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/relocation.h | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 fs/btrfs/relocation.h (limited to 'fs/btrfs/relocation.h') diff --git a/fs/btrfs/relocation.h b/fs/btrfs/relocation.h new file mode 100644 index 000000000..bb7a86e7d --- /dev/null +++ b/fs/btrfs/relocation.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef BTRFS_RELOCATION_H +#define BTRFS_RELOCATION_H + +#include + +struct extent_buffer; +struct btrfs_fs_info; +struct btrfs_root; +struct btrfs_trans_handle; +struct btrfs_ordered_extent; +struct btrfs_pending_snapshot; + +static inline bool should_relocate_using_remap_tree(const struct btrfs_block_group *bg) +{ + if (!btrfs_fs_incompat(bg->fs_info, REMAP_TREE)) + return false; + + if (bg->flags & (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA_REMAP)) + return false; + + return true; +} + +int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start, + bool verbose); +int btrfs_init_reloc_root(struct btrfs_trans_handle *trans, struct btrfs_root *root); +int btrfs_update_reloc_root(struct btrfs_trans_handle *trans, + struct btrfs_root *root); +int btrfs_recover_relocation(struct btrfs_fs_info *fs_info); +int btrfs_reloc_clone_csums(struct btrfs_ordered_extent *ordered); +int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + const struct extent_buffer *buf, + struct extent_buffer *cow); +void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending, + u64 *bytes_to_reserve); +int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans, + struct btrfs_pending_snapshot *pending); +int btrfs_should_cancel_balance(const struct btrfs_fs_info *fs_info); +struct btrfs_root *find_reloc_root(struct btrfs_fs_info *fs_info, u64 bytenr); +bool btrfs_should_ignore_reloc_root(const struct btrfs_root *root); +u64 btrfs_get_reloc_bg_bytenr(struct btrfs_fs_info *fs_info); +int btrfs_translate_remap(struct btrfs_fs_info *fs_info, u64 *logical, u64 *length); +int btrfs_remove_extent_from_remap_tree(struct btrfs_trans_handle *trans, + struct btrfs_path *path, + u64 bytenr, u64 num_bytes); +int btrfs_last_identity_remap_gone(struct btrfs_chunk_map *chunk_map, + struct btrfs_block_group *bg); + +#endif -- cgit v1.3.1