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/PCI/controller/index.rst | 10 +++++++ .../PCI/controller/rcar-pcie-firmware.rst | 32 ++++++++++++++++++++++ 2 files changed, 42 insertions(+) create mode 100644 Documentation/PCI/controller/index.rst create mode 100644 Documentation/PCI/controller/rcar-pcie-firmware.rst (limited to 'Documentation/PCI/controller') diff --git a/Documentation/PCI/controller/index.rst b/Documentation/PCI/controller/index.rst new file mode 100644 index 000000000..c2ce9ccdc --- /dev/null +++ b/Documentation/PCI/controller/index.rst @@ -0,0 +1,10 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=========================================== +PCI Native Host Bridge and Endpoint Drivers +=========================================== + +.. toctree:: + :maxdepth: 2 + + rcar-pcie-firmware diff --git a/Documentation/PCI/controller/rcar-pcie-firmware.rst b/Documentation/PCI/controller/rcar-pcie-firmware.rst new file mode 100644 index 000000000..67d3bf66e --- /dev/null +++ b/Documentation/PCI/controller/rcar-pcie-firmware.rst @@ -0,0 +1,32 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================================================= +Firmware of PCIe controller for Renesas R-Car V4H +================================================= + +Renesas R-Car V4H (r8a779g0) has a PCIe controller, requiring a specific +firmware download during startup. + +However, Renesas currently cannot distribute the firmware free of charge. + +The firmware file "104_PCIe_fw_addr_data_ver1.05.txt" (note that the file name +might be different between different datasheet revisions) can be found in the +datasheet encoded as text, and as such, the file's content must be converted +back to binary form. This can be achieved using the following example script: + +.. code-block:: sh + + $ awk '/^\s*0x[0-9A-Fa-f]{4}\s+0x[0-9A-Fa-f]{4}/ { print substr($2,5,2) substr($2,3,2) }' \ + 104_PCIe_fw_addr_data_ver1.05.txt | \ + xxd -p -r > rcar_gen4_pcie.bin + +Once the text content has been converted into a binary firmware file, verify +its checksum as follows: + +.. code-block:: sh + + $ sha1sum rcar_gen4_pcie.bin + 1d0bd4b189b4eb009f5d564b1f93a79112994945 rcar_gen4_pcie.bin + +The resulting binary file called "rcar_gen4_pcie.bin" should be placed in the +"/lib/firmware" directory before the driver runs. -- cgit v1.3.1