linux/arch/x86/kernel
Chang S. Bae 2beb4a53fc x86/signal: Detect and prevent an alternate signal stack overflow
The kernel pushes context on to the userspace stack to prepare for the
user's signal handler. When the user has supplied an alternate signal
stack, via sigaltstack(2), it is easy for the kernel to verify that the
stack size is sufficient for the current hardware context.

Check if writing the hardware context to the alternate stack will exceed
it's size. If yes, then instead of corrupting user-data and proceeding with
the original signal handler, an immediate SIGSEGV signal is delivered.

Refactor the stack pointer check code from on_sig_stack() and use the new
helper.

While the kernel allows new source code to discover and use a sufficient
alternate signal stack size, this check is still necessary to protect
binaries with insufficient alternate signal stack size from data
corruption.

Fixes: c2bc11f10a ("x86, AVX-512: Enable AVX-512 States Context Switch")
Reported-by: Florian Weimer <fweimer@redhat.com>
Suggested-by: Jann Horn <jannh@google.com>
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Len Brown <len.brown@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20210518200320.17239-6-chang.seok.bae@intel.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=153531
2021-05-19 12:40:30 +02:00
..
acpi Trivial cleanups and fixes all over the place. 2021-04-26 09:25:47 -07:00
apic A single commit to make the vector allocation code more resilent against an 2021-04-26 10:00:38 -07:00
cpu x86/signal: Introduce helpers to get the maximum signal frame size 2021-05-19 11:46:27 +02:00
fpu x86/signal: Introduce helpers to get the maximum signal frame size 2021-05-19 11:46:27 +02:00
kprobes - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
.gitignore
alternative.c The x86 MM changes in this cycle were: 2021-04-29 11:41:43 -07:00
amd_gart_64.c dma-mapping: split <linux/dma-mapping.h> 2020-10-06 07:07:03 +02:00
amd_nb.c x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
aperture_64.c
apm_32.c x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
asm-offsets.c x86/paravirt: Switch iret pvops to ALTERNATIVE 2021-03-11 19:58:54 +01:00
asm-offsets_32.c x86/stackprotector/32: Make the canary into a regular percpu variable 2021-03-08 13:19:05 +01:00
asm-offsets_64.c x86/xen: Drop USERGS_SYSRET64 paravirt call 2021-02-10 12:32:07 +01:00
audit_64.c
bootflag.c
check.c
cpuid.c smp: Cleanup smp_call_function*() 2020-11-24 16:47:49 +01:00
crash.c Devicetree updates for v5.13: 2021-04-28 15:50:24 -07:00
crash_core_32.c
crash_core_64.c
crash_dump_32.c x86/crashdump/32: Simplify copy_oldmem_page() 2020-11-24 14:42:09 +01:00
crash_dump_64.c
devicetree.c x86/devicetree: Fix the ioapic interrupt type table 2020-10-28 20:26:24 +01:00
doublefault_32.c x86/stackprotector/32: Make the canary into a regular percpu variable 2021-03-08 13:19:05 +01:00
dumpstack.c - Remove all uses of TIF_IA32 and TIF_X32 and reclaim the two bits in the end 2020-12-14 13:45:26 -08:00
dumpstack_32.c
dumpstack_64.c x86/irq/64: Adjust the per CPU irq stack pointer by 8 2021-02-10 23:34:14 +01:00
e820.c Power management updates for 5.13-rc1 2021-04-26 15:10:25 -07:00
early-quirks.c x86/gpu: Add Alderlake-S stolen memory support 2021-01-26 06:55:09 -08:00
early_printk.c
ebda.c
eisa.c
espfix_64.c
ftrace.c x86: Remove dynamic NOP selection 2021-03-15 16:24:59 +01:00
ftrace_32.S
