linux/arch/x86
Andy Lutomirski 653bc77af6 x86_64, entry: Fix out of bounds read on sysenter
Rusty noticed a Really Bad Bug (tm) in my NT fix.  The entry code
reads out of bounds, causing the NT fix to be unreliable.  But, and
this is much, much worse, if your stack is somehow just below the
top of the direct map (or a hole), you read out of bounds and crash.

Excerpt from the crash:

[    1.129513] RSP: 0018:ffff88001da4bf88  EFLAGS: 00010296

  2b:*    f7 84 24 90 00 00 00     testl  $0x4000,0x90(%rsp)

That read is deterministically above the top of the stack.  I
thought I even single-stepped through this code when I wrote it to
check the offset, but I clearly screwed it up.

Fixes: 8c7aa698ba ("x86_64, entry: Filter RFLAGS.NT on entry from userspace")
Reported-by: Rusty Russell <rusty@ozlabs.org>
Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-31 18:47:09 -07:00
..
boot Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-23 14:45:09 -07:00
configs
crypto
ia32 x86_64, entry: Fix out of bounds read on sysenter 2014-10-31 18:47:09 -07:00
include sched: stop the unbound recursion in preempt_schedule_context() 2014-10-28 10:46:05 +01:00
kernel Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-31 14:30:16 -07:00
kvm KVM: x86: Wrong assertion on paging_tmpl.h 2014-10-24 13:30:37 +02:00
lguest
lib
math-emu
mm x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE 2014-10-29 10:57:21 +01:00
net x86: bpf_jit: fix two bugs in eBPF JIT compiler 2014-10-14 13:13:14 -04:00
oprofile
pci
platform Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-31 14:30:16 -07:00
power
purgatory
realmode
syscalls
tools
um Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
vdso
video
xen x86/xen: panic on bad Xen-provided memory map 2014-10-23 16:24:02 +01:00
.gitignore
Kbuild kexec: create a new config option CONFIG_KEXEC_FILE for new syscall 2014-08-29 16:28:16 -07:00
Kconfig perf/x86: Fix compile warnings for intel_uncore 2014-10-28 10:51:03 +01:00
Kconfig.cpu
Kconfig.debug
Makefile
Makefile.um
Makefile_32.cpu