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 --- drivers/md/bcache/request.h | 47 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 drivers/md/bcache/request.h (limited to 'drivers/md/bcache/request.h') diff --git a/drivers/md/bcache/request.h b/drivers/md/bcache/request.h new file mode 100644 index 000000000..46bbef00a --- /dev/null +++ b/drivers/md/bcache/request.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _BCACHE_REQUEST_H_ +#define _BCACHE_REQUEST_H_ + +struct data_insert_op { + struct closure cl; + struct cache_set *c; + struct bio *bio; + struct workqueue_struct *wq; + + unsigned int inode; + uint16_t write_point; + uint16_t write_prio; + blk_status_t status; + + union { + uint16_t flags; + + struct { + unsigned int bypass:1; + unsigned int writeback:1; + unsigned int flush_journal:1; + unsigned int csum:1; + + unsigned int replace:1; + unsigned int replace_collision:1; + + unsigned int insert_data_done:1; + }; + }; + + struct keylist insert_keys; + BKEY_PADDED(replace_key); +}; + +unsigned int bch_get_congested(const struct cache_set *c); +CLOSURE_CALLBACK(bch_data_insert); + +void bch_cached_dev_request_init(struct cached_dev *dc); +void cached_dev_submit_bio(struct bio *bio); + +void bch_flash_dev_request_init(struct bcache_device *d); +void flash_dev_submit_bio(struct bio *bio); + +extern struct kmem_cache *bch_search_cache; + +#endif /* _BCACHE_REQUEST_H_ */ -- cgit v1.3.1