linux/arch/x86/kernel
Robert Richter 1022623842 x86-32: Fix invalid stack address while in softirq
In 32 bit the stack address provided by kernel_stack_pointer() may
point to an invalid range causing NULL pointer access or page faults
while in NMI (see trace below). This happens if called in softirq
context and if the stack is empty. The address at &regs->sp is then
out of range.

Fixing this by checking if regs and &regs->sp are in the same stack
context. Otherwise return the previous stack pointer stored in struct
thread_info. If that address is invalid too, return address of regs.

 BUG: unable to handle kernel NULL pointer dereference at 0000000a
 IP: [<c1004237>] print_context_stack+0x6e/0x8d
 *pde = 00000000
 Oops: 0000 [#1] SMP
 Modules linked in:
 Pid: 4434, comm: perl Not tainted 3.6.0-rc3-oprofile-i386-standard-g4411a05 #4 Hewlett-Packard HP xw9400 Workstation/0A1Ch
 EIP: 0060:[<c1004237>] EFLAGS: 00010093 CPU: 0
 EIP is at print_context_stack+0x6e/0x8d
 EAX: ffffe000 EBX: 0000000a ECX: f4435f94 EDX: 0000000a
 ESI: f4435f94 EDI: f4435f94 EBP: f5409ec0 ESP: f5409ea0
  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
 CR0: 8005003b CR2: 0000000a CR3: 34ac9000 CR4: 000007d0
 DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
 DR6: ffff0ff0 DR7: 00000400
 Process perl (pid: 4434, ti=f5408000 task=f5637850 task.ti=f4434000)
 Stack:
  000003e8 ffffe000 00001ffc f4e39b00 00000000 0000000a f4435f94 c155198c
  f5409ef0 c1003723 c155198c f5409f04 00000000 f5409edc 00000000 00000000
  f5409ee8 f4435f94 f5409fc4 00000001 f5409f1c c12dce1c 00000000 c155198c
 Call Trace:
  [<c1003723>] dump_trace+0x7b/0xa1
  [<c12dce1c>] x86_backtrace+0x40/0x88
  [<c12db712>] ? oprofile_add_sample+0x56/0x84
  [<c12db731>] oprofile_add_sample+0x75/0x84
  [<c12ddb5b>] op_amd_check_ctrs+0x46/0x260
  [<c12dd40d>] profile_exceptions_notify+0x23/0x4c
  [<c1395034>] nmi_handle+0x31/0x4a
  [<c1029dc5>] ? ftrace_define_fields_irq_handler_entry+0x45/0x45
  [<c13950ed>] do_nmi+0xa0/0x2ff
  [<c1029dc5>] ? ftrace_define_fields_irq_handler_entry+0x45/0x45
  [<c13949e5>] nmi_stack_correct+0x28/0x2d
  [<c1029dc5>] ? ftrace_define_fields_irq_handler_entry+0x45/0x45
  [<c1003603>] ? do_softirq+0x4b/0x7f
  <IRQ>
  [<c102a06f>] irq_exit+0x35/0x5b
  [<c1018f56>] smp_apic_timer_interrupt+0x6c/0x7a
  [<c1394746>] apic_timer_interrupt+0x2a/0x30
 Code: 89 fe eb 08 31 c9 8b 45 0c ff 55 ec 83 c3 04 83 7d 10 00 74 0c 3b 5d 10 73 26 3b 5d e4 73 0c eb 1f 3b 5d f0 76 1a 3b 5d e8 73 15 <8b> 13 89 d0 89 55 e0 e8 ad 42 03 00 85 c0 8b 55 e0 75 a6 eb cc
 EIP: [<c1004237>] print_context_stack+0x6e/0x8d SS:ESP 0068:f5409ea0
 CR2: 000000000000000a
 ---[ end trace 62afee3481b00012 ]---
 Kernel panic - not syncing: Fatal exception in interrupt

V2:
* add comments to kernel_stack_pointer()
* always return a valid stack address by falling back to the address
  of regs

Reported-by: Yang Wei <wei.yang@windriver.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Link: http://lkml.kernel.org/r/20120912135059.GZ8285@erda.amd.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Jun Zhang <jun.zhang@intel.com>
2012-11-20 22:23:20 -08:00
..
