From 059ac6252a63edf1cea79bf30bd860a8c264b62c Mon Sep 17 00:00:00 2001 From: Georgi Djakov Date: Thu, 14 May 2026 02:26:57 -0700 Subject: [PATCH] drivers/base/memory: set mem->altmap after successful device registration commit a2b8d7827f48ee54a686cb80e4a1d0ff954ec42a upstream. If __add_memory_block() fails at xa_store() (under memory pressure for example), device_unregister() is called, which eventually triggers memory_block_release() with mem->altmap still set, causing a WARN_ON(mem->altmap). This was triggered by modifying virtio-mem driver. Fix this by delaying the assignment of mem->altmap until after __add_memory_block() has succeeded. Link: https://lore.kernel.org/20260514092657.3057141-1-georgi.djakov@oss.qualcomm.com Fixes: 1a8c64e11043 ("mm/memory_hotplug: embed vmem_altmap details in memory block") Signed-off-by: Georgi Djakov Acked-by: Oscar Salvador (SUSE) Cc: Vishal Verma Cc: Mike Rapoport Cc: Richard Cheng Cc: David Hildenbrand Cc: Georgi Djakov Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/base/memory.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 6981b55d582a..843f85d3e3f9 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -807,7 +807,6 @@ static int add_memory_block(unsigned long block_id, int nid, unsigned long state mem->start_section_nr = block_id * sections_per_block; mem->state = state; mem->nid = nid; - mem->altmap = altmap; INIT_LIST_HEAD(&mem->group_next); #ifndef CONFIG_NUMA @@ -825,6 +824,8 @@ static int add_memory_block(unsigned long block_id, int nid, unsigned long state if (ret) return ret; + mem->altmap = altmap; + if (group) { mem->group = group; list_add(&mem->group_next, &group->memory_blocks);