linux/arch/mips/kernel
Paul Burton b1442d39fa MIPS: Prevent user from setting FCSR cause bits
If one or more matching FCSR cause & enable bits are set in saved thread
context then when that context is restored the kernel will take an FP
exception. This is of course undesirable and considered an oops, leading
to the kernel writing a backtrace to the console and potentially
rebooting depending upon the configuration. Thus the kernel avoids this
situation by clearing the cause bits of the FCSR register when handling
FP exceptions and after emulating FP instructions.

However the kernel does not prevent userland from setting arbitrary FCSR
cause & enable bits via ptrace, using either the PTRACE_POKEUSR or
PTRACE_SETFPREGS requests. This means userland can trivially cause the
kernel to oops on any system with an FPU. Prevent this from happening
by clearing the cause bits when writing to the saved FCSR context via
ptrace.

This problem appears to exist at least back to the beginning of the git
era in the PTRACE_POKEUSR case.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: stable@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7438/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-07-30 19:30:39 +02:00
..
.gitignore
8250-platform.c mips: remove needless include of module.h from core kernel files. 2011-10-31 19:30:57 -04:00
asm-offsets.c Revert "MIPS: Save/restore MSA context around signals" 2014-06-26 10:48:18 +01:00
binfmt_elfn32.c MIPS: Compat: Fix cputime_to_timeval() arguments in compat binfmt_elf. 2013-06-06 16:11:26 +02:00
binfmt_elfo32.c MIPS: Support for 64-bit FP with O32 binaries 2014-01-13 23:40:56 +01:00
bmips_vec.S MIPS: Fix gigaton of warning building with microMIPS. 2014-03-31 18:17:12 +02:00
branch.c Merge branch '3.15-fixes' into mips-for-linux-next 2014-06-04 22:53:02 +02:00
cevt-bcm1480.c MIPS: Delete __cpuinit/__CPUINIT usage from MIPS code 2013-07-14 19:36:51 -04:00
cevt-ds1287.c MIPS: Whitespace cleanup. 2013-02-01 10:00:22 +01:00
cevt-gic.c MIPS: allow GIC clockevent device config from other CPUs 2014-05-02 16:39:11 +01:00
cevt-gt641xx.c MIPS: Whitespace cleanup. 2013-02-01 10:00:22 +01:00
cevt-r4k.c Merge branch 'wip-mips-pm' of https://github.com/paulburton/linux into mips-for-linux-next 2014-05-29 15:08:23 +02:00
cevt-sb1250.c MIPS: Delete __cpuinit/__CPUINIT usage from MIPS code 2013-07-14 19:36:51 -04:00
cevt-txx9.c MIPS: Whitespace cleanup. 2013-02-01 10:00:22 +01:00
cps-vec.S MIPS: smp-cps: duplicate core0 CCA on secondary cores 2014-05-28 16:20:33 +01:00
cpu-bugs64.c MIPS: Delete __cpuinit/__CPUINIT usage from MIPS code 2013-07-14 19:36:51 -04:00
cpu-probe.c MIPS: Add function get_ebase_cpunum 2014-05-30 21:01:11 +02:00
crash.c mips: delete non-required instances of include <linux/init.h> 2014-01-24 22:39:56 +01:00
crash_dump.c mips: remove savemaxmem parameter setup 2013-07-03 16:08:03 -07:00
csrc-bcm1480.c MIPS: Whitespace cleanup. 2013-02-01 10:00:22 +01:00
csrc-gic.c MIPS: Refactor GIC clocksource code. 2013-05-09 17:55:20 +02:00
csrc-ioasic.c MIPS: DECstation HRT initialization rearrangement 2013-09-13 11:56:13 +02:00
csrc-r4k.c
csrc-sb1250.c MIPS: Whitespace cleanup. 2013-02-01 10:00:22 +01:00
early_printk.c early_printk: consolidate random copies of identical code 2013-04-29 18:28:13 -07:00