acpi Merge branch 'x86-smap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-10-01 13:59:17 -07:00
apic x86/irq/ioapic: Check for valid irq_cfg pointer in smp_irq_move_cleanup_interrupt 2012-10-24 12:53:51 +02:00
cpu Fix problem in CMCI rediscovery code that was illegally 2012-11-13 19:01:01 +01:00
.gitignore
alternative.c Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-10-01 10:47:45 -07:00
amd_gart_64.c X86 & IA64: adapt for dma_map_ops changes 2012-03-28 16:36:31 +02:00
amd_nb.c Merge branch 'x86-mce-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-07-22 16:07:45 -07:00
apb_timer.c Merge branch 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-07-23 10:34:47 -07:00
aperture_64.c x86/gart: Fix kmemleak warning 2012-06-06 11:58:38 +02:00
apm_32.c x86/debug: Add KERN_<LEVEL> to bare printks, convert printks to pr_<level> 2012-06-06 09:17:22 +02:00
asm-offsets_32.c x86: Generate system call tables and unistd_*.h from tables 2011-11-17 13:35:37 -08:00
asm-offsets_64.c x32: If configured, add x32 system calls to system call tables 2012-02-20 12:52:06 -08:00
asm-offsets.c x86, um/x86: switch to generic sys_execve and kernel_execve 2012-09-30 22:53:32 -04:00
audit_64.c
bootflag.c
check.c x86: kernel/check.c simple_strtoul cleanup 2012-05-15 15:36:41 -07:00
cpuid.c Use get_online_cpus to avoid races involving CPU hotplug 2012-09-23 07:43:56 -07:00
crash_dump_32.c x86: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:15 +08:00
crash_dump_64.c
crash.c x86, nmi: Wire up NMI handlers to new routines 2011-10-10 06:56:57 +02:00
devicetree.c x86: dt: Use linear irq domain for ioapic(s) 2012-08-21 22:16:57 +02:00
doublefault_32.c
dumpstack_32.c x86: Move call to print_modules() out of show_regs() 2012-06-20 14:33:48 +02:00
dumpstack_64.c x86: Move call to print_modules() out of show_regs() 2012-06-20 14:33:48 +02:00
dumpstack.c x86: Move call to print_modules() out of show_regs() 2012-06-20 14:33:48 +02:00
e820.c x86, mm: Trim memory in memblock to be page aligned 2012-10-24 11:52:21 -07:00
early_printk.c Revert "x86/early_printk: Replace obsolete simple_strtoul() usage with kstrtoint()" 2012-07-22 15:47:52 +02:00
early-quirks.c
entry_32.S Merge commit 'v3.7-rc1' into stable/for-linus-3.7 2012-10-19 15:19:19 -04:00
entry_64.S Merge commit 'v3.7-rc1' into stable/for-linus-3.7 2012-10-19 15:19:19 -04:00
ftrace.c ftrace/x86: Add save_regs for i386 function calls 2012-07-19 13:20:37 -04:00
head32.c x86, realmode: Move ACPI wakeup to unified realmode code 2012-05-08 11:46:05 -07:00
head64.c x86, realmode: Move ACPI wakeup to unified realmode code 2012-05-08 11:46:05 -07:00
head_32.S x86-32: Start out eflags and cr4 clean 2012-09-26 15:06:22 -07:00
head_64.S Merge branch 'x86-trampoline-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-05-29 20:14:53 -07:00
head.c memblock, x86: Replace memblock_x86_reserve/free_range() with generic ones 2011-07-14 11:47:53 -07:00
hpet.c x86: hpet: Fix copy-and-paste mistake in earlier change 2012-05-25 15:32:29 +02:00
hw_breakpoint.c
i386_ksyms_32.c
i387.c x86, kvm: fix kvm's usage of kernel_fpu_begin/end() 2012-09-21 16:59:04 -07:00
i8237.c
i8253.c x86: Use common i8253 clockevent 2011-07-01 10:37:14 +02:00
i8259.c x86/irq/i8259: Fix incorrect comment 2012-08-22 09:34:24 +02:00
