Merge 4.4.236 into android-4.4-p

Changes in 4.4.236
	HID: core: Correctly handle ReportSize being zero
	HID: core: Sanitize event code and type when mapping input
	perf record/stat: Explicitly call out event modifiers in the documentation
	mm, page_alloc: remove unnecessary variable from free_pcppages_bulk
	hwmon: (applesmc) check status earlier.
	ceph: don't allow setlease on cephfs
	s390: don't trace preemption in percpu macros
	xen/xenbus: Fix granting of vmalloc'd memory
	dmaengine: of-dma: Fix of_dma_router_xlate's of_dma_xlate handling
	batman-adv: Avoid uninitialized chaddr when handling DHCP
	batman-adv: bla: use netif_rx_ni when not in interrupt context
	dmaengine: at_hdmac: check return value of of_find_device_by_node() in at_dma_xlate()
	netfilter: nf_tables: incorrect enum nft_list_attributes definition
	netfilter: nf_tables: fix destination register zeroing
	dmaengine: pl330: Fix burst length if burst size is smaller than bus width
	bnxt_en: Check for zero dir entries in NVRAM.
	fix regression in "epoll: Keep a reference on files added to the check list"
	tg3: Fix soft lockup when tg3_reset_task() fails.
	iommu/vt-d: Serialize IOMMU GCMD register modifications
	thermal: ti-soc-thermal: Fix bogus thermal shutdowns for omap4430
	include/linux/log2.h: add missing () around n in roundup_pow_of_two()
	btrfs: drop path before adding new uuid tree entry
	btrfs: Remove redundant extent_buffer_get in get_old_root
	btrfs: Remove extraneous extent_buffer_get from tree_mod_log_rewind
	btrfs: set the lockdep class for log tree extent buffers
	uaccess: Add non-pagefault user-space read functions
	uaccess: Add non-pagefault user-space write function
	btrfs: fix potential deadlock in the search ioctl
	net: qmi_wwan: MDM9x30 specific power management
	net: qmi_wwan: support "raw IP" mode
	net: qmi_wwan: should hold RTNL while changing netdev type
	net: qmi_wwan: ignore bogus CDC Union descriptors
	Add Dell Wireless 5809e Gobi 4G HSPA+ Mobile Broadband Card (rev3) to qmi_wwan
	qmi_wwan: Added support for Gemalto's Cinterion PHxx WWAN interface
	qmi_wwan: add support for Quectel EC21 and EC25
	NET: usb: qmi_wwan: add support for Telit LE922A PID 0x1040
	drivers: net: usb: qmi_wwan: add QMI_QUIRK_SET_DTR for Telit PID 0x1201
	usb: qmi_wwan: add D-Link DWM-222 A2 device ID
	net: usb: qmi_wwan: add Telit ME910 support
	net: usb: qmi_wwan: add Telit 0x1050 composition
	ALSA: ca0106: fix error code handling
	ALSA: pcm: oss: Remove superfluous WARN_ON() for mulaw sanity check
	dm cache metadata: Avoid returning cmd->bm wild pointer on error
	dm thin metadata: Avoid returning cmd->bm wild pointer on error
	net: refactor bind_bucket fastreuse into helper
	net: initialize fastreuse on inet_inherit_port
	checkpatch: fix the usage of capture group ( ... )
	mm/hugetlb: fix a race between hugetlb sysctl handlers
	cfg80211: regulatory: reject invalid hints
	net: usb: Fix uninit-was-stored issue in asix_read_phy_addr()
	ALSA: firewire-digi00x: add support for console models of Digi00x series
	ALSA: firewire-digi00x: exclude Avid Adrenaline from detection
	ALSA; firewire-tascam: exclude Tascam FE-8 from detection
	fs/affs: use octal for permissions
	affs: fix basic permission bits to actually work
	ravb: Fixed to be able to unload modules
	net: ethernet: mlx4: Fix memory allocation in mlx4_buddy_init()
	bnxt_en: Failure to update PHY is not fatal condition.
	bnxt: don't enable NAPI until rings are ready
	net: usb: dm9601: Add USB ID of Keenetic Plus DSL
	sctp: not disable bh in the whole sctp_get_port_local()
	net: disable netpoll on fresh napis
	Linux 4.4.236

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I45da24ccdf864c8774a1265a5d81685e04add060

1 files changed, 157 insertions, 10 deletions

diff --git a/mm/maccess.c b/mm/maccess.c
index d159b1c96e48..18717e893a75 100644
--- a/mm/maccess.c
+++ b/mm/maccess.c
@@ -5,8 +5,32 @@
 #include <linux/mm.h>
 #include <linux/uaccess.h>
 
+static __always_inline long
+probe_read_common(void *dst, const void __user *src, size_t size)
+{
+	long ret;
+
+	pagefault_disable();
+	ret = __copy_from_user_inatomic(dst, src, size);
+	pagefault_enable();
+
+	return ret ? -EFAULT : 0;
+}
+
+static __always_inline long
+probe_write_common(void __user *dst, const void *src, size_t size)
+{
+	long ret;
+
+	pagefault_disable();
+	ret = __copy_to_user_inatomic(dst, src, size);
+	pagefault_enable();
+
+	return ret ? -EFAULT : 0;
+}
+
 /**
- * probe_kernel_read(): safely attempt to read from a location
+ * probe_kernel_read(): safely attempt to read from a kernel-space location
  * @dst: pointer to the buffer that shall take the data
  * @src: address to read from
  * @size: size of the data chunk
@@ -29,17 +53,41 @@ long __probe_kernel_read(void *dst, const void *src, size_t size)
 	mm_segment_t old_fs = get_fs();
 
 	set_fs(KERNEL_DS);
-	pagefault_disable();
-	ret = __copy_from_user_inatomic(dst,
-			(__force const void __user *)src, size);
-	pagefault_enable();
+	ret = probe_read_common(dst, (__force const void __user *)src, size);
 	set_fs(old_fs);
 
