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/fuse/dev.h | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 fs/fuse/dev.h (limited to 'fs/fuse/dev.h') diff --git a/fs/fuse/dev.h b/fs/fuse/dev.h new file mode 100644 index 000000000..aed69fd14 --- /dev/null +++ b/fs/fuse/dev.h @@ -0,0 +1,110 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _FS_FUSE_DEV_H +#define _FS_FUSE_DEV_H + +#include + +/** Maximum number of outstanding background requests */ +#define FUSE_DEFAULT_MAX_BACKGROUND 12 + +struct fuse_conn; +struct fuse_chan; +struct fuse_dev; +struct fuse_args; +struct fuse_copy_state; +struct fuse_backing_map; +struct file; +struct folio; +enum fuse_notify_code; + +struct fuse_chan_param { + unsigned int minor; + unsigned int max_write; + unsigned int max_pages; +}; + +struct fuse_chan *fuse_chan_new(void); +struct fuse_chan *fuse_dev_chan_new(void); +void fuse_chan_release(struct fuse_chan *fch); +void fuse_chan_free(struct fuse_chan *fch); +unsigned int fuse_chan_num_background(struct fuse_chan *fch); +unsigned int fuse_chan_max_background(struct fuse_chan *fch); +void fuse_chan_max_background_set(struct fuse_chan *fch, unsigned int val); +unsigned int fuse_chan_num_waiting(struct fuse_chan *fch); +void fuse_chan_set_fc(struct fuse_chan *fch, struct fuse_conn *fc); +void fuse_chan_set_initialized(struct fuse_chan *fch, struct fuse_chan_param *param); +void fuse_chan_io_uring_enable(struct fuse_chan *fch); +ssize_t fuse_chan_send(struct fuse_chan *fch, struct fuse_args *args); +int fuse_chan_send_bg(struct fuse_chan *fch, struct fuse_args *args, gfp_t gfp_flags); +int fuse_chan_send_notify_reply(struct fuse_chan *fch, struct fuse_args *args, u64 unique); +void fuse_chan_resend(struct fuse_chan *fch); + +struct fuse_forget_link *fuse_alloc_forget(void); +void fuse_chan_queue_forget(struct fuse_chan *fch, struct fuse_forget_link *forget, + u64 nodeid, u64 nlookup); + +DEFINE_FREE(fuse_chan_free, struct fuse_chan *, if (_T) fuse_chan_free(_T)) + +/** + * Initialize the client device + */ +int fuse_dev_init(void); + +/** + * Cleanup the client device + */ +void fuse_dev_cleanup(void); + +void fuse_dev_install(struct fuse_dev *fud, struct fuse_chan *fch); +bool fuse_dev_verify(struct fuse_dev *fud, struct fuse_chan *fch); +void fuse_dev_put(struct fuse_dev *fud); +bool fuse_dev_is_installed(struct fuse_dev *fud); +bool fuse_dev_is_sync_init(struct fuse_dev *fud); +struct fuse_dev *fuse_dev_grab(struct file *file); + +void fuse_init_server_timeout(struct fuse_chan *fch, unsigned int timeout); + +/* Abort all requests */ +void fuse_chan_abort(struct fuse_chan *fch, bool abort_with_err); +void fuse_chan_wait_aborted(struct fuse_chan *fch); + +/** + * Acquire reference to fuse_conn + */ +struct fuse_conn *fuse_conn_get(struct fuse_conn *fc); + +/** + * Release reference to fuse_conn + */ +void fuse_conn_put(struct fuse_conn *fc); + +dev_t fuse_conn_get_id(struct fuse_conn *fc); + +void fuse_end_polls(struct fuse_conn *fc); +int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code, + unsigned int size, struct fuse_copy_state *cs); + +int fuse_backing_open(struct fuse_conn *fc, struct fuse_backing_map *map); +int fuse_backing_close(struct fuse_conn *fc, int backing_id); + +int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size); +int fuse_copy_folio(struct fuse_copy_state *cs, struct folio **foliop, + unsigned offset, unsigned count, int zeroing); +void fuse_copy_finish(struct fuse_copy_state *cs); + +#ifdef CONFIG_FUSE_IO_URING +bool fuse_uring_enabled(void); +void fuse_uring_destruct(struct fuse_chan *fch); +#else /* CONFIG_FUSE_IO_URING */ +static inline bool fuse_uring_enabled(void) +{ + return false; +} + +static inline void fuse_uring_destruct(struct fuse_chan *fch) +{ +} +#endif /* CONFIG_FUSE_IO_URING */ + +#endif /* _FS_FUSE_DEV_H */ -- cgit v1.3.1