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 9F27859D612 for ; Tue, 8 Sep 2026 18:15:43 +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=1788891345; cv=none; b=uc+b0qoAErQiixpSosQjbLEBejrVlOsowDlfqwd9OW4fN8qjA3bKb7Ossbr4tZFrUepVnTHx1ulBr1gZriB4sVlBT74kVQJIbcWDeedA5Im2qwsQVVH4+XKCiRpciBto2EZWOXMrtF70oSehCwzCTFIeq2XK/Jz8/mUHJWZeLaU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788891345; c=relaxed/simple; bh=KNE/Hig0bFcNSlGLOokOB4I/Z5pDYVqw2tbsvUQf78o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MvLQ3skmC333s05d15pFPqJhgNGfPesCZwtKKgVAregCTfoMlmu3o3VppPYojFvhZHCEvca9XZ37gGtkZiHqUAdA6UO8/J6Qz05P9Ht1OmqtOsuc1CRh1VOiHvf5G7u6JcpSbKAINUuexg8TDYElqyq21SL3gmS6+ap2Wk1zsjg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BZWBsDuX; 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="BZWBsDuX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 594F11F00A3D; Tue, 8 Sep 2026 18:15:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788891342; bh=DXN5W8aQheicVRMNJpHRfA23QTa84V8MTwkWqsr0r4Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BZWBsDuXFYfVC8GJ2qgLZGIUeXlpRmsDqB5XxysJZe+UDw02xBitCFjQmMw7eMEYx RrNxTVjGRAJU1tcwv5OuhsA0TBOEf/M80W6JWEWyla86Ulr/8Hhb44rmZ0Z/m5Thl0 9viMxt80UHZtiRcqb4dlHDAx5wsTDyJn4JSlyMvIVMbgCBxQwtn2bYfhy+JUW6Jp50 yjRpWlpE0vnie3U2GMPs61CcnrxQWRtQqHLTQTAuJx3OwgL9x2E/chLWgF3tTeKz99 F8YuShwtuE7wDuDrxpNZcI0E1KQomIKO4PN5Y2c3693Ghc8i5m0NDVdPk+ZJb5gInm elhmuFJD2Xj1Q== From: Sasha Levin To: stable@vger.kernel.org Cc: Andy Shevchenko , Luis Chamberlain , Kees Cook , Sasha Levin Subject: [PATCH 6.1.y 2/6] params: Do not go over the limit when getting the string length Date: Tue, 8 Sep 2026 14:15:35 -0400 Message-ID: <20260908181539.191940-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260908181539.191940-1-sashal@kernel.org> References: <2026090332-blazing-handcart-8248@gregkh> <20260908181539.191940-1-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 e6df4c2ef097c..89c139e861faf 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