linux/arch/x86
Thomas Gleixner 008f1d60fe x86/apic/vector: Force interupt handler invocation to irq context
Sathyanarayanan reported that the PCI-E AER error injection mechanism
can result in a NULL pointer dereference in apic_ack_edge():

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
 RIP: 0010:apic_ack_edge+0x1e/0x40
 Call Trace:
   handle_edge_irq+0x7d/0x1e0
   generic_handle_irq+0x27/0x30
   aer_inject_write+0x53a/0x720

It crashes in irq_complete_move() which dereferences get_irq_regs() which
is obviously NULL when this is called from non interrupt context.

Of course the pointer could be checked, but that just papers over the real
issue. Invoking the low level interrupt handling mechanism from random code
can wreckage the fragile interrupt affinity mechanism of x86 as interrupts
can only be moved in interrupt context or with special care when a CPU goes
offline and the move has to be enforced.

In the best case this triggers the warning in the MSI affinity setter, but
if the call happens on the correct CPU it just corrupts state and might
prevent further interrupt delivery for the affected device.

Mark the APIC interrupts as unsuitable for being invoked in random contexts.

This prevents the AER injection from proliferating the wreckage, but that's
less broken than the current state of affairs and more correct than just
papering over the problem by sprinkling random checks all over the place
and silently corrupting state.

Reported-by: sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200306130623.684591280@linutronix.de
2020-03-08 11:06:40 +01:00
..
boot x86/boot/compressed: Don't declare __force_order in kaslr_64.c 2020-02-19 17:23:59 +01:00
configs x86: Remove the calgary IOMMU driver 2019-11-15 10:36:59 +01:00
crypto crypto: x86/poly1305 - emit does base conversion itself 2020-01-22 16:21:11 +08:00
entry kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
events perf/x86/intel: Fix inaccurate period in context switch for auto-reload 2020-02-11 13:23:27 +01:00
hyperv x86/hyperv: Suspend/resume the hypercall page for hibernation 2020-02-01 09:41:16 +01:00
ia32 x86: Remove force_iret() 2020-01-08 19:40:51 +01:00
include Bugfixes, including the fix for CVE-2020-2732 and a few 2020-02-24 11:48:17 -08:00
kernel x86/apic/vector: Force interupt handler invocation to irq context 2020-03-08 11:06:40 +01:00
kvm KVM: VMX: check descriptor table exits on instruction emulation 2020-03-01 19:26:31 +01:00
lib Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-31 11:05:33 -08:00
math-emu Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 10:42:40 -08:00
mm x86: mm: avoid allocating struct mm_struct on the stack 2020-02-04 03:05:25 +00:00
net bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS 2020-01-09 08:46:18 -08:00
oprofile x86: Use pr_warn instead of pr_warning 2019-10-18 15:00:18 +02:00
pci pci-v5.6-changes 2020-01-31 14:48:54 -08:00
platform A single fix for a EFI boot regression on X86 which was caused by the 2020-02-09 11:54:50 -08:00
power x86/asm/32: Change all ENTRY+ENDPROC to SYM_FUNC_* 2019-10-18 12:03:43 +02:00
purgatory Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 10:42:40 -08:00
ras
realmode kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
tools kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
um um: Implement copy_thread_tls 2020-01-07 13:31:29 +01:00
video
xen xen: branch for v5.6-rc3 2020-02-21 16:10:10 -08:00
.gitignore
Kbuild
Kconfig asm-generic/tlb: rename HAVE_RCU_TABLE_FREE 2020-02-04 03:05:26 +00:00
Kconfig.cpu x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs 2020-01-13 18:02:53 +01:00
Kconfig.debug x86: mm: convert dump_pagetables to use walk_page_range 2020-02-04 03:05:25 +00:00
Makefile x86/build: Add -Wnoaddress-of-packed-member to REALMODE_CFLAGS, to silence GCC9 build warning 2019-08-28 17:31:31 +02:00
Makefile_32.cpu x86/math-emu: Limit MATH_EMULATION to 486SX compatibles 2019-10-03 10:51:17 +02:00
Makefile.um