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 --- crypto/fips.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 crypto/fips.c (limited to 'crypto/fips.c') diff --git a/crypto/fips.c b/crypto/fips.c new file mode 100644 index 000000000..c59711248 --- /dev/null +++ b/crypto/fips.c @@ -0,0 +1,102 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * FIPS 200 support. + * + * Copyright (c) 2008 Neil Horman + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +int fips_enabled; +EXPORT_SYMBOL_GPL(fips_enabled); + +ATOMIC_NOTIFIER_HEAD(fips_fail_notif_chain); +EXPORT_SYMBOL_GPL(fips_fail_notif_chain); + +/* Process kernel command-line parameter at boot time. fips=0 or fips=1 */ +static int __init fips_enable(char *str) +{ + if (kstrtoint(str, 0, &fips_enabled)) + return 0; + + fips_enabled = !!fips_enabled; + pr_info("fips mode: %s\n", str_enabled_disabled(fips_enabled)); + return 1; +} + +__setup("fips=", fips_enable); + +#define FIPS_MODULE_NAME CONFIG_CRYPTO_FIPS_NAME +#ifdef CONFIG_CRYPTO_FIPS_CUSTOM_VERSION +#define FIPS_MODULE_VERSION CONFIG_CRYPTO_FIPS_VERSION +#else +#define FIPS_MODULE_VERSION UTS_RELEASE +#endif + +static char fips_name[] = FIPS_MODULE_NAME; +static char fips_version[] = FIPS_MODULE_VERSION; + +static const struct ctl_table crypto_sysctl_table[] = { + { + .procname = "fips_enabled", + .data = &fips_enabled, + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = proc_dointvec + }, + { + .procname = "fips_name", + .data = &fips_name, + .maxlen = 64, + .mode = 0444, + .proc_handler = proc_dostring + }, + { + .procname = "fips_version", + .data = &fips_version, + .maxlen = 64, + .mode = 0444, + .proc_handler = proc_dostring + }, +}; + +static struct ctl_table_header *crypto_sysctls; + +static void crypto_proc_fips_init(void) +{ + crypto_sysctls = register_sysctl("crypto", crypto_sysctl_table); +} + +static void crypto_proc_fips_exit(void) +{ + unregister_sysctl_table(crypto_sysctls); +} + +void fips_fail_notify(void) +{ + if (fips_enabled) + atomic_notifier_call_chain(&fips_fail_notif_chain, 0, NULL); +} +EXPORT_SYMBOL_GPL(fips_fail_notify); + +static int __init fips_init(void) +{ + crypto_proc_fips_init(); + return 0; +} + +static void __exit fips_exit(void) +{ + crypto_proc_fips_exit(); +} + +module_init(fips_init); +module_exit(fips_exit); -- cgit v1.3.1