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/landlock/audit.h | 76 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 security/landlock/audit.h (limited to 'security/landlock/audit.h') diff --git a/security/landlock/audit.h b/security/landlock/audit.h new file mode 100644 index 000000000..620f8a242 --- /dev/null +++ b/security/landlock/audit.h @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock - Audit helpers + * + * Copyright © 2023-2025 Microsoft Corporation + */ + +#ifndef _SECURITY_LANDLOCK_AUDIT_H +#define _SECURITY_LANDLOCK_AUDIT_H + +#include +#include + +#include "access.h" +#include "cred.h" + +enum landlock_request_type { + LANDLOCK_REQUEST_PTRACE = 1, + LANDLOCK_REQUEST_FS_CHANGE_TOPOLOGY, + LANDLOCK_REQUEST_FS_ACCESS, + LANDLOCK_REQUEST_NET_ACCESS, + LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET, + LANDLOCK_REQUEST_SCOPE_SIGNAL, +}; + +/* + * We should be careful to only use a variable of this type for + * landlock_log_denial(). This way, the compiler can remove it entirely if + * CONFIG_AUDIT is not set. + */ +struct landlock_request { + /* Mandatory fields. */ + enum landlock_request_type type; + struct common_audit_data audit; + + /** + * layer_plus_one: First layer level that denies the request + 1. The + * extra one is useful to detect uninitialized field. + */ + size_t layer_plus_one; + + /* Required field for configurable access control. */ + access_mask_t access; + + /* Required fields for requests with layer masks. */ + const struct layer_masks *layer_masks; + + /* Required fields for requests with deny masks. */ + const access_mask_t all_existing_optional_access; + deny_masks_t deny_masks; + optional_access_t quiet_optional_accesses; +}; + +#ifdef CONFIG_AUDIT + +void landlock_log_drop_domain(const struct landlock_hierarchy *const hierarchy); + +void landlock_log_denial(const struct landlock_cred_security *const subject, + const struct landlock_request *const request); + +#else /* CONFIG_AUDIT */ + +static inline void +landlock_log_drop_domain(const struct landlock_hierarchy *const hierarchy) +{ +} + +static inline void +landlock_log_denial(const struct landlock_cred_security *const subject, + const struct landlock_request *const request) +{ +} + +#endif /* CONFIG_AUDIT */ + +#endif /* _SECURITY_LANDLOCK_AUDIT_H */ -- cgit v1.3.1