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/rtc/rtc-ps3.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 drivers/rtc/rtc-ps3.c (limited to 'drivers/rtc/rtc-ps3.c') diff --git a/drivers/rtc/rtc-ps3.c b/drivers/rtc/rtc-ps3.c new file mode 100644 index 000000000..6b098734c --- /dev/null +++ b/drivers/rtc/rtc-ps3.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PS3 RTC Driver + * + * Copyright 2009 Sony Corporation + */ + +#include +#include +#include +#include + +#include +#include + + +static u64 read_rtc(void) +{ + int result; + u64 rtc_val; + u64 tb_val; + + result = lv1_get_rtc(&rtc_val, &tb_val); + BUG_ON(result); + + return rtc_val; +} + +static int ps3_get_time(struct device *dev, struct rtc_time *tm) +{ + rtc_time64_to_tm(read_rtc() + ps3_os_area_get_rtc_diff(), tm); + return 0; +} + +static int ps3_set_time(struct device *dev, struct rtc_time *tm) +{ + ps3_os_area_set_rtc_diff(rtc_tm_to_time64(tm) - read_rtc()); + return 0; +} + +static const struct rtc_class_ops ps3_rtc_ops = { + .read_time = ps3_get_time, + .set_time = ps3_set_time, +}; + +static int __init ps3_rtc_probe(struct platform_device *dev) +{ + struct rtc_device *rtc; + + rtc = devm_rtc_allocate_device(&dev->dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + rtc->ops = &ps3_rtc_ops; + rtc->range_max = U64_MAX; + + platform_set_drvdata(dev, rtc); + + return devm_rtc_register_device(rtc); +} + +static struct platform_driver ps3_rtc_driver = { + .driver = { + .name = "rtc-ps3", + }, +}; + +module_platform_driver_probe(ps3_rtc_driver, ps3_rtc_probe); + +MODULE_AUTHOR("Sony Corporation"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("ps3 RTC driver"); +MODULE_ALIAS("platform:rtc-ps3"); -- cgit v1.3.1