From: Thorsten Blum <blum@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>,
Dan Moulding <dmoulding@me.com>
Cc: Thorsten Blum <blum@kernel.org>, linux-kernel@vger.kernel.org
Subject: [PATCH] init: Fix early boot crash with bare hostname parameter
Date: Wed, 26 Aug 2026 12:09:03 +0200 [thread overview]
Message-ID: <20260826100904.296151-2-blum@kernel.org> (raw)
When a bare hostname parameter is specified on the kernel command line
without the '=' separator, early parameter parsing passes NULL to
early_hostname(), which dereferences it in strscpy() and can crash the
system during early boot.
Reject NULL values in early_hostname() and return -EINVAL instead.
Fixes: 5a704629f2c1 ("init: add "hostname" kernel parameter")
Cc: stable@vger.kernel.org
Signed-off-by: Thorsten Blum <blum@kernel.org>
---
init/version.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/init/version.c b/init/version.c
index 94c96f6fbfe6..0bd5c45aabc4 100644
--- a/init/version.c
+++ b/init/version.c
@@ -23,6 +23,9 @@ static int __init early_hostname(char *arg)
size_t maxlen = bufsize - 1;
ssize_t arglen;
+ if (!arg)
+ return -EINVAL;
+
arglen = strscpy(init_uts_ns.name.nodename, arg, bufsize);
if (arglen < 0) {
pr_warn("hostname parameter exceeds %zd characters and will be truncated",
reply other threads:[~2026-08-26 10:09 UTC|newest]
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