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/driver-api/index.rst | 151 +++++++++++++++++++++++++++++++++++++ 1 file changed, 151 insertions(+) create mode 100644 Documentation/driver-api/index.rst (limited to 'Documentation/driver-api/index.rst') diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst new file mode 100644 index 000000000..eaf7161ff --- /dev/null +++ b/Documentation/driver-api/index.rst @@ -0,0 +1,151 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================== +Driver implementer's API guide +============================== + +The kernel offers a wide variety of interfaces to support the development +of device drivers. This document is an only somewhat organized collection +of some of those interfaces — it will hopefully get better over time! The +available subsections can be seen below. + + +General information for driver authors +====================================== + +This section contains documentation that should, at some point or other, be +of interest to most developers working on device drivers. + +.. toctree:: + :maxdepth: 1 + + basics + driver-model/index + device_link + infrastructure + ioctl + pm/index + +Useful support libraries +======================== + +This section contains documentation that should, at some point or other, be +of interest to most developers working on device drivers. + +.. toctree:: + :maxdepth: 1 + + early-userspace/index + connector + device-io + devfreq + dma-buf + component + io-mapping + io_ordering + uio-howto + vfio-mediated-device + vfio + vfio-pci-device-specific-driver-acceptance + +Bus-level documentation +======================= + +.. toctree:: + :maxdepth: 1 + + auxiliary_bus + cxl/index + eisa + firewire + i3c/index + isa + men-chameleon-bus + pci/index + rapidio/index + slimbus + usb/index + virtio/index + vme + w1 + xillybus + + +Subsystem-specific APIs +======================= + +.. toctree:: + :maxdepth: 1 + + 80211/index + acpi/index + backlight/lp855x-driver.rst + clk + coco/index + console + crypto/index + dmaengine/index + dpll + edac + extcon + firmware/index + fpga/index + frame-buffer + aperture + generic-counter + generic_pt + gpio/index + hsi + hte/index + hw-recoverable-errors + i2c + iio/index + infiniband + input + interconnect + ipmb + ipmi + libata + mailbox + md/index + media/index + mei/index + memory-devices/index + message-based + misc_devices + miscellaneous + mmc/index + mtd/index + mtdnand + nfc/index + ntb + nvdimm/index + nvmem + parport-lowlevel + phy/index + pin-control + pldmfw/index + pps + ptp + pwm + pwrseq + regulator + reset + rfkill + s390-drivers + scsi + serial/index + sm501 + soundwire/index + spi + surface_aggregator/index + switchtec + sync_file + target + tee + thermal/index + tty/index + wbrf + wmi + xilinx/index + zorro -- cgit v1.3.1