The patch titled Subject: mm/memory_hotplug: fix error handling in add_memory_resource() has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-memory_hotplug-fix-error-handling-in-add_memory_resource.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memory_hotplug-fix-error-handling-in-add_memory_resource.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Sumanth Korikkar <sumanthk@xxxxxxxxxxxxx> Subject: mm/memory_hotplug: fix error handling in add_memory_resource() Date: Mon, 20 Nov 2023 15:53:53 +0100 In add_memory_resource(), creation of memory block devices occurs after successful call to arch_add_memory(). However, creation of memory block devices could fail. In that case, arch_remove_memory() is called to perform necessary cleanup. Currently with or without altmap support, arch_remove_memory() is always passed with altmap set to NULL during error handling. This leads to freeing of struct pages using free_pages(), eventhough the allocation might have been performed with altmap support via altmap_alloc_block_buf(). Fix the error handling by passing altmap in arch_remove_memory(). This ensures the following: * When altmap is disabled, deallocation of the struct pages array occurs via free_pages(). * When altmap is enabled, deallocation occurs via vmem_altmap_free(). Link: https://lkml.kernel.org/r/20231120145354.308999-3-sumanthk@xxxxxxxxxxxxx Fixes: a08a2ae34613 ("mm,memory_hotplug: allocate memmap from the added memory range") Signed-off-by: Sumanth Korikkar <sumanthk@xxxxxxxxxxxxx> Reviewed-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx> Acked-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx> Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx> Cc: Heiko Carstens <hca@xxxxxxxxxxxxx> Cc: kernel test robot <lkp@xxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [5.15+] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory_hotplug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/memory_hotplug.c~mm-memory_hotplug-fix-error-handling-in-add_memory_resource +++ a/mm/memory_hotplug.c @@ -1458,7 +1458,7 @@ int __ref add_memory_resource(int nid, s /* create memory block devices after memory was added */ ret = create_memory_block_devices(start, size, params.altmap, group); if (ret) { - arch_remove_memory(start, size, NULL); + arch_remove_memory(start, size, params.altmap); goto error_free; } _ Patches currently in -mm which might be from sumanthk@xxxxxxxxxxxxx are mm-memory_hotplug-add-missing-mem_hotplug_lock.patch mm-memory_hotplug-fix-error-handling-in-add_memory_resource.patch mm-use-vmem_altmap-code-without-config_zone_device.patch