From 7bc35fdde6724549a0239b71e08b9f33d8bf2bfb Mon Sep 17 00:00:00 2001 From: Tang Chen Date: Thu, 6 Feb 2014 12:04:27 -0800 Subject: arch/x86/mm/numa.c: fix array index overflow when synchronizing nid to memblock.reserved. The following path will cause array out of bound. memblock_add_region() will always set nid in memblock.reserved to MAX_NUMNODES. In numa_register_memblks(), after we set all nid to correct valus in memblock.reserved, we called setup_node_data(), and used memblock_alloc_nid() to allocate memory, with nid set to MAX_NUMNODES. The nodemask_t type can be seen as a bit array. And the index is 0 ~ MAX_NUMNODES-1. After that, when we call node_set() in numa_clear_kernel_node_hotplug(), the nodemask_t got an index of value MAX_NUMNODES, which is out of [0 ~ MAX_NUMNODES-1]. See below: numa_init() |---> numa_register_memblks() | |---> memblock_set_node(memory) set correct nid in memblock.memory | |---> memblock_set_node(reserved) set correct nid in memblock.reserved | |...... | |---> setup_node_data() | |---> memblock_alloc_nid() here, nid is set to MAX_NUMNODES (1024) |...... |---> numa_clear_kernel_node_hotplug() |---> node_set() here, we have an index 1024, and overflowed This patch moves nid setting to numa_clear_kernel_node_hotplug() to fix this problem. Reported-by: Dave Jones Signed-off-by: Tang Chen Tested-by: Gu Zheng Reported-by: Dave Jones Cc: David Rientjes Tested-by: Dave Jones Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/mm/numa.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c index 45ec9d72b6dd..27aa0455fab3 100644 --- a/arch/x86/mm/numa.c +++ b/arch/x86/mm/numa.c @@ -493,14 +493,6 @@ static int __init numa_register_memblks(struct numa_meminfo *mi) struct numa_memblk *mb = &mi->blk[i]; memblock_set_node(mb->start, mb->end - mb->start, &memblock.memory, mb->nid); - - /* - * At this time, all memory regions reserved by memblock are - * used by the kernel. Set the nid in memblock.reserved will - * mark out all the nodes the kernel resides in. - */ - memblock_set_node(mb->start, mb->end - mb->start, - &memblock.reserved, mb->nid); } /* @@ -569,6 +561,17 @@ static void __init numa_clear_kernel_node_hotplug(void) unsigned long start, end; struct memblock_type *type = &memblock.reserved; + /* + * At this time, all memory regions reserved by memblock are + * used by the kernel. Set the nid in memblock.reserved will + * mark out all the nodes the kernel resides in. + */ + for (i = 0; i < numa_meminfo.nr_blks; i++) { + struct numa_memblk *mb = &numa_meminfo.blk[i]; + memblock_set_node(mb->start, mb->end - mb->start, + &memblock.reserved, mb->nid); + } + /* Mark all kernel nodes. */ for (i = 0; i < type->cnt; i++) node_set(type->regions[i].nid, numa_kernel_nodes); -- cgit v1.2.3