From ec05f51f1e65bce95528543eb73fda56fd201d94 Mon Sep 17 00:00:00 2001 From: "Uladzislau Rezki (Sony)" Date: Mon, 13 Apr 2026 21:26:46 +0200 Subject: [PATCH] mm/vmalloc: take vmap_purge_lock in shrinker decay_va_pool_node() can be invoked concurrently from two paths: __purge_vmap_area_lazy() when pools are being purged, and the shrinker via vmap_node_shrink_scan(). However, decay_va_pool_node() is not safe to run concurrently, and the shrinker path currently lacks serialization, leading to races and possible leaks. Protect decay_va_pool_node() by taking vmap_purge_lock in the shrinker path to ensure serialization with purge users. Link: https://lore.kernel.org/20260413192646.14683-1-urezki@gmail.com Fixes: 7679ba6b36db ("mm: vmalloc: add a shrinker to drain vmap pools") Signed-off-by: Uladzislau Rezki (Sony) Reviewed-by: Baoquan He Cc: chenyichong Cc: Signed-off-by: Andrew Morton --- mm/vmalloc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 61caa55a4402..676851d5cfe7 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -5416,6 +5416,7 @@ vmap_node_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) { struct vmap_node *vn; + guard(mutex)(&vmap_purge_lock); for_each_vmap_node(vn) decay_va_pool_node(vn, true);