[PATCH v2 1/7] xhci: mem: Carefully calculate size for memory allocations

From: Andy Shevchenko
Date: Wed Feb 08 2023 - 10:16:05 EST


Carefully calculate size for memory allocations, i.e. with help
of size_mul() macro from overflow.h.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci-mem.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index d0a9467aa5fc..c385513ad00b 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -9,6 +9,7 @@
*/

#include <linux/usb.h>
+#include <linux/overflow.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/dmapool.h>
@@ -568,7 +569,7 @@ static struct xhci_stream_