io_delay.c
ioport.c
irq_32.c x86: Use common threadinfo allocator 2012-05-08 14:08:44 +02:00
irq_64.c x86: Add stack top margin for stack overflow checking 2011-12-07 09:27:11 +01:00
irq_work.c
irq.c Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-10-01 11:13:33 -07:00
irqinit.c x86/tlb: replace INVALIDATE_TLB_VECTOR by CALL_FUNCTION_VECTOR 2012-06-27 19:29:13 -07:00
jump_label.c jump_label, x86: Fix section mismatch 2011-12-06 20:41:02 +01:00
kdebugfs.c arch/x86/kernel/kdebugfs.c: Ensure a consistent return value in error case 2012-07-26 15:07:20 +02:00
kgdb.c kgdb,x86: fix warning about unused variable 2012-10-12 06:37:34 -05:00
kprobes-common.h x86/kprobes: Split out optprobe related code to kprobes-opt.c 2012-03-06 09:49:49 +01:00
kprobes-opt.c x86/kprobes: Split out optprobe related code to kprobes-opt.c 2012-03-06 09:49:49 +01:00
kprobes.c kprobes/x86: Move skip_singlestep up 2012-09-20 14:48:16 +02:00
kvm.c KVM guest: exit idleness when handling KVM_PV_REASON_PAGE_NOT_PRESENT 2012-10-22 18:03:28 +02:00
kvmclock.c x86: kvmclock: remove check_and_clear_guest_paused warning 2012-06-11 23:18:33 -03:00
ldt.c Disintegrate asm/system.h for X86 2012-03-28 18:11:12 +01:00
machine_kexec_32.c Disintegrate asm/system.h for X86 2012-03-28 18:11:12 +01:00
machine_kexec_64.c
Makefile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-10-10 12:02:25 +09:00
microcode_amd.c x86, microcode_amd: Change email addresses, MAINTAINERS entry 2012-10-30 10:05:52 +01:00
microcode_core.c Merge branch 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-10-01 11:15:17 -07:00
microcode_intel.c x86, microcode: Add a refresh firmware flag to ->request_microcode_fw 2012-08-22 16:15:58 -07:00
mmconf-fam10h_64.c
module.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-07-24 13:34:56 -07:00
mpparse.c Merge branch 'x86-trampoline-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-05-29 20:14:53 -07:00
msr.c Use get_online_cpus to avoid races involving CPU hotplug 2012-09-23 07:43:56 -07:00
nmi_selftest.c x86/nmi: Clean up register_nmi_handler() usage 2012-06-20 14:23:17 +02:00
nmi.c x86: Save cr2 in NMI in case NMIs take a page fault (for i386) 2012-06-08 18:51:12 -04:00
paravirt_patch_32.c
paravirt_patch_64.c
paravirt-spinlocks.c
paravirt.c x86, pvops: Remove hooks for {rd,wr}msr_safe_regs 2012-06-07 11:41:08 -07:00
pci-calgary_64.c x86/debug: Add KERN_<LEVEL> to bare printks, convert printks to pr_<level> 2012-06-06 09:17:22 +02:00
pci-dma.c iommu: Remove group_mf 2012-06-25 13:48:30 +02:00
pci-iommu_table.c
pci-nommu.c X86: integrate CMA with DMA-mapping subsystem 2012-05-21 15:09:38 +02:00
pci-swiotlb.c X86 & IA64: adapt for dma_map_ops changes 2012-03-28 16:36:31 +02:00
pcspeaker.c
perf_regs.c perf: Fix off by one test in perf_reg_value() 2012-09-19 17:08:40 +02:00
probe_roms.c x86/pci/probe_roms: Add missing __iomem annotation to pci_map_biosrom() 2012-09-05 10:52:25 +02:00
process_32.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-10-10 12:02:25 +09:00
process_64.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-10-10 12:02:25 +09:00
process.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-10-10 12:02:25 +09:00
ptrace.c x86-32: Fix invalid stack address while in softirq 2012-11-20 22:23:20 -08:00
pvclock.c
