openrisc: fix arbitrary kernel memory access via or1k_atomic syscallgrafted

sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user
pointers, v1 and v2, and swaps the words they point to in hand-written
assembly.

    l.lwz   r29,0(r4)
    l.lwz   r27,0(r5)
    l.sw    0(r4),r27
    l.sw    0(r5),r29

The pointers are not checked with access_ok(). The four memory
accesses also have no exception table entries.

A caller passes a kernel address as either pointer, and the syscall
reads from and writes to it directly.

This gives an unprivileged process a kernel read/write primitive. It
overwrites kernel data such as the sys_call_table, gaining code
execution in kernel context.

Check both pointers before entering the critical section. Add fixups
for the four memory accesses so faults on valid but unmapped user
addresses return -EFAULT.

[shorne@gmail.com: fix comment style]
Fixes: 9d02a4283e9c ("OpenRISC: Boot code")
Cc: stable@vger.kernel.org
Signed-off-by: Ali Ahmet Memis <ali@iusegentoo.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/drivers/net/wireless/Kconfig b/drivers/net/wireless/Kconfig
new file mode 100644
index 000000000..c6599594d
--- /dev/null
+++ b/drivers/net/wireless/Kconfig
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Wireless LAN device configuration
+#
+
+menuconfig WLAN
+	bool "Wireless LAN"
+	depends on !S390
+	depends on NET
+	select WIRELESS
+	default y
+	help
+	  This section contains all the pre 802.11 and 802.11 wireless
+	  device drivers. For a complete list of drivers and documentation
+	  on them refer to the wireless wiki:
+
+	  https://wireless.wiki.kernel.org/en/users/Drivers
+
+if WLAN
+
+source "drivers/net/wireless/admtek/Kconfig"
+source "drivers/net/wireless/ath/Kconfig"
+source "drivers/net/wireless/atmel/Kconfig"
+source "drivers/net/wireless/broadcom/Kconfig"
+source "drivers/net/wireless/intel/Kconfig"
+source "drivers/net/wireless/intersil/Kconfig"
+source "drivers/net/wireless/marvell/Kconfig"
+source "drivers/net/wireless/mediatek/Kconfig"
+source "drivers/net/wireless/microchip/Kconfig"
+source "drivers/net/wireless/purelifi/Kconfig"
+source "drivers/net/wireless/ralink/Kconfig"
+source "drivers/net/wireless/realtek/Kconfig"
+source "drivers/net/wireless/rsi/Kconfig"
+source "drivers/net/wireless/silabs/Kconfig"
+source "drivers/net/wireless/st/Kconfig"
+source "drivers/net/wireless/ti/Kconfig"
+source "drivers/net/wireless/zydas/Kconfig"
+source "drivers/net/wireless/quantenna/Kconfig"
+
+source "drivers/net/wireless/virtual/Kconfig"
+
+endif # WLAN