* [PATCH] mm/hugetlb: fix early boot crash on parameters without '=' separator
@ 2026-04-09 10:54 Thorsten Blum
2026-04-09 11:03 ` Muchun Song
0 siblings, 1 reply; 2+ messages in thread
From: Thorsten Blum @ 2026-04-09 10:54 UTC (permalink / raw)
To: Muchun Song, Oscar Salvador, David Hildenbrand, Andrew Morton,
Frank van der Linden
Cc: Thorsten Blum, stable, linux-mm, linux-kernel
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.
Fixes: 5b47c02967ab ("mm/hugetlb: convert cmdline parameters from setup to early")
Cc: stable@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
mm/hugetlb.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 327eaa4074d3..9fda39132d26 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4252,6 +4252,9 @@ static __init int hugetlb_add_param(char *s, int (*setup)(char *))
size_t len;
char *p;
+ if (!s)
+ return -EINVAL;
+
if (hugetlb_param_index >= HUGE_MAX_CMDLINE_ARGS)
return -EINVAL;
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] mm/hugetlb: fix early boot crash on parameters without '=' separator
2026-04-09 10:54 [PATCH] mm/hugetlb: fix early boot crash on parameters without '=' separator Thorsten Blum
@ 2026-04-09 11:03 ` Muchun Song
0 siblings, 0 replies; 2+ messages in thread
From: Muchun Song @ 2026-04-09 11:03 UTC (permalink / raw)
To: Thorsten Blum
Cc: Oscar Salvador, David Hildenbrand, Andrew Morton,
Frank van der Linden, stable, linux-mm, linux-kernel
> On Apr 9, 2026, at 18:54, Thorsten Blum <thorsten.blum@linux.dev> wrote:
>
> 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.
>
> Fixes: 5b47c02967ab ("mm/hugetlb: convert cmdline parameters from setup to early")
> Cc: stable@vger.kernel.org
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Thanks.
^ permalink raw reply [flat|nested] 2+ messages in thread
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