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 --- drivers/macintosh/macio_sysfs.c | 82 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 drivers/macintosh/macio_sysfs.c (limited to 'drivers/macintosh/macio_sysfs.c') diff --git a/drivers/macintosh/macio_sysfs.c b/drivers/macintosh/macio_sysfs.c new file mode 100644 index 000000000..2bbe359b2 --- /dev/null +++ b/drivers/macintosh/macio_sysfs.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include + +static ssize_t +compatible_show (struct device *dev, struct device_attribute *attr, char *buf) +{ + struct platform_device *of; + const char *compat; + int cplen; + int length = 0; + + of = &to_macio_device (dev)->ofdev; + compat = of_get_property(of->dev.of_node, "compatible", &cplen); + if (!compat) { + *buf = '\0'; + return 0; + } + while (cplen > 0) { + int l; + length += sprintf (buf, "%s\n", compat); + buf += length; + l = strlen (compat) + 1; + compat += l; + cplen -= l; + } + + return length; +} +static DEVICE_ATTR_RO(compatible); + +static ssize_t modalias_show (struct device *dev, struct device_attribute *attr, + char *buf) +{ + return of_device_modalias(dev, buf, PAGE_SIZE); +} + +static ssize_t devspec_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct platform_device *ofdev; + + ofdev = to_platform_device(dev); + return sprintf(buf, "%pOF\n", ofdev->dev.of_node); +} +static DEVICE_ATTR_RO(modalias); +static DEVICE_ATTR_RO(devspec); + +static ssize_t name_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%pOFn\n", dev->of_node); +} +static DEVICE_ATTR_RO(name); + +static ssize_t type_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%s\n", of_node_get_device_type(dev->of_node)); +} +static DEVICE_ATTR_RO(type); + +static struct attribute *macio_dev_attrs[] = { + &dev_attr_name.attr, + &dev_attr_type.attr, + &dev_attr_compatible.attr, + &dev_attr_modalias.attr, + &dev_attr_devspec.attr, + NULL, +}; + +static const struct attribute_group macio_dev_group = { + .attrs = macio_dev_attrs, +}; + +const struct attribute_group *macio_dev_groups[] = { + &macio_dev_group, + NULL, +}; -- cgit v1.3.1