early_printk_8250.c MIPS: Add 8250/16550 serial early printk driver 2013-10-29 21:24:36 +01:00
entry.S MIPS: MT: Remove SMTC support 2014-05-24 00:07:01 +02:00
ftrace.c Most of the changes were largely clean ups, and some documentation. 2014-04-03 10:26:31 -07:00
genex.S MIPS: MT: Remove SMTC support 2014-05-24 00:07:01 +02:00
gpio_txx9.c
head.S MIPS: MT: Remove SMTC support 2014-05-24 00:07:01 +02:00
i8253.c MIPS: irq: Remove IRQF_DISABLED 2011-12-07 22:03:45 +00:00
i8259.c MIPS: MT: Remove SMTC support 2014-05-24 00:07:01 +02:00
idle.c Merge branch 'wip-mips-pm' of https://github.com/paulburton/linux into mips-for-linux-next 2014-05-29 15:08:23 +02:00
irq-gic.c MIPS: allow GIC clockevent device config from other CPUs 2014-05-02 16:39:11 +01:00
irq-gt641xx.c MIPS: Whitespace cleanup. 2013-02-01 10:00:22 +01:00
irq-msc01.c MIPS: MSC: Prevent out-of-bounds writes to MIPS SC ioremap'd region 2014-06-26 10:48:23 +01:00
irq-rm7000.c MIPS: Whitespace cleanup. 2013-02-01 10:00:22 +01:00
irq.c Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2014-06-09 18:10:34 -07:00
irq_cpu.c MIPS: Panic messages should not end in \n. 2013-10-29 21:24:19 +01:00
irq_txx9.c MIPS: Whitespace cleanup. 2013-02-01 10:00:22 +01:00
jump_label.c
kgdb.c MIPS: kernel: {ftrace,kgdb}: Set correct address limit for cache flushes 2014-03-26 23:09:18 +01:00
kprobes.c kprobes/mips: Fix to check double free of insn slot 2013-05-22 12:48:30 +02:00
linux32.c unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE 2013-05-09 13:46:38 -04:00
machine_kexec.c MIPS: kdump: Add support 2012-12-13 16:46:47 +01:00
Makefile MIPS: OCTEON: Enable use of FPU 2014-05-30 21:01:09 +02:00
mcount.S MIPS: Ftrace: Fix function tracing return address to match 2013-09-03 14:46:27 +02:00
mips-cm.c MIPS: Add generic CM probe & access code 2014-03-06 21:25:22 +01:00
mips-cpc.c MIPS: smp-cps: rework core/VPE initialisation 2014-05-28 16:20:28 +01:00
mips-mt-fpaff.c MIPS: MT: Remove SMTC support 2014-05-24 00:07:01 +02:00
mips-mt.c MIPS: MT: Remove SMTC support 2014-05-24 00:07:01 +02:00
mips_ksyms.c MIPS: checksum: Split the 'copy_user' symbol 2014-03-26 23:09:17 +01:00
mips_machine.c MIPS: move mips_{set,get}_machine_name() to a more generic place 2013-05-08 01:19:07 +02:00
module-rela.c MIPS: Whitespace cleanup. 2013-02-01 10:00:22 +01:00
module.c MIPS: Use NUMA_NO_NODE instead of -1 for node ID. 2013-10-29 21:24:14 +01:00
octeon_switch.S MIPS: OCTEON: Enable use of FPU 2014-05-30 21:01:09 +02:00
perf_event.c MIPS: perf: Reorganize contents of perf support files. 2011-10-24 23:34:26 +01:00
perf_event_mipsxx.c MIPS: perf: Add interAptiv support 2014-03-31 18:17:12 +02:00
pm-cps.c MIPS: pm-cps: convert smp_mb__*() 2014-06-16 12:47:47 +01:00
pm.c MIPS: PM: Implement PM helper macros 2014-05-02 16:39:10 +01:00
proc.c Revert "MIPS: MT: proc: Add support for printing VPE and TC ids" 2014-05-13 00:29:33 +02:00
process.c MIPS: MT: Remove SMTC support 2014-05-24 00:07:01 +02:00
prom.c mips: convert fdt pointers to opaque pointers 2014-04-30 00:59:13 -05:00
ptrace.c MIPS: Prevent user from setting FCSR cause bits 2014-07-30 19:30:39 +02:00
ptrace32.c MIPS: Simplify PTRACE_PEEKUSR for FPC_EIR 2014-03-31 18:17:12 +02:00
r4k_fpu.S Revert "MIPS: Save/restore MSA context around signals" 2014-06-26 10:48:18 +01:00
r4k_switch.S MIPS: OCTEON: Enable use of FPU 2014-05-30 21:01:09 +02:00
