From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall 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 Signed-off-by: Stafford Horne --- .../ABI/testing/sysfs-driver-input-exc3000 | 26 ++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-driver-input-exc3000 (limited to 'Documentation/ABI/testing/sysfs-driver-input-exc3000') diff --git a/Documentation/ABI/testing/sysfs-driver-input-exc3000 b/Documentation/ABI/testing/sysfs-driver-input-exc3000 new file mode 100644 index 000000000..704434b27 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-driver-input-exc3000 @@ -0,0 +1,26 @@ +What: /sys/bus/i2c/devices/xxx/fw_version +Date: Aug 2020 +Contact: linux-input@vger.kernel.org +Description: Reports the firmware version provided by the touchscreen, for example "00_T6" on a EXC80H60 + + Access: Read + + Valid values: Represented as string + +What: /sys/bus/i2c/devices/xxx/model +Date: Aug 2020 +Contact: linux-input@vger.kernel.org +Description: Reports the model identification provided by the touchscreen, for example "Orion_1320" on a EXC80H60 + + Access: Read + + Valid values: Represented as string + +What: /sys/bus/i2c/devices/xxx/type +Date: Jan 2021 +Contact: linux-input@vger.kernel.org +Description: Reports the type identification provided by the touchscreen, for example "PCAP82H80 Series" + + Access: Read + + Valid values: Represented as string -- cgit v1.3.1