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Subject[PATCH] mm/large system hash: avoid possible NULL deref in alloc_large_system_hash
Date
From: Eric Dumazet <edumazet@google.com>

If __vmalloc() returned NULL, is_vm_area_hugepages(NULL) will fault
if CONFIG_HAVE_ARCH_HUGE_VMALLOC=y

Fixes: 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
---
mm/page_alloc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b37435c274cf1cb1fabd26465ca7899bb610d91f..e115e21524739341d409b28379942241ed403060 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8756,7 +8756,8 @@ void *__init alloc_large_system_hash(const char *tablename,
} else if (get_order(size) >= MAX_ORDER || hashdist) {
table = __vmalloc(size, gfp_flags);
virt = true;
- huge = is_vm_area_hugepages(table);
+ if (table)
+ huge = is_vm_area_hugepages(table);
} else {
/*
* If bucketsize is not a power-of-two, we may free
--
2.33.0.309.g3052b89438-goog
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