linux/arch
Andy Lutomirski 3fb2f4237b x86/tls: Don't validate lm in set_thread_area() after all
It turns out that there's a lurking ABI issue.  GCC, when
compiling this in a 32-bit program:

struct user_desc desc = {
	.entry_number    = idx,
	.base_addr       = base,
	.limit           = 0xfffff,
	.seg_32bit       = 1,
	.contents        = 0, /* Data, grow-up */
	.read_exec_only  = 0,
	.limit_in_pages  = 1,
	.seg_not_present = 0,
	.useable         = 0,
};

will leave .lm uninitialized.  This means that anything in the
kernel that reads user_desc.lm for 32-bit tasks is unreliable.

Revert the .lm check in set_thread_area().  The value never did
anything in the first place.

Fixes: 0e58af4e1d ("x86/tls: Disallow unusual TLS segments")
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org # Only if 0e58af4e1d is backported
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/d7875b60e28c512f6a6fc0baf5714d58e7eaadbb.1418856405.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-12-18 12:12:26 +01:00
..
alpha
arc
arm ARM: SoC fixes for 3.18-rc5 2014-11-16 16:21:57 -08:00
arm64 arm64 fixes: 2014-11-14 14:24:33 -08:00
avr32
blackfin
c6x
cris
frv
hexagon
ia64
m32r
m68k m68k: Wire up bpf 2014-10-27 11:02:19 +01:00
metag
microblaze microblaze: Wire up bpf syscall 2014-10-27 09:25:34 +01:00
mips MIPS: jump_label.c: Handle the microMIPS J instruction encoding 2014-11-19 18:22:09 +01:00
mn10300
openrisc
parisc parisc: Avoid using CONFIG_64BIT in userspace exported headers 2014-11-10 22:25:29 +01:00
powerpc powerpc/fsl_msi: mark the msi cascade handler IRQF_NO_THREAD 2014-11-17 22:00:30 -06:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2014-11-05 12:13:52 -08:00
score
sh sh: fix sh770x SCIF memory regions 2014-10-29 16:33:15 -07:00
sparc sparc64: Fix constraints on swab helpers. 2014-11-16 13:19:32 -08:00
tile
um
unicore32
x86 x86/tls: Don't validate lm in set_thread_area() after all 2014-12-18 12:12:26 +01:00
xtensa
.gitignore
Kconfig