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 3700855C1DE for ; Tue, 8 Sep 2026 18:28:49 +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=1788892134; cv=none; b=ZR7RfzE4Vs0mCkjiWFWO0RMkdnPHLKf5MNks2521lZsgfcTpmnTO1cM1XL28vRcJs8Ko+RCX6822inJs8/r7hGlWJDtiEPQxFV4nwcOaBSsUKksiU4tW273tzvBXZnktQlemRXfQsEWWF/VcA938V7zOnFJsMGzASQLFbzEekNg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788892134; c=relaxed/simple; bh=+vSTPfwVCT2X4gzVcq/sbWilrOC6UfZBp1qn6gv3a+w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tJ1S1WnnsjCgT0by3hkUlACPpLOap+6G835CuoeBbWbJSwj2qwpRtCco9ggpOA1WMliVszCUY9FNfCLuidhfchW5wOifV/tw7q08kjm1o+zCmEPyAzuXcxTVXzwSa3YMvEsGHtEBUcj0CvRs/BZhgSjKYNUMuzsJKkI59kzeLew= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=feW4zUjY; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="feW4zUjY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 928FA1F00A3E; Tue, 8 Sep 2026 18:28:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788892128; bh=QWKFYJvaLds18VQbS96gK9KehCcriKIKlhJVj9xk/Tc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=feW4zUjYy7InewlsoFFXD67GNl3cUhFv8yujwDZxu1g8qOjC350gOPXnfksoundyY coohmtzMUfpw4zne5AGBCXSyY/Mici0FSzk77P/sBZ8nKPgMYU8xfbx7x627rgm8at cvs5S83WiHspRdOBVsHwJdXkgdtgeoX1Hrt1wt5mErK3QYOBveCWrEU+eWjJ4Ca4Ts Vgfj/NGpTsqxPsd0dIIq9yRFXAsbffWLErY1ofEz96iL+RKlk+c5JERgKyGMf0hMX5 c5VmeeggEdVOIMmh9ApmGam4/FKIFFTB8xxgJrgOHCAp/PxNfUImDempbHxAbAFl7g IJTBHDEmiczkA== From: Sasha Levin To: stable@vger.kernel.org Cc: Andy Shevchenko , Luis Chamberlain , Kees Cook , Sasha Levin Subject: [PATCH 5.10.y 2/6] params: Do not go over the limit when getting the string length Date: Tue, 8 Sep 2026 14:28:41 -0400 Message-ID: <20260908182845.219246-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260908182845.219246-1-sashal@kernel.org> References: <2026090333-barista-diagnosis-cdab@gregkh> <20260908182845.219246-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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