+ init-fix-early-boot-crash-with-bare-hostname-parameter.patch added to mm-nonmm-unstable branch

+ init-fix-early-boot-crash-with-bare-hostname-parameter.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: init: Fix early boot crash with bare hostname parameter
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     init-fix-early-boot-crash-with-bare-hostname-parameter.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/init-fix-early-boot-crash-with-bare-hostname-parameter.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Thorsten Blum <blum@kernel.org>
Subject: init: Fix early boot crash with bare hostname parameter
Date: Wed, 26 Aug 2026 12:09:03 +0200

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.

Link: https://lore.kernel.org/20260826100904.296151-2-blum@kernel.org
Fixes: 5a704629f2c1 ("init: add "hostname" kernel parameter")
Signed-off-by: Thorsten Blum <blum@kernel.org>
Cc: Dan Moulding <dmoulding@me.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 init/version.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/init/version.c~init-fix-early-boot-crash-with-bare-hostname-parameter
+++ a/init/version.c
@@ -23,6 +23,9 @@ static int __init early_hostname(char *a
 	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",
_

Patches currently in -mm which might be from blum@kernel.org are

maintainers-mailmap-update-entries-for-thorsten-blum.patch
init-fix-early-boot-crash-with-bare-hostname-parameter.patch