+ mm-hugetlb-fix-early-boot-crash-on-parameters-without-=-separator.patch added to mm-unstable branch

+ mm-hugetlb-fix-early-boot-crash-on-parameters-without-=-separator.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/hugetlb: fix early boot crash on parameters without '=' separator
has been added to the -mm mm-unstable branch.  Its filename is
     mm-hugetlb-fix-early-boot-crash-on-parameters-without-=-separator.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-fix-early-boot-crash-on-parameters-without-=-separator.patch

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

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------------------------------------------------------
From: Thorsten Blum <thorsten.blum@linux.dev>
Subject: mm/hugetlb: fix early boot crash on parameters without '=' separator
Date: Thu, 9 Apr 2026 12:54:40 +0200

If hugepages, hugepagesz, or default_hugepagesz are specified on the
kernel command line without the '=' separator, early parameter parsing
passes NULL to hugetlb_add_param(), which dereferences it in strlen() and
can crash the system during early boot.

Reject NULL values in hugetlb_add_param() and return -EINVAL instead.

Link: https://lkml.kernel.org/r/20260409105437.108686-4-thorsten.blum@linux.dev
Fixes: 5b47c02967ab ("mm/hugetlb: convert cmdline parameters from setup to early")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Frank van der Linden <fvdl@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/hugetlb.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/mm/hugetlb.c~mm-hugetlb-fix-early-boot-crash-on-parameters-without-=-separator
+++ a/mm/hugetlb.c
@@ -4226,6 +4226,9 @@ static __init int hugetlb_add_param(char
 	size_t len;
 	char *p;
 
+	if (!s)
+		return -EINVAL;
+
 	if (hugetlb_param_index >= HUGE_MAX_CMDLINE_ARGS)
 		return -EINVAL;
 
_

Patches currently in -mm which might be from thorsten.blum@linux.dev are

mm-hugetlb-fix-early-boot-crash-on-parameters-without-=-separator.patch