexqMLIk7ERb50fr7I1B/WGUCTfAA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="m/VGLvX6"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E42F7606A31A; Wed, 28 Oct 2026 17:26:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=m/VGLvX6 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 113A41F01828; Wed, 28 Oct 2026 17:26:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793208374; bh=SinG8I+vpGmNMl2Dex9h/PrUmZPZWmsyP2RX0914pVg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=m/VGLvX6lfXURNtbli8HhWwcHOczavDZD297wzvwWZXtB2FNQ0aE4Q++1tbpC28Vj 5ahXHO/KQDV6Ns+FmPyX4ugsQ0U6TzrhA8dJDmhjv7wIbLViXrhSh99G3fliJzr2Gr tzcu3A1QZnBix4aNqMEaXJCPfXaiqu4nErXVAJyM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Luis Chamberlain , Kees Cook , Andy Shevchenko , Sasha Levin Subject: [PATCH 5.10 054/516] params: Do not go over the limit when getting the string length Date: Wed, 28 Oct 2026 17:53:26 +0100 Message-ID: <20261028170004.810652083@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170003.522232767@linuxfoundation.org> References: <20261028170003.522232767@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Shevchenko [ Upstream commit fd0cd057a1b7351604daa6ffc91dfe28adf7225d ] We can use strnlen() even on early stages and it prevents from going over the string boundaries in case it's already too long. Reviewed-by: Luis Chamberlain Reviewed-by: Kees Cook Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20231120151419.1661807-3-andriy.shevchenko@linux.intel.com Signed-off-by: Kees Cook Stable-dep-of: 3dfaae04243c ("params: fix charp corruption on allocation failure") Signed-off-by: Sasha Levin --- kernel/params.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/params.c b/kernel/params.c index 9f0f059571a0a..30c0a7388024e 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -264,7 +264,10 @@ EXPORT_SYMBOL_GPL(param_set_uint_minmax); int param_set_charp(const char *val, const struct kernel_param *kp) { - if (strlen(val) > 1024) { + size_t len, maxlen = 1024; + + len = strnlen(val, maxlen + 1); + if (len == maxlen + 1) { pr_err("%s: string parameter too long\n", kp->name); return -ENOSPC; } @@ -274,7 +277,7 @@ int param_set_charp(const char *val, const struct kernel_param *kp) /* This is a hack. We can't kmalloc in early boot, and we * don't need to; this mangled commandline is preserved. */ if (slab_is_available()) { - *(char **)kp->arg = kmalloc_parameter(strlen(val)+1); + *(char **)kp->arg = kmalloc_parameter(len + 1); if (!*(char **)kp->arg) return -ENOMEM; strcpy(*(char **)kp->arg, val); @@ -512,7 +515,7 @@ int param_set_copystring(const char *val, const struct kernel_param *kp) { const struct kparam_string *kps = kp->str; - if (strlen(val)+1 > kps->maxlen) { + if (strnlen(val, kps->maxlen) == kps->maxlen) { pr_err("%s: string doesn't fit in %u chars.\n", kp->name, kps->maxlen-1); return -ENOSPC; -- 2.53.0