linux_dsm_epyc7002/arch
Dave Young 22ef882e6b 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>
2015-04-07 16:01:19 +02:00
..
alpha asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
arc ARC: signal handling robustify 2015-03-26 11:19:36 +05:30
arm ARM: SoC fixes 2015-03-29 15:09:31 -07:00
arm64 ARM: SoC fixes 2015-03-29 15:09:31 -07:00
avr32 asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
blackfin Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2015-02-21 12:59:04 -08:00
c6x arch/c6x/include/asm/pgtable.h: define dummy pgprot_writecombine for !MMU 2015-03-12 18:46:08 -07:00
cris CRIS changes for 3.20 2015-02-15 18:02:02 -08:00
frv mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
hexagon all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
ia64 asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
m32r mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
m68k mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
metag metag: Fix ioremap_wc/ioremap_cached build errors 2015-03-23 12:32:37 +00:00
microblaze microblaze: Fix syscall error recovery for invalid syscall IDs 2015-03-04 15:12:27 +01:00
mips KVM: MIPS: Enable after disabling interrupt 2015-03-02 19:18:12 -03:00
mn10300 mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
nios2 nios2: mm: do not invoke OOM killer on kernel fault OOM 2015-03-16 15:35:25 +08:00
openrisc asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
parisc parisc: Fix pmd code to depend on PT_NLEVELS value, not on CONFIG_64BIT 2015-03-23 12:28:16 +01:00
powerpc powerpc: fix memory corruption by pnv_alloc_idle_core_states 2015-04-01 12:05:44 +11:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2015-03-26 14:11:17 -07:00
score all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
sh asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
sparc sparc64: Fix several bugs in memmove(). 2015-03-23 09:22:10 -07:00
tile tile: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:37 -08:00
um all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
unicore32 mm: vmalloc: pass additional vm_flags to __vmalloc_node_range() 2015-02-13 21:21:42 -08:00
x86 x86/mm/numa: Fix kernel stack corruption in numa_init()->numa_clear_kernel_node_hotplug() 2015-04-07 16:01:19 +02:00
xtensa asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
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