diff mbox series

[v2] mm: fix a possible null pointer dereference in setup_zone_pageset()

Message ID 20241107124116.579108-1-chenqiuji666@gmail.com (mailing list archive)
State New
Headers show
Series [v2] mm: fix a possible null pointer dereference in setup_zone_pageset() | expand

Commit Message

Qiu-ji Chen Nov. 7, 2024, 12:41 p.m. UTC 
The function call alloc_percpu() returns a pointer to the memory address,
but it hasn't been checked. Our static analysis tool indicates that null
pointer dereference may exist in pointer zone->per_cpu_pageset. It is
always safe to judge the null pointer before use.

Signed-off-by: Qiu-ji Chen <chenqiuji666@gmail.com>
Cc: stable@vger.kernel.org
Fixes: 9420f89db2dd ("mm: move most of core MM initialization to mm/mm_init.c")
---
V2:
Fixed the incorrect code logic.
Thanks David Hildenbrand for helpful suggestion.
---
 mm/page_alloc.c | 6 ++++++
 1 file changed, 6 insertions(+)
diff mbox series

Patch

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8afab64814dc..7c8a74fd02d6 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5703,8 +5703,14 @@  void __meminit setup_zone_pageset(struct zone *zone)
 	/* Size may be 0 on !SMP && !NUMA */
 	if (sizeof(struct per_cpu_zonestat) > 0)
 		zone->per_cpu_zonestats = alloc_percpu(struct per_cpu_zonestat);
+	if (!zone->per_cpu_zonestats)
+		return;
 
 	zone->per_cpu_pageset = alloc_percpu(struct per_cpu_pages);
+	if (!zone->per_cpu_pageset) {
+		free_percpu(zone->per_cpu_zonestats);
+		return;
+	}
 	for_each_possible_cpu(cpu) {
 		struct per_cpu_pages *pcp;
 		struct per_cpu_zonestat *pzstats;