quirks.c x86/PCI: move fixup hooks from __init to __devinit 2012-06-12 09:10:54 -06:00
reboot_fixups_32.c
reboot.c x86/reboot: Remove quirk entry for SBC FITPC 2012-10-04 12:22:32 +02:00
relocate_kernel_32.S kexec, x86: Fix incorrect jump back address if not preserving context 2011-07-21 11:19:28 +02:00
relocate_kernel_64.S kexec, x86: Fix incorrect jump back address if not preserving context 2011-07-21 11:19:28 +02:00
resource.c
rtc.c sections: fix section conflicts in arch/x86 2012-10-06 03:04:40 +09:00
setup_percpu.c x86: Add read_mostly declaration/definition to variables from smp.h 2012-06-14 12:42:11 +02:00
setup.c EFI updates for 3.7 2012-10-26 10:17:38 +02:00
signal.c Merge branch 'uprobes/core' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc into perf/urgent 2012-10-21 18:18:17 +02:00
smp.c x86/reboot: Update nonmi_ipi parameter 2012-05-14 11:49:38 +02:00
smpboot.c x86/smp: Don't ever patch back to UP if we unplug cpus 2012-08-23 10:45:13 +02:00
stacktrace.c x86: Swap save_stack_trace_regs parameters 2011-06-14 22:48:51 -04:00
step.c uprobes/x86: Do not (ab)use TIF_SINGLESTEP/user_*_single_step() for single-stepping 2012-09-15 17:37:30 +02:00
sys_x86_64.c Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 18:12:23 -07:00
syscall_32.c x86, syscall: Re-fix typo in comment 2011-11-18 16:25:07 -08:00
syscall_64.c x32: If configured, add x32 system calls to system call tables 2012-02-20 12:52:06 -08:00
tboot.c x86, realmode: fixes compilation issue in tboot.c 2012-05-08 15:04:27 -07:00
tce_64.c Disintegrate asm/system.h for X86 2012-03-28 18:11:12 +01:00
test_nx.c
test_rodata.c x86, extable: Remove open-coded exception table entries in arch/x86/kernel/test_rodata.c 2012-04-20 13:51:38 -07:00
time.c MCA: delete all remaining traces of microchannel bus support. 2012-05-17 19:06:13 -04:00
tls.c Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 14:28:26 -07:00
tls.h
topology.c x86: Fix files explicitly requiring export.h for EXPORT_SYMBOL/THIS_MODULE 2011-10-31 19:30:35 -04:00
traps.c Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-10-01 11:10:52 -07:00
tsc_sync.c x86/tsc: Reduce the TSC sync check time for core-siblings 2012-02-22 11:49:40 +01:00
tsc.c x86/debug: Add KERN_<LEVEL> to bare printks, convert printks to pr_<level> 2012-06-06 09:17:22 +02:00
uprobes.c uprobes/x86: Only rep+nop can be emulated correctly 2012-10-07 21:19:40 +02:00
verify_cpu.S
vm86_32.c x86: get rid of TIF_IRET hackery 2012-09-20 09:50:17 -04:00
vmlinux.lds.S x86, realmode: Move ACPI wakeup to unified realmode code 2012-05-08 11:46:05 -07:00
vsmp_64.c x86/apic/x2apic: Limit the vector reservation to the user specified mask 2012-07-06 11:00:22 +02:00
vsyscall_64.c time: Convert x86_64 to using new update_vsyscall 2012-09-24 12:38:09 -04:00
vsyscall_emu_64.S x86-64: Rework vsyscall emulation and add vsyscall= parameter 2011-08-10 19:26:46 -05:00
vsyscall_trace.h x86-64: Add vsyscall:emulate_vsyscall trace event 2011-08-04 16:13:53 -07:00
x86_init.c x86: xen: Cleanup and remove x86_init.paging.pagetable_setup_done() 2012-09-12 15:33:06 +02:00
x8664_ksyms_64.c ftrace/x86: Add support for -mfentry to x86_64 2012-08-23 11:26:36 -04:00
xsave.c x86, smap: Do not abuse the [f][x]rstor_checking() functions for user space 2012-09-25 15:42:18 -07:00