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/sysfs.h | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 fs/btrfs/sysfs.h (limited to 'fs/btrfs/sysfs.h') diff --git a/fs/btrfs/sysfs.h b/fs/btrfs/sysfs.h new file mode 100644 index 000000000..05498e534 --- /dev/null +++ b/fs/btrfs/sysfs.h @@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef BTRFS_SYSFS_H +#define BTRFS_SYSFS_H + +#include +#include +#include + +struct block_device; +struct btrfs_fs_info; +struct btrfs_device; +struct btrfs_fs_devices; +struct btrfs_block_group; +struct btrfs_space_info; +struct btrfs_qgroup; + +enum btrfs_feature_set { + FEAT_COMPAT, + FEAT_COMPAT_RO, + FEAT_INCOMPAT, + FEAT_MAX +}; + +char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags); +const char *btrfs_feature_set_name(enum btrfs_feature_set set); +int btrfs_sysfs_add_device(struct btrfs_device *device); +void btrfs_sysfs_remove_device(struct btrfs_device *device); +int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs); +void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs); +void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices); +void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info); +void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action); + +int __init btrfs_init_sysfs(void); +void __cold btrfs_exit_sysfs(void); +int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info); +void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info); +void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache); +int btrfs_sysfs_add_space_info_type(struct btrfs_space_info *space_info); +void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info); +void btrfs_sysfs_update_devid(struct btrfs_device *device); + +int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info, + struct btrfs_qgroup *qgroup); +void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info); +int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info); +void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info, + struct btrfs_qgroup *qgroup); +int btrfs_read_policy_to_enum(const char *str, s64 *value); + +#ifdef CONFIG_BTRFS_EXPERIMENTAL +int __init btrfs_read_policy_init(void); +char *btrfs_get_mod_read_policy(void); +#endif + +#endif -- cgit v1.3.1