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/interconnect/bulk.c | 159 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 drivers/interconnect/bulk.c (limited to 'drivers/interconnect/bulk.c') diff --git a/drivers/interconnect/bulk.c b/drivers/interconnect/bulk.c new file mode 100644 index 000000000..8b1d8a412 --- /dev/null +++ b/drivers/interconnect/bulk.c @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include + +/** + * of_icc_bulk_get() - get interconnect paths + * @dev: the device requesting the path + * @num_paths: the number of icc_bulk_data + * @paths: the table with the paths we want to get + * + * Returns 0 on success or negative errno otherwise. + */ +int __must_check of_icc_bulk_get(struct device *dev, int num_paths, + struct icc_bulk_data *paths) +{ + int ret, i; + + for (i = 0; i < num_paths; i++) { + paths[i].path = of_icc_get(dev, paths[i].name); + if (IS_ERR(paths[i].path)) { + ret = PTR_ERR(paths[i].path); + if (ret != -EPROBE_DEFER) + dev_err(dev, "of_icc_get() failed on path %s (%d)\n", + paths[i].name, ret); + paths[i].path = NULL; + goto err; + } + } + + return 0; + +err: + icc_bulk_put(i, paths); + + return ret; +} +EXPORT_SYMBOL_GPL(of_icc_bulk_get); + +/** + * icc_bulk_put() - put a list of interconnect paths + * @num_paths: the number of icc_bulk_data + * @paths: the icc_bulk_data table with the paths being put + */ +void icc_bulk_put(int num_paths, struct icc_bulk_data *paths) +{ + while (--num_paths >= 0) { + icc_put(paths[num_paths].path); + paths[num_paths].path = NULL; + } +} +EXPORT_SYMBOL_GPL(icc_bulk_put); + +/** + * icc_bulk_set_bw() - set bandwidth to a set of paths + * @num_paths: the number of icc_bulk_data + * @paths: the icc_bulk_data table containing the paths and bandwidth + * + * Returns 0 on success or negative errno otherwise. + */ +int icc_bulk_set_bw(int num_paths, const struct icc_bulk_data *paths) +{ + int ret = 0; + int i; + + for (i = 0; i < num_paths; i++) { + ret = icc_set_bw(paths[i].path, paths[i].avg_bw, paths[i].peak_bw); + if (ret) { + pr_err("icc_set_bw() failed on path %s (%d)\n", paths[i].name, ret); + return ret; + } + } + + return ret; +} +EXPORT_SYMBOL_GPL(icc_bulk_set_bw); + +/** + * icc_bulk_enable() - enable a previously disabled set of paths + * @num_paths: the number of icc_bulk_data + * @paths: the icc_bulk_data table containing the paths and bandwidth + * + * Returns 0 on success or negative errno otherwise. + */ +int icc_bulk_enable(int num_paths, const struct icc_bulk_data *paths) +{ + int ret, i; + + for (i = 0; i < num_paths; i++) { + ret = icc_enable(paths[i].path); + if (ret) { + pr_err("icc_enable() failed on path %s (%d)\n", paths[i].name, ret); + goto err; + } + } + + return 0; + +err: + icc_bulk_disable(i, paths); + + return ret; +} +EXPORT_SYMBOL_GPL(icc_bulk_enable); + +/** + * icc_bulk_disable() - disable a set of interconnect paths + * @num_paths: the number of icc_bulk_data + * @paths: the icc_bulk_data table containing the paths and bandwidth + */ +void icc_bulk_disable(int num_paths, const struct icc_bulk_data *paths) +{ + while (--num_paths >= 0) + icc_disable(paths[num_paths].path); +} +EXPORT_SYMBOL_GPL(icc_bulk_disable); + +struct icc_bulk_devres { + struct icc_bulk_data *paths; + int num_paths; +}; + +static void devm_icc_bulk_release(struct device *dev, void *res) +{ + struct icc_bulk_devres *devres = res; + + icc_bulk_put(devres->num_paths, devres->paths); +} + +/** + * devm_of_icc_bulk_get() - resource managed of_icc_bulk_get + * @dev: the device requesting the path + * @num_paths: the number of icc_bulk_data + * @paths: the table with the paths we want to get + * + * Returns 0 on success or negative errno otherwise. + */ +int devm_of_icc_bulk_get(struct device *dev, int num_paths, struct icc_bulk_data *paths) +{ + struct icc_bulk_devres *devres; + int ret; + + devres = devres_alloc(devm_icc_bulk_release, sizeof(*devres), GFP_KERNEL); + if (!devres) + return -ENOMEM; + + ret = of_icc_bulk_get(dev, num_paths, paths); + if (!ret) { + devres->paths = paths; + devres->num_paths = num_paths; + devres_add(dev, devres); + } else { + devres_free(devres); + } + + return ret; +} +EXPORT_SYMBOL_GPL(devm_of_icc_bulk_get); -- cgit v1.3.1