-	return ret ? -EFAULT : 0;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(probe_kernel_read);
 
 /**
+ * probe_user_read(): safely attempt to read from a user-space location
+ * @dst: pointer to the buffer that shall take the data
+ * @src: address to read from. This must be a user address.
+ * @size: size of the data chunk
+ *
+ * Safely read from user address @src to the buffer at @dst. If a kernel fault
+ * happens, handle that and return -EFAULT.
+ */
+
+long __weak probe_user_read(void *dst, const void __user *src, size_t size)
+    __attribute__((alias("__probe_user_read")));
+
+long __probe_user_read(void *dst, const void __user *src, size_t size)
+{
+	long ret = -EFAULT;
+	mm_segment_t old_fs = get_fs();
+
+	set_fs(USER_DS);
+	if (access_ok(VERIFY_READ, src, size))
+		ret = probe_read_common(dst, src, size);
+	set_fs(old_fs);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(probe_user_read);
+
+/**
  * probe_kernel_write(): safely attempt to write to a location
  * @dst: address to write to
  * @src: pointer to the data that shall be written
@@ -48,6 +96,7 @@ EXPORT_SYMBOL_GPL(probe_kernel_read);
  * Safely write to address @dst from the buffer at @src.  If a kernel fault
  * happens, handle that and return -EFAULT.
  */
+
 long __weak probe_kernel_write(void *dst, const void *src, size_t size)
     __attribute__((alias("__probe_kernel_write")));
 
@@ -57,16 +106,41 @@ long __probe_kernel_write(void *dst, const void *src, size_t size)
 	mm_segment_t old_fs = get_fs();
 
 	set_fs(KERNEL_DS);
-	pagefault_disable();
-	ret = __copy_to_user_inatomic((__force void __user *)dst, src, size);
-	pagefault_enable();
+	ret = probe_write_common((__force void __user *)dst, src, size);
 	set_fs(old_fs);
 
-	return ret ? -EFAULT : 0;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(probe_kernel_write);
 
 /**
+ * probe_user_write(): safely attempt to write to a user-space location
+ * @dst: address to write to
+ * @src: pointer to the data that shall be written
+ * @size: size of the data chunk
+ *
+ * Safely write to address @dst from the buffer at @src.  If a kernel fault
+ * happens, handle that and return -EFAULT.
+ */
+
+long __weak probe_user_write(void __user *dst, const void *src, size_t size)
+    __attribute__((alias("__probe_user_write")));
+
+long __probe_user_write(void __user *dst, const void *src, size_t size)
+{
+	long ret = -EFAULT;
+	mm_segment_t old_fs = get_fs();
+
+	set_fs(USER_DS);
+	if (access_ok(VERIFY_WRITE, dst, size))
+		ret = probe_write_common(dst, src, size);
+	set_fs(old_fs);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(probe_user_write);
+
+/**
  * strncpy_from_unsafe: - Copy a NUL terminated string from unsafe address.
  * @dst:   Destination address, in kernel space.  This buffer must be at
  *         least @count bytes long.
@@ -106,3 +180,76 @@ long strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count)
 
 	return ret ? -EFAULT : src - unsafe_addr;
 }
+
+/**
+ * strncpy_from_unsafe_user: - Copy a NUL terminated string from unsafe user
+ *				address.
+ * @dst:   Destination address, in kernel space.  This buffer must be at
+ *         least @count bytes long.
+ * @unsafe_addr: Unsafe user address.
+ * @count: Maximum number of bytes to copy, including the trailing NUL.
+ *
+ * Copies a NUL-terminated string from unsafe user address to kernel buffer.
+ *
+ * On success, returns the length of the string INCLUDING the trailing NUL.
+ *
+ * If access fails, returns -EFAULT (some data may have been copied
+ * and the trailing NUL added).
+ *
+ * If @count is smaller than the length of the string, copies @count-1 bytes,
+ * sets the last byte of @dst buffer to NUL and returns @count.
+ */
+long strncpy_from_unsafe_user(char *dst, const void __user *unsafe_addr,
+			      long count)
+{
+	mm_segment_t old_fs = get_fs();
+	long ret;
+
+	if (unlikely(count <= 0))
+		return 0;
+
+	set_fs(USER_DS);
+	pagefault_disable();
+	ret = strncpy_from_user(dst, unsafe_addr, count);
+	pagefault_enable();
+	set_fs(old_fs);
+
+	if (ret >= count) {
+		ret = count;
+		dst[ret - 1] = '\0';
+	} else if (ret > 0) {
+		ret++;
+	}
+
+	return ret;
+}
+
+/**
+ * strnlen_unsafe_user: - Get the size of a user string INCLUDING final NUL.
+ * @unsafe_addr: The string to measure.
+ * @count: Maximum count (including NUL)
+ *
+ * Get the size of a NUL-terminated string in user space without pagefault.
+ *
+ * Returns the size of the string INCLUDING the terminating NUL.
+ *
+ * If the string is too long, returns a number larger than @count. User
+ * has to check the return value against "> count".
+ * On exception (or invalid count), returns 0.
+ *
+ * Unlike strnlen_user, this can be used from IRQ handler etc. because
+ * it disables pagefaults.
+ */
+long strnlen_unsafe_user(const void __user *unsafe_addr, long count)
+{
+	mm_segment_t old_fs = get_fs();
+	int ret;
+
+	set_fs(USER_DS);
+	pagefault_disable();
+	ret = strnlen_user(unsafe_addr, count);
+	pagefault_enable();
+	set_fs(old_fs);
+
+	return ret;
+}