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 --- block/blk-pm.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 block/blk-pm.h (limited to 'block/blk-pm.h') diff --git a/block/blk-pm.h b/block/blk-pm.h new file mode 100644 index 000000000..8a5a0d4b3 --- /dev/null +++ b/block/blk-pm.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _BLOCK_BLK_PM_H_ +#define _BLOCK_BLK_PM_H_ + +#include + +#ifdef CONFIG_PM +static inline int blk_pm_resume_queue(const bool pm, struct request_queue *q) +{ + if (!q->dev || !blk_queue_pm_only(q)) + return 1; /* Nothing to do */ + if (pm && q->rpm_status != RPM_SUSPENDED) + return 1; /* Request allowed */ + pm_request_resume(q->dev); + return 0; +} + +static inline void blk_pm_mark_last_busy(struct request *rq) +{ + if (rq->q->dev && !(rq->rq_flags & RQF_PM)) + pm_runtime_mark_last_busy(rq->q->dev); +} +#else +static inline int blk_pm_resume_queue(const bool pm, struct request_queue *q) +{ + return 1; +} + +static inline void blk_pm_mark_last_busy(struct request *rq) +{ +} +#endif + +#endif /* _BLOCK_BLK_PM_H_ */ -- cgit v1.3.1