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authorDave Young <dyoung@redhat.com>2015-04-07 21:41:32 +0800
committerIngo Molnar <mingo@kernel.org>2015-04-07 16:01:19 +0200
commit22ef882e6b5bd2bf668d10b1e2be3dc2fc365b99 (patch)
treead52155c473c959e8c9dfce70598c7752198259a /arch/x86/mm
parentf22e6e847115abc3a0e2ad7bb18d243d42275af1 (diff)
downloadlinux-22ef882e6b5bd2bf668d10b1e2be3dc2fc365b99.tar.bz2
x86/mm/numa: Fix kernel stack corruption in numa_init()->numa_clear_kernel_node_hotplug()
I got below kernel panic during kdump test on Thinkpad T420 laptop: [ 0.000000] No NUMA configuration found [ 0.000000] Faking a node at [mem 0x0000000000000000-0x0000000037ba4fff] [ 0.000000] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff81d21910 ... [ 0.000000] Call Trace: [ 0.000000] [<ffffffff817c2a26>] dump_stack+0x45/0x57 [ 0.000000] [<ffffffff817bc8d2>] panic+0xd0/0x204 [ 0.000000] [<ffffffff81d21910>] ? numa_clear_kernel_node_hotplug+0xe6/0xf2 [ 0.000000] [<ffffffff8107741b>] __stack_chk_fail+0x1b/0x20 [ 0.000000] [<ffffffff81d21910>] numa_clear_kernel_node_hotplug+0xe6/0xf2 [ 0.000000] [<ffffffff81d21e5d>] numa_init+0x1a5/0x520 [ 0.000000] [<ffffffff81d222b1>] x86_numa_init+0x19/0x3d [ 0.000000] [<ffffffff81d22460>] initmem_init+0x9/0xb [ 0.000000] [<ffffffff81d0d00c>] setup_arch+0x94f/0xc82 [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 [ 0.000000] [<ffffffff817bd0bb>] ? printk+0x55/0x6b [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 [ 0.000000] [<ffffffff81d05d9b>] start_kernel+0xe8/0x4d6 [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 [ 0.000000] [<ffffffff81d055ee>] x86_64_start_reservations+0x2a/0x2c [ 0.000000] [<ffffffff81d05751>] x86_64_start_kernel+0x161/0x184 [ 0.000000] ---[ end Kernel panic - not syncing: stack-protector: Kernel sta This is caused by writing over the end of numa mask bitmap in numa_clear_kernel_node(). numa_clear_kernel_node() tries to set the node id in a mask bitmap, by iterating all reserved regions and assuming that every region has a valid nid. This assumption is not true because there's an exception for some graphic memory quirks. See trim_snb_memory() in arch/x86/kernel/setup.c It is easily to reproduce the bug in the kdump kernel because kdump kernel use pre-reserved memory instead of the whole memory, but kexec pass other reserved memory ranges to 2nd kernel as well. like below in my test: kdump kernel ram 0x2d000000 - 0x37bfffff One of the reserved regions: 0x40000000 - 0x40100000 which includes 0x40004000, a page excluded in trim_snb_memory(). For this memblock reserved region the nid is not set, it is still default value MAX_NUMNODES. later node_set will set bit MAX_NUMNODES thus stack corruption happen. This also happens when booting with mem= kernel commandline during my test. Fixing it by adding a check, do not call node_set in case nid is MAX_NUMNODES. Signed-off-by: Dave Young <dyoung@redhat.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bhe@redhat.com Cc: qiuxishi@huawei.com Link: http://lkml.kernel.org/r/20150407134132.GA23522@dhcp-16-198.nay.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/mm')
-rw-r--r--arch/x86/mm/numa.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index cd4785bbacb9..4053bb58bf92 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -482,9 +482,16 @@ static void __init numa_clear_kernel_node_hotplug(void)
&memblock.reserved, mb->nid);
}
- /* Mark all kernel nodes. */
+ /*
+ * Mark all kernel nodes.
+ *
+ * When booting with mem=nn[kMG] or in a kdump kernel, numa_meminfo
+ * may not include all the memblock.reserved memory ranges because
+ * trim_snb_memory() reserves specific pages for Sandy Bridge graphics.
+ */
for_each_memblock(reserved, r)
- node_set(r->nid, numa_kernel_nodes);
+ if (r->nid != MAX_NUMNODES)
+ node_set(r->nid, numa_kernel_nodes);
/* Clear MEMBLOCK_HOTPLUG flag for memory in kernel nodes. */
for (i = 0; i < numa_meminfo.nr_blks; i++) {