Patch "Fix potential infoleak in older kernels" has been added to the 4.4-stable tree

Patch "Fix potential infoleak in older kernels" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    Fix potential infoleak in older kernels

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     fix-potential-infoleak-in-older-kernels.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Tue Nov  8 11:17:00 CET 2016
Date: Tue, 08 Nov 2016 11:17:00 +0100
To: Greg KH <gregkh@linuxfoundation.org>
From: Linus Torvalds <torvalds@linux-foundation.org>
Subject: Fix potential infoleak in older kernels

From: Linus Torvalds <torvalds@linux-foundation.org>

Not upstream as it is not needed there.

So a patch something like this might be a safe way to fix the
potential infoleak in older kernels.

THIS IS UNTESTED. It's a very obvious patch, though, so if it compiles
it probably works. It just initializes the output variable with 0 in
the inline asm description, instead of doing it in the exception
handler.

It will generate slightly worse code (a few unnecessary ALU
operations), but it doesn't have any interactions with the exception
handler implementation.


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/include/asm/uaccess.h |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -332,7 +332,7 @@ do {									\
 #define __get_user_asm_u64(x, ptr, retval, errret) \
 	 __get_user_asm(x, ptr, retval, "q", "", "=r", errret)
 #define __get_user_asm_ex_u64(x, ptr) \
-	 __get_user_asm_ex(x, ptr, "q", "", "=r")
+	 __get_user_asm_ex(x, ptr, "q", "", "=&r")
 #endif
 
 #define __get_user_size(x, ptr, size, retval, errret)			\
@@ -375,13 +375,13 @@ do {									\
 	__chk_user_ptr(ptr);						\
 	switch (size) {							\
 	case 1:								\
-		__get_user_asm_ex(x, ptr, "b", "b", "=q");		\
+		__get_user_asm_ex(x, ptr, "b", "b", "=&q");		\
 		break;							\
 	case 2:								\
-		__get_user_asm_ex(x, ptr, "w", "w", "=r");		\
+		__get_user_asm_ex(x, ptr, "w", "w", "=&r");		\
 		break;							\
 	case 4:								\
-		__get_user_asm_ex(x, ptr, "l", "k", "=r");		\
+		__get_user_asm_ex(x, ptr, "l", "k", "=&r");		\
 		break;							\
 	case 8:								\
 		__get_user_asm_ex_u64(x, ptr);				\
@@ -395,7 +395,7 @@ do {									\
 	asm volatile("1:	mov"itype" %1,%"rtype"0\n"		\
 		     "2:\n"						\
 		     _ASM_EXTABLE_EX(1b, 2b)				\
-		     : ltype(x) : "m" (__m(addr)))
+		     : ltype(x) : "m" (__m(addr)), "0" (0))
 
 #define __put_user_nocheck(x, ptr, size)			\
 ({								\


Patches currently in stable-queue which might be from gregkh@linuxfoundation.org are

queue-4.4/ubifs-abort-readdir-upon-error.patch
queue-4.4/xhci-add-restart-quirk-for-intel-wildcatpoint-pch.patch
queue-4.4/alsa-hda-adding-a-new-group-of-pin-cfg-into-alc295-pin-quirk-table.patch
queue-4.4/dm-free-io_barrier-after-blk_cleanup_queue-call.patch
queue-4.4/tty-limit-terminal-size-to-4m-chars.patch
queue-4.4/mm-list_lru.c-avoid-error-path-null-pointer-deref.patch
queue-4.4/usb-gadget-function-u_ether-don-t-starve-tx-request-queue.patch
queue-4.4/ubifs-fix-regression-in-ubifs_readdir.patch
queue-4.4/alsa-hda-fix-headset-mic-detection-problem-for-two-dell-laptops.patch
queue-4.4/btrfs-fix-races-on-root_log_ctx-lists.patch
queue-4.4/usb-serial-cp210x-fix-tiocmget-error-handling.patch
queue-4.4/alsa-hda-merge-rirb_pre_delay-into-ctx_workaround-caps.patch
queue-4.4/i2c-imx-defer-probe-if-bus-recovery-gpios-are-not-ready.patch
queue-4.4/drm-dp-mst-clear-port-pdt-when-tearing-down-the-i2c-adapter.patch
queue-4.4/mm-memcontrol-do-not-recurse-in-direct-reclaim.patch
queue-4.4/usb-increase-ohci-watchdog-delay-to-275-msec.patch
queue-4.4/alsa-hda-allow-40-bit-dma-mask-for-nvidia-devices.patch
queue-4.4/vt-clear-selection-before-resizing.patch
queue-4.4/hv-do-not-lose-pending-heartbeat-vmbus-packets.patch
queue-4.4/usb-serial-ftdi_sio-add-support-for-infineon-triboard-tc2x7.patch
queue-4.4/i2c-core-fix-null-pointer-dereference-under-race-condition.patch
queue-4.4/mei-txe-don-t-clean-an-unprocessed-interrupt-cause.patch
queue-4.4/alsa-hda-raise-azx_dcaps_rirb_delay-handling-into-top-drivers.patch
queue-4.4/xhci-use-default-usb_resume_timeout-when-resuming-ports.patch
queue-4.4/i2c-xgene-avoid-dma_buffer-overrun.patch
queue-4.4/android-binder-add-strong-ref-checks.patch
queue-4.4/h8300-fix-syscall-restarting.patch
queue-4.4/fix-potential-infoleak-in-older-kernels.patch
queue-4.4/libxfs-clean-up-_calc_dquots_per_chunk.patch
queue-4.4/keys-fix-short-sprintf-buffer-in-proc-keys-show-function.patch
queue-4.4/android-binder-clear-binder-and-cookie-when-setting-handle-in-flat-binder-struct.patch
queue-4.4/genwqe-fix-bad-page-access-during-abort-of-resource-allocation.patch
queue-4.4/usb-serial-fix-potential-null-dereference-at-probe.patch
queue-4.4/alsa-usb-audio-add-quirk-for-syntek-stk1160.patch