diff options
| author | Reinette Chatre <reinette.chatre@intel.com> | 2022-12-08 01:52:21 +0300 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2022-12-28 13:54:49 +0300 |
| commit | 1beeec45f9ac31eba52478379f70a5fa9c2ad005 (patch) | |
| tree | 4af7a99ced6fbde86c29838f3e30ae0df9e0c87f /drivers/dma/idxd | |
| parent | b51b75f0604f17c0f6f3b6f68f1a521a5cc6b04f (diff) | |
| download | linux-1beeec45f9ac31eba52478379f70a5fa9c2ad005.tar.xz | |
dmaengine: idxd: Prevent use after free on completion memory
On driver unload any pending descriptors are flushed at the
time the interrupt is freed:
idxd_dmaengine_drv_remove() ->
drv_disable_wq() ->
idxd_wq_free_irq() ->
idxd_flush_pending_descs().
If there are any descriptors present that need to be flushed this
flow triggers a "not present" page fault as below:
BUG: unable to handle page fault for address: ff391c97c70c9040
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
The address that triggers the fault is the address of the
descriptor that was freed moments earlier via:
drv_disable_wq()->idxd_wq_free_resources()
Fix the use after free by freeing the descriptors after any possible
usage. This is done after idxd_wq_reset() to ensure that the memory
remains accessible during possible completion writes by the device.
Fixes: 63c14ae6c161 ("dmaengine: idxd: refactor wq driver enable/disable operations")
Suggested-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/6c4657d9cff0a0a00501a7b928297ac966e9ec9d.1670452419.git.reinette.chatre@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma/idxd')
| -rw-r--r-- | drivers/dma/idxd/device.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c index c5523ced2e3a..cd792f3f9873 100644 --- a/drivers/dma/idxd/device.c +++ b/drivers/dma/idxd/device.c @@ -1407,11 +1407,11 @@ void drv_disable_wq(struct idxd_wq *wq) dev_warn(dev, "Clients has claim on wq %d: %d\n", wq->id, idxd_wq_refcount(wq)); - idxd_wq_free_resources(wq); idxd_wq_unmap_portal(wq); idxd_wq_drain(wq); idxd_wq_free_irq(wq); idxd_wq_reset(wq); + idxd_wq_free_resources(wq); percpu_ref_exit(&wq->wq_active); wq->type = IDXD_WQT_NONE; wq->client_count = 0; |