linux/arch/x86/ia32
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
..
audit.c x86: coding style fixes in arch/x86/ia32/audit.c 2008-01-30 13:32:54 +01:00
ia32_aout.c handle suicide on late failure exits in execve() in search_binary_handler() 2014-10-09 02:39:00 -04:00
ia32_signal.c x86, vdso: Reimplement vdso.so preparation in build-time C 2014-05-05 13:18:51 -07:00
ia32entry.S x86_64, entry: Fix out of bounds read on sysenter 2014-10-31 18:47:09 -07:00
Makefile merge compat sys_ipc instances 2013-03-03 23:00:27 -05:00
nosyscall.c x86-64, ia32: Move compat_ni_syscall into C and its own file 2011-11-17 13:35:35 -08:00
sys_ia32.c unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE 2013-05-09 13:46:38 -04:00
syscall_ia32.c x86, syscall: Re-fix typo in comment 2011-11-18 16:25:07 -08:00