The linux-next commit "mm/sparsemem: Add helpers track active portions of a section at boot" [1] causes a crash below when the first kmemleak scan kthread kicks in. This is because kmemleak_scan() calls pfn_to_online_page(() which calls pfn_valid_within() instead of pfn_valid() on x86 due to CONFIG_HOLES_IN_ZONE=n. The commit [1] did add an additional check of pfn_section_valid() in pfn_valid(), but forgot to add it in the above code path. page:ffffea0002748000 is uninitialized and poisoned raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p)) ------------[ cut here ]------------ kernel BUG at include/linux/mm.h:1084! invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI CPU: 5 PID: 332 Comm: kmemleak Not tainted 5.2.0-rc4-next-20190612+ #6 Hardware name: Lenovo ThinkSystem SR530 -[7X07RCZ000]-/-[7X07RCZ000]-, BIOS -[TEE113T-1.00]- 07/07/2017 RIP: 0010:kmemleak_scan+0x6df/0xad0 Call Trace: kmemleak_scan_thread+0x9f/0xc7 kthread+0x1d2/0x1f0 ret_from_fork+0x35/0x4 [1] https://patchwork.kernel.org/patch/10977957/ Signed-off-by: Qian Cai <cai@xxxxxx> --- include/linux/memory_hotplug.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 0b8a5e5ef2da..f02be86077e3 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -28,6 +28,7 @@ unsigned long ___nr = pfn_to_section_nr(___pfn); \ \ if (___nr < NR_MEM_SECTIONS && online_section_nr(___nr) && \ + pfn_section_valid(__nr_to_section(___nr), pfn) && \ pfn_valid_within(___pfn)) \ ___page = pfn_to_page(___pfn); \ ___page; \ -- 1.8.3.1
