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 EA97C595726 for ; Tue, 8 Sep 2026 17:55:43 +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=1788890145; cv=none; b=acljqO1WAoYqwB4OFa0oB0SW6HcrKeKchYqZYYJPf7qJ5reMv+Xg2TBsARoQvGaw4VMvcjl60B01/VFPBTeoW9eHPblc9SIIg4fEWSxrYTKVOJ55hO97UR2fPOkdzqs89OdxBiQJTHnok229Ng2VPfO/b5U08lAMAQiVqqyDYCI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788890145; c=relaxed/simple; bh=TX8r1tAhGswayWtDEItGnY4qR+NlAOiuzHOvXPD0Das=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Jcp1oo4lkcDPHjsDJi5/o1JEbMBBj0QXTQizXfAHGHgOUwohJJ2FNDVrhTDeqIS2Yf1ib6rf1ZEK5d+iWKcZEsAX6xaz1o5Ml4Ncc03iMpqvoIXOu10wW2RuU33uFtnIIKJPj4reYXrtkdUIM2p4quQciFoTM0l7DAwX3/NoBYY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZWR3xVwM; 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="ZWR3xVwM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34D291F00A3A; Tue, 8 Sep 2026 17:55:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788890143; bh=NJMpvAPB8nGdzAKYCLTzwm0XNo7f7ziTbgnmmuG+lME=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ZWR3xVwMsrSkaTb1wcdaPpSnPqBKae7DtNKcpowrJBsEG377jMhP9p0w3G/z9coUv IxJaVLPH7dtHFa6JP+MWzX4VY95TV4nihU0mTvdoJ543SIsZFHQWhBIIpBYrNmryyx NEDeRtchzhfpTwRHkMYg5Q9NPtPKvCrI7X6s+fwZQ6aoynissR058CMJms3vZ7F9YR GbqzY9fR0STMljXw2UQQ7Hve19EbONkLFl57pam0ZYwsqXaHydGa5S61mg8WY3qq7x jD7Uo7IMI2ruplCqKZOIjwJqNXb9JfkUBzfdd66jK2fMdPvOqtVkFaYh3b/KhHEZVD ACrU/QwyBficg== From: Sasha Levin To: stable@vger.kernel.org Cc: Andy Shevchenko , Luis Chamberlain , Kees Cook , Sasha Levin Subject: [PATCH 6.6.y 1/5] params: Do not go over the limit when getting the string length Date: Tue, 8 Sep 2026 13:55:37 -0400 Message-ID: <20260908175541.151692-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026090331-stays-casually-f049@gregkh> References: <2026090331-stays-casually-f049@gregkh> 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 9d09ea99363fc..8992899996984 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