r2300_fpu.S MIPS: Whitespace cleanup. 2013-02-01 10:00:22 +01:00
r2300_switch.S MIPS: stack protector: Fix per-task canary switch 2013-10-07 15:31:04 +02:00
r6000_fpu.S
relocate_kernel.S MIPS: kdump: Skip walking indirection page for crashkernels 2013-09-05 20:53:37 +02:00
reset.c mips: migrate core kernel file from module.h --> export.h 2011-10-31 19:30:56 -04:00
rtlx-cmp.c MIPS: APRP: Unregister rtlx interrupt hook at module exit 2014-03-06 20:55:07 +01:00
rtlx-mt.c MIPS: MT: Remove SMTC support 2014-05-24 00:07:01 +02:00
rtlx.c MIPS: APRP: Code formatting clean-ups. 2014-01-22 20:19:02 +01:00
scall32-o32.S MIPS: Wire up renameat2 syscall. 2014-05-13 17:57:33 +02:00
scall64-64.S MIPS: Wire up renameat2 syscall. 2014-05-13 17:57:33 +02:00
scall64-n32.S MIPS: Wire up renameat2 syscall. 2014-05-13 17:57:33 +02:00
scall64-o32.S MIPS: Wire up renameat2 syscall. 2014-05-13 17:57:33 +02:00
segment.c MIPS: Add debugfs file to print the segmentation control registers 2014-01-22 20:19:00 +01:00
setup.c MIPS: Fix start of free memory when using initrd 2013-10-29 21:24:23 +01:00
signal-common.h most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set 2012-06-01 12:58:51 -04:00
signal.c Revert "MIPS: Save/restore MSA context around signals" 2014-06-26 10:48:18 +01:00
signal32.c Revert "MIPS: Save/restore MSA context around signals" 2014-06-26 10:48:18 +01:00
signal_n32.c Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2013-03-02 07:44:16 -08:00
smp-bmips.c MIPS: SMP: Remove plat_smp_ops cpus_done method. 2014-05-27 11:06:42 +02:00
smp-cmp.c MIPS: SMP: Remove plat_smp_ops cpus_done method. 2014-05-27 11:06:42 +02:00
smp-cps.c MIPS: smp-cps: Convert smp_mb__after_atomic_dec() 2014-06-16 12:47:47 +01:00
smp-gic.c cpuidle: cpuidle-cps: add MIPS CPS cpuidle driver 2014-05-28 16:20:36 +01:00
smp-mt.c MIPS: SMP: Remove plat_smp_ops cpus_done method. 2014-05-27 11:06:42 +02:00
smp-up.c MIPS: SMP: Remove plat_smp_ops cpus_done method. 2014-05-27 11:06:42 +02:00
smp.c Merge branch 'wip-mips-pm' of https://github.com/paulburton/linux into mips-for-linux-next 2014-05-29 15:08:23 +02:00
spinlock_test.c mips: migrate core kernel file from module.h --> export.h 2011-10-31 19:30:56 -04:00
spram.c MIPS: Use current_cpu_type() instead of c->cputype 2014-03-31 18:17:12 +02:00
stacktrace.c mips: migrate core kernel file from module.h --> export.h 2011-10-31 19:30:56 -04:00
sync-r4k.c MIPS: MT: Remove SMTC support 2014-05-24 00:07:01 +02:00
syscall.c MIPS: Fix gigaton of warning building with microMIPS. 2014-03-31 18:17:12 +02:00
time.c MIPS: MT: Remove SMTC support 2014-05-24 00:07:01 +02:00
topology.c
traps.c Merge branch '3.15-fixes' into mips-for-linux-next 2014-06-04 22:53:02 +02:00
unaligned.c MIPS: kernel: unaligned: Handle unaligned accesses for EVA 2014-03-26 23:09:16 +01:00
vdso.c coredump: remove VM_ALWAYSDUMP flag 2012-03-23 16:58:42 -07:00
vmlinux.lds.S MIPS: Discard .eh_frame sections in linker script. 2013-08-26 15:33:41 +02:00
vpe-cmp.c MIPS: APRP: Add VPE loader support for CMP platforms. 2014-01-22 20:19:02 +01:00
vpe-mt.c MIPS: MT: Remove SMTC support 2014-05-24 00:07:01 +02:00
vpe.c Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2014-01-30 17:20:32 -08:00
watch.c MIPS: Delete __cpuinit/__CPUINIT usage from MIPS code 2013-07-14 19:36:51 -04:00