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/delalloc-space.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 fs/btrfs/delalloc-space.h (limited to 'fs/btrfs/delalloc-space.h') diff --git a/fs/btrfs/delalloc-space.h b/fs/btrfs/delalloc-space.h new file mode 100644 index 000000000..6119c0d3f --- /dev/null +++ b/fs/btrfs/delalloc-space.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef BTRFS_DELALLOC_SPACE_H +#define BTRFS_DELALLOC_SPACE_H + +#include + +struct extent_changeset; +struct btrfs_inode; +struct btrfs_fs_info; + +int btrfs_alloc_data_chunk_ondemand(const struct btrfs_inode *inode, u64 bytes); +int btrfs_check_data_free_space(struct btrfs_inode *inode, + struct extent_changeset **reserved, u64 start, u64 len, + bool noflush); +void btrfs_free_reserved_data_space(struct btrfs_inode *inode, + struct extent_changeset *reserved, u64 start, u64 len); +void btrfs_delalloc_release_space(struct btrfs_inode *inode, + struct extent_changeset *reserved, + u64 start, u64 len, bool qgroup_free); +void btrfs_free_reserved_data_space_noquota(struct btrfs_inode *inode, u64 len); +void btrfs_delalloc_release_metadata(struct btrfs_inode *inode, u64 num_bytes, + bool qgroup_free); +int btrfs_delalloc_reserve_space(struct btrfs_inode *inode, + struct extent_changeset **reserved, u64 start, u64 len); +int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes, + u64 disk_num_bytes, bool noflush); +void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes); +void btrfs_delalloc_shrink_extents(struct btrfs_inode *inode, u64 reserved_len, u64 new_len); + +#endif /* BTRFS_DELALLOC_SPACE_H */ -- cgit v1.3.1