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 --- security/apparmor/crypto.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 security/apparmor/crypto.c (limited to 'security/apparmor/crypto.c') diff --git a/security/apparmor/crypto.c b/security/apparmor/crypto.c new file mode 100644 index 000000000..d8a7bde94 --- /dev/null +++ b/security/apparmor/crypto.c @@ -0,0 +1,61 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor policy loading interface function definitions. + * + * Copyright 2013 Canonical Ltd. + * + * Fns to provide a checksum of policy that has been loaded this can be + * compared to userspace policy compiles to check loaded policy is what + * it should be. + */ + +#include + +#include "include/apparmor.h" +#include "include/crypto.h" + +unsigned int aa_hash_size(void) +{ + return SHA256_DIGEST_SIZE; +} + +char *aa_calc_hash(void *data, size_t len) +{ + char *hash; + + hash = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); + if (!hash) + return ERR_PTR(-ENOMEM); + + sha256(data, len, hash); + return hash; +} + +int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start, + size_t len) +{ + struct sha256_ctx sctx; + __le32 le32_version = cpu_to_le32(version); + + if (!aa_g_hash_policy) + return 0; + + profile->hash = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); + if (!profile->hash) + return -ENOMEM; + + sha256_init(&sctx); + sha256_update(&sctx, (u8 *)&le32_version, 4); + sha256_update(&sctx, (u8 *)start, len); + sha256_final(&sctx, profile->hash); + return 0; +} + +int __init init_profile_hash(void) +{ + if (apparmor_initialized) + aa_info_message("AppArmor sha256 policy hashing enabled"); + return 0; +} -- cgit v1.3.1