In _scif_prog_signal(), a DMA pool is allocated if the MIC Coprocessor is
not X100, i.e., the boolean variable 'x100' is false. This DMA pool will be
freed eventually through the callback function scif_prog_signal_cb() with
the parameter of 'status', which actually points to the start of DMA pool.
Specifically, in scif_prog_signal_cb(), the 'ep' field and the
'src_dma_addr' field of 'status' are used to free the DMA pool by invoking
dma_pool_free(). Given that 'status' points to the start address of the DMA
pool, both 'status->ep' and 'status->src_dma_addr' are in the DMA pool. And
so, the device has the permission to access them. Even worse, a malicious
device can modify them. As a result, dma_pool_free() will not succeed.
To avoid the above issue, this patch introduces a new data structure, i.e.,
scif_cb_arg, to store the arguments required by the call back function. A
variable 'cb_arg' is allocated in _scif_prog_signal() to pass the
arguments. 'cb_arg' will be freed after dma_pool_free() in
scif_prog_signal_cb().
Signed-off-by: Wenwen Wang <wang6...@umn.edu>
---
drivers/misc/mic/scif/scif_fence.c | 22 +++++++++++++++++-----
drivers/misc/mic/scif/scif_rma.h | 13 +++++++++++++
2 files changed, 30 insertions(+), 5 deletions(-)
diff --git a/drivers/misc/mic/scif/scif_fence.c
b/drivers/misc/mic/scif/scif_fence.c
index 7bb929f..2e7ce6a 100644
--- a/drivers/misc/mic/scif/scif_fence.c
+++ b/drivers/misc/mic/scif/scif_fence.c
@@ -195,10 +195,11 @@ static inline void *scif_get_local_va(off_t off, struct
scif_window *window)
static void scif_prog_signal_cb(void *arg)
{
- struct scif_status *status = arg;
+ struct scif_cb_arg *cb_arg = arg;
- dma_pool_free(status->ep->remote_dev->signal_pool, status,
- status->src_dma_addr);
+ dma_pool_free(cb_arg->ep->remote_dev->signal_pool, cb_arg->status,
+ cb_arg->src_dma_addr);
+ kfree(cb_arg);
}
static int _scif_prog_signal(scif_epd_t epd, dma_addr_t dst, u64 val)
@@ -209,6 +210,7 @@ static int _scif_prog_signal(scif_epd_t epd, dma_addr_t
dst, u64 val)
bool x100 = !is_dma_copy_aligned(chan->device, 1, 1, 1);
struct dma_async_tx_descriptor *tx;
struct scif_status *status = NULL;
+ struct scif_cb_arg *cb_arg = NULL;
dma_addr_t src;
dma_cookie_t cookie;
int err;
@@ -257,8 +259,16 @@ static int _scif_prog_signal(scif_epd_t epd, dma_addr_t
dst, u64 val)
goto dma_fail;
}
if (!x100) {
+ cb_arg = kmalloc(sizeof(*cb_arg), GFP_KERNEL);
+ if (!cb_arg) {
+ err = -ENOMEM;
+ goto dma_fail;
+ }
+ cb_arg->src_dma_addr = src;
+ cb_arg->status = status;
+ cb_arg->ep = ep;
tx->callback = scif_prog_signal_cb;
- tx->callback_param = status;
+ tx->callback_param = cb_arg;
}
cookie = tx->tx_submit(tx);
if (dma_submit_error(cookie)) {
@@ -270,9 +280,11 @@ static int _scif_prog_signal(scif_epd_t epd, dma_addr_t
dst, u64 val)
dma_async_issue_pending(chan);
return 0;
dma_fail:
- if (!x100)
+ if (!x100) {
dma_pool_free(ep->remote_dev->signal_pool, status,
src - offsetof(struct scif_status, val));
+ kfree(cb_arg);
+ }
alloc_fail:
return err;
}
diff --git a/drivers/misc/mic/scif/scif_rma.h b/drivers/misc/mic/scif/scif_rma.h
index fa67222..84af303 100644
--- a/drivers/misc/mic/scif/scif_rma.h
+++ b/drivers/misc/mic/scif/scif_rma.h
@@ -206,6 +206,19 @@ struct scif_status {
};
/*
+ * struct scif_cb_arg - Stores the argument of the callback func
+ *
+ * @src_dma_addr: Source buffer DMA address
+ * @status: DMA status
+ * @ep: SCIF endpoint
+ */
+struct scif_cb_arg {
+ dma_addr_t src_dma_addr;
+ struct scif_status *status;
+ struct scif_endpt *ep;
+};
+
+/*
* struct scif_window - Registration Window for Self and Remote
*
* @nr_pages: Number of pages which is defined as a s64 instead of an int
--
2.7.4