ftrace_64.S x86/ftrace: Support objtool vmlinux.o validation in ftrace_64.S 2021-01-26 11:33:02 -06:00
head32.c
head64.c x86/sev-es: Rename sev-es.{ch} to sev.{ch} 2021-05-10 07:40:27 +02:00
head_32.S x86/stackprotector/32: Make the canary into a regular percpu variable 2021-03-08 13:19:05 +01:00
head_64.S - Fix the vmlinux size check on 64-bit along with adding useful clarifications on the topic 2020-12-14 13:54:50 -08:00
hpet.c x86/hpet: Use irq_find_matching_fwspec() to find remapping irqdomain 2020-10-28 20:26:28 +01:00
hw_breakpoint.c x86/debug: Prevent data breakpoints on cpu_dr7 2021-02-05 20:13:12 +01:00
i8237.c
i8253.c
i8259.c x86/i8259: Use printk_deferred() to prevent deadlock 2020-07-29 16:27:16 +02:00
idt.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
io_delay.c
ioport.c
irq.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
irq_32.c softirq: Move do_softirq_own_stack() to generic asm header 2021-02-10 23:34:16 +01:00
irq_64.c x86/softirq/64: Inline do_softirq_own_stack() 2021-02-10 23:34:17 +01:00
irq_work.c x86/entry: Convert various system vectors 2020-06-11 15:15:14 +02:00
irqflags.S x86/pv: Rework arch_local_irq_restore() to not use popf 2021-02-10 12:36:45 +01:00
irqinit.c x86/headers: Remove APIC headers from <asm/smp.h> 2020-08-06 16:13:09 +02:00
itmt.c
jailhouse.c locking/seqlock, headers: Untangle the spaghetti monster 2020-08-06 16:13:13 +02:00
jump_label.c x86: Remove dynamic NOP selection 2021-03-15 16:24:59 +01:00
kdebugfs.c
kexec-bzimage64.c x86: Use ELF fields defined in 'struct kimage' 2021-03-08 12:06:29 -07:00
kgdb.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
ksysfs.c
kvm.c x86/kvm: Unify kvm_pv_guest_cpu_reboot() with kvm_guest_cpu_offline() 2021-05-07 06:06:11 -04:00
kvmclock.c x86/kvm: Disable all PV features on crash 2021-05-07 06:06:10 -04:00
ldt.c x86/ldt: Use tlb_gather_mmu_fullmm() when freeing LDT page-tables 2021-01-29 20:02:29 +01:00
machine_kexec_32.c
machine_kexec_64.c Devicetree updates for v5.13: 2021-04-28 15:50:24 -07:00
Makefile x86/sev-es: Rename sev-es.{ch} to sev.{ch} 2021-05-10 07:40:27 +02:00
mmconf-fam10h_64.c x86/msr: Rename MSR_K8_SYSCFG to MSR_AMD64_SYSCFG 2021-05-10 07:51:38 +02:00
module.c x86/build: Treat R_386_PLT32 relocation as R_386_PC32 2021-01-28 12:24:06 +01:00
mpparse.c Surgery of the MSI interrupt handling to prepare the support of upcoming 2020-10-12 11:40:41 -07:00
msr.c x86/MSR: Filter MSR writes through X86_IOC_WRMSR_REGS ioctl too 2021-01-27 19:06:47 +01:00
nmi.c x86/sev-es: Rename sev-es.{ch} to sev.{ch} 2021-05-10 07:40:27 +02:00
nmi_selftest.c
paravirt-spinlocks.c x86/paravirt: Add new features for paravirt patching 2021-03-11 19:51:49 +01:00
paravirt.c The x86 MM changes in this cycle were: 2021-04-29 11:41:43 -07:00
pci-dma.c dma-mapping: move dma-debug.h to kernel/dma/ 2020-10-06 07:07:05 +02:00
pci-iommu_table.c x86: Remove definition of DEBUG 2021-01-15 08:23:10 +01:00
pci-swiotlb.c
pcspeaker.c
perf_regs.c - Remove all uses of TIF_IA32 and TIF_X32 and reclaim the two bits in the end 2020-12-14 13:45:26 -08:00
platform-quirks.c
pmem.c
probe_roms.c maccess: make get_kernel_nofault() check for minimal type compatibility 2020-06-18 12:10:37 -07:00
process.c x86/process: setup io_threads more like normal user space threads 2021-05-05 17:47:41 -06:00
process.h
process_32.c x86/dumpstack: Add log_lvl to __show_regs() 2020-07-22 23:56:53 +02:00
