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 --- fs/ocfs2/localalloc.h | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 fs/ocfs2/localalloc.h (limited to 'fs/ocfs2/localalloc.h') diff --git a/fs/ocfs2/localalloc.h b/fs/ocfs2/localalloc.h new file mode 100644 index 000000000..08f925b7e --- /dev/null +++ b/fs/ocfs2/localalloc.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * localalloc.h + * + * Function prototypes + * + * Copyright (C) 2002, 2004 Oracle. All rights reserved. + */ + +#ifndef OCFS2_LOCALALLOC_H +#define OCFS2_LOCALALLOC_H + +int ocfs2_load_local_alloc(struct ocfs2_super *osb); + +void ocfs2_shutdown_local_alloc(struct ocfs2_super *osb); + +void ocfs2_la_set_sizes(struct ocfs2_super *osb, int requested_mb); +unsigned int ocfs2_la_default_mb(struct ocfs2_super *osb); + +int ocfs2_begin_local_alloc_recovery(struct ocfs2_super *osb, + int node_num, + struct ocfs2_dinode **alloc_copy); + +int ocfs2_complete_local_alloc_recovery(struct ocfs2_super *osb, + struct ocfs2_dinode *alloc); + +int ocfs2_alloc_should_use_local(struct ocfs2_super *osb, + u64 bits); + +struct ocfs2_alloc_context; +int ocfs2_reserve_local_alloc_bits(struct ocfs2_super *osb, + u32 bits_wanted, + struct ocfs2_alloc_context *ac); + +int ocfs2_claim_local_alloc_bits(struct ocfs2_super *osb, + handle_t *handle, + struct ocfs2_alloc_context *ac, + u32 bits_wanted, + u32 *bit_off, + u32 *num_bits); + +int ocfs2_free_local_alloc_bits(struct ocfs2_super *osb, + handle_t *handle, + struct ocfs2_alloc_context *ac, + u32 bit_off, + u32 num_bits); + +void ocfs2_local_alloc_seen_free_bits(struct ocfs2_super *osb, + unsigned int num_clusters); +void ocfs2_la_enable_worker(struct work_struct *work); + +#endif /* OCFS2_LOCALALLOC_H */ -- cgit v1.3.1