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/dma/idxd/defaults.c | 51 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 drivers/dma/idxd/defaults.c (limited to 'drivers/dma/idxd/defaults.c') diff --git a/drivers/dma/idxd/defaults.c b/drivers/dma/idxd/defaults.c new file mode 100644 index 000000000..2bbbcd02a --- /dev/null +++ b/drivers/dma/idxd/defaults.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2023 Intel Corporation. All rights rsvd. */ +#include +#include "idxd.h" + +int idxd_load_iaa_device_defaults(struct idxd_device *idxd) +{ + struct idxd_engine *engine; + struct idxd_group *group; + struct idxd_wq *wq; + + if (!test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags)) + return 0; + + wq = idxd->wqs[0]; + + if (wq->state != IDXD_WQ_DISABLED) + return -EPERM; + + /* set mode to "dedicated" */ + set_bit(WQ_FLAG_DEDICATED, &wq->flags); + wq->threshold = 0; + + /* only setting up 1 wq, so give it all the wq space */ + wq->size = idxd->max_wq_size; + + /* set priority to 10 */ + wq->priority = 10; + + /* set type to "kernel" */ + wq->type = IDXD_WQT_KERNEL; + + /* set wq group to 0 */ + group = idxd->groups[0]; + wq->group = group; + group->num_wqs++; + + /* set name to "iaa_crypto" */ + strscpy_pad(wq->name, "iaa_crypto"); + + /* set driver_name to "crypto" */ + strscpy_pad(wq->driver_name, "crypto"); + + engine = idxd->engines[0]; + + /* set engine group to 0 */ + engine->group = idxd->groups[0]; + engine->group->num_engines++; + + return 0; +} -- cgit v1.3.1