process_64.c x86/irq: Sanitize irq stack tracking 2021-02-10 23:34:13 +01:00
ptrace.c x86/ptrace: Clean up PTRACE_GETREGS/PTRACE_PUTREGS regset selection 2021-02-04 12:33:15 +01:00
pvclock.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
quirks.c x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}() 2020-10-06 11:18:04 +02:00
reboot.c x86: 2021-02-21 13:31:43 -08:00
reboot_fixups_32.c
relocate_kernel_32.S x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
relocate_kernel_64.S x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
resource.c
rtc.c
setup.c - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
setup_percpu.c x86/stackprotector/32: Make the canary into a regular percpu variable 2021-03-08 13:19:05 +01:00
sev-shared.c x86/sev: Move GHCB MSR protocol and NAE definitions in a common header 2021-05-10 07:46:39 +02:00
sev.c x86/sev-es: Rename sev-es.{ch} to sev.{ch} 2021-05-10 07:40:27 +02:00
sev_verify_cbit.S x86/boot/compressed/64: Check SEV encryption in 64-bit boot-path 2020-10-29 18:06:52 +01:00
signal.c x86/signal: Detect and prevent an alternate signal stack overflow 2021-05-19 12:40:30 +02:00
signal_compat.c signal: Introduce TRAP_PERF si_code and si_perf to siginfo 2021-04-16 16:32:41 +02:00
smp.c x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
smpboot.c x86, sched: Fix the AMD CPPC maximum performance value on certain AMD Ryzen generations 2021-05-13 12:10:24 +02:00
stacktrace.c stacktrace: Move documentation for arch_stack_walk_reliable() to header 2021-03-10 15:52:31 +01:00
static_call.c x86: Remove dynamic NOP selection 2021-03-15 16:24:59 +01:00
step.c entry: Ensure trap after single-step on system call return 2021-02-06 00:21:42 +01:00
sys_ia32.c x86: switch to kernel_clone() 2020-08-20 13:12:58 +02:00
sys_x86_64.c x86/mm: Refine mmap syscall implementation 2021-01-05 19:07:42 +01:00
sysfb.c
sysfb_efi.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
sysfb_simplefb.c
tboot.c x86/boot/tboot: Avoid Wstringop-overread-warning 2021-03-23 00:16:13 +01:00
time.c A set of fixes and updates for x86: 2020-06-11 15:54:31 -07:00
tls.c x86/stackprotector/32: Make the canary into a regular percpu variable 2021-03-08 13:19:05 +01:00
tls.h x86: switch to ->regset_get() 2020-07-27 14:31:07 -04:00
topology.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
trace_clock.c
tracepoint.c x86/entry: Convert reschedule interrupt to IDTENTRY_SYSVEC_SIMPLE 2020-06-11 15:15:16 +02:00
traps.c - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
tsc.c Trivial cleanups and fixes all over the place. 2021-04-26 09:25:47 -07:00
tsc_msr.c Misc fixes and small updates all around the place: 2020-08-15 10:38:03 -07:00
tsc_sync.c x86: Fix various typos in comments, take #2 2021-03-21 23:50:28 +01:00
umip.c - turn the stack canary into a normal __percpu variable on 32-bit which 2021-04-27 17:45:09 -07:00
unwind_frame.c fork-v5.9 2020-08-04 14:47:45 -07:00
unwind_guess.c
unwind_orc.c x86/unwind/orc: Silence warnings caused by missing ORC data 2021-03-06 13:09:45 +01:00
uprobes.c x86/uprobes: Convert to insn_decode() 2021-03-15 12:05:03 +01:00
verify_cpu.S
vm86_32.c x86/vm86/32: Remove VM86_SCREEN_BITMAP support 2021-01-21 20:08:53 +01:00
vmlinux.lds.S x86/build: Fix vmlinux size check on 64-bit 2020-10-29 21:54:35 +01:00
vsmp_64.c
x86_init.c x86/apic: Support 15 bits of APIC ID in MSI where available 2020-10-28 20:26:29 +01:00