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/btrfs/root-tree.h | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 fs/btrfs/root-tree.h (limited to 'fs/btrfs/root-tree.h') diff --git a/fs/btrfs/root-tree.h b/fs/btrfs/root-tree.h new file mode 100644 index 000000000..8f5739e73 --- /dev/null +++ b/fs/btrfs/root-tree.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef BTRFS_ROOT_TREE_H +#define BTRFS_ROOT_TREE_H + +#include + +struct fscrypt_str; +struct extent_buffer; +struct btrfs_key; +struct btrfs_root; +struct btrfs_root_item; +struct btrfs_path; +struct btrfs_fs_info; +struct btrfs_block_rsv; +struct btrfs_trans_handle; + +int btrfs_subvolume_reserve_metadata(struct btrfs_root *root, + struct btrfs_block_rsv *rsv, + int nitems, bool use_global_rsv); +int btrfs_add_root_ref(struct btrfs_trans_handle *trans, u64 root_id, + u64 ref_id, u64 dirid, u64 sequence, + const struct fscrypt_str *name); +int btrfs_del_root_ref(struct btrfs_trans_handle *trans, u64 root_id, + u64 ref_id, u64 dirid, u64 *sequence, + const struct fscrypt_str *name); +int btrfs_del_root(struct btrfs_trans_handle *trans, const struct btrfs_key *key); +int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, + const struct btrfs_key *key, + struct btrfs_root_item *item); +int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, + struct btrfs_key *key, struct btrfs_root_item *item); +int btrfs_find_root(struct btrfs_root *root, const struct btrfs_key *search_key, + struct btrfs_path *path, struct btrfs_root_item *root_item, + struct btrfs_key *root_key); +int btrfs_find_orphan_roots(struct btrfs_fs_info *fs_info); +void btrfs_set_root_node(struct btrfs_root_item *item, + struct extent_buffer *node); +void btrfs_check_and_init_root_item(struct btrfs_root_item *item); +void btrfs_update_root_times(struct btrfs_trans_handle *trans, struct btrfs_root *root); + +#endif -- cgit v1.3.1