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 --- Documentation/ABI/testing/sysfs-class-switchtec | 96 +++++++++++++++++++++++++ 1 file changed, 96 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-switchtec (limited to 'Documentation/ABI/testing/sysfs-class-switchtec') diff --git a/Documentation/ABI/testing/sysfs-class-switchtec b/Documentation/ABI/testing/sysfs-class-switchtec new file mode 100644 index 000000000..76c7a661a --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-switchtec @@ -0,0 +1,96 @@ +switchtec - Microsemi Switchtec PCI Switch Management Endpoint + +For details on this subsystem look at Documentation/driver-api/switchtec.rst. + +What: /sys/class/switchtec +Date: 05-Jan-2017 +KernelVersion: v4.11 +Contact: Logan Gunthorpe +Description: The switchtec class subsystem folder. + Each registered switchtec driver is represented by a switchtecX + subfolder (X being an integer >= 0). + + +What: /sys/class/switchtec/switchtec[0-9]+/component_id +Date: 05-Jan-2017 +KernelVersion: v4.11 +Contact: Logan Gunthorpe +Description: Component identifier as stored in the hardware (eg. PM8543) + (read only) +Values: arbitrary string. + + +What: /sys/class/switchtec/switchtec[0-9]+/component_revision +Date: 05-Jan-2017 +KernelVersion: v4.11 +Contact: Logan Gunthorpe +Description: Component revision stored in the hardware (read only) +Values: integer. + + +What: /sys/class/switchtec/switchtec[0-9]+/component_vendor +Date: 05-Jan-2017 +KernelVersion: v4.11 +Contact: Logan Gunthorpe +Description: Component vendor as stored in the hardware (eg. MICROSEM) + (read only) +Values: arbitrary string. + + +What: /sys/class/switchtec/switchtec[0-9]+/device_version +Date: 05-Jan-2017 +KernelVersion: v4.11 +Contact: Logan Gunthorpe +Description: Device version as stored in the hardware (read only) +Values: integer. + + +What: /sys/class/switchtec/switchtec[0-9]+/fw_version +Date: 05-Jan-2017 +KernelVersion: v4.11 +Contact: Logan Gunthorpe +Description: Currently running firmware version (read only) +Values: integer (in hexadecimal). + + +What: /sys/class/switchtec/switchtec[0-9]+/partition +Date: 05-Jan-2017 +KernelVersion: v4.11 +Contact: Logan Gunthorpe +Description: Partition number for this device in the switch (read only) +Values: integer. + + +What: /sys/class/switchtec/switchtec[0-9]+/partition_count +Date: 05-Jan-2017 +KernelVersion: v4.11 +Contact: Logan Gunthorpe +Description: Total number of partitions in the switch (read only) +Values: integer. + + +What: /sys/class/switchtec/switchtec[0-9]+/product_id +Date: 05-Jan-2017 +KernelVersion: v4.11 +Contact: Logan Gunthorpe +Description: Product identifier as stored in the hardware (eg. PSX 48XG3) + (read only) +Values: arbitrary string. + + +What: /sys/class/switchtec/switchtec[0-9]+/product_revision +Date: 05-Jan-2017 +KernelVersion: v4.11 +Contact: Logan Gunthorpe +Description: Product revision stored in the hardware (eg. RevB) + (read only) +Values: arbitrary string. + + +What: /sys/class/switchtec/switchtec[0-9]+/product_vendor +Date: 05-Jan-2017 +KernelVersion: v4.11 +Contact: Logan Gunthorpe +Description: Product vendor as stored in the hardware (eg. MICROSEM) + (read only) +Values: arbitrary string. -- cgit v1.3.1