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/file.h | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 fs/btrfs/file.h (limited to 'fs/btrfs/file.h') diff --git a/fs/btrfs/file.h b/fs/btrfs/file.h new file mode 100644 index 000000000..d7df81388 --- /dev/null +++ b/fs/btrfs/file.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef BTRFS_FILE_H +#define BTRFS_FILE_H + +#include + +struct file; +struct extent_state; +struct kiocb; +struct iov_iter; +struct inode; +struct folio; +struct page; +struct btrfs_ioctl_encoded_io_args; +struct btrfs_drop_extents_args; +struct btrfs_inode; +struct btrfs_root; +struct btrfs_path; +struct btrfs_replace_extent_info; +struct btrfs_trans_handle; + +extern const struct file_operations btrfs_file_operations; + +int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync); +int btrfs_drop_extents(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct btrfs_inode *inode, + struct btrfs_drop_extents_args *args); +int btrfs_replace_file_extents(struct btrfs_inode *inode, + struct btrfs_path *path, const u64 start, + const u64 end, + struct btrfs_replace_extent_info *extent_info, + struct btrfs_trans_handle **trans_out); +int btrfs_mark_extent_written(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, u64 start, u64 end); +ssize_t btrfs_do_write_iter(struct kiocb *iocb, struct iov_iter *from, + const struct btrfs_ioctl_encoded_io_args *encoded); +int btrfs_release_file(struct inode *inode, struct file *file); +int btrfs_dirty_folio(struct btrfs_inode *inode, struct folio *folio, loff_t pos, + size_t write_bytes, struct extent_state **cached, bool noreserve); +int btrfs_fdatawrite_range(struct btrfs_inode *inode, loff_t start, loff_t end); +int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos, + size_t *write_bytes, bool nowait); +void btrfs_check_nocow_unlock(struct btrfs_inode *inode); +bool btrfs_find_delalloc_in_range(struct btrfs_inode *inode, u64 start, u64 end, + struct extent_state **cached_state, + u64 *delalloc_start_ret, u64 *delalloc_end_ret); +int btrfs_write_check(struct kiocb *iocb, size_t count); +ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i); + +#endif -- cgit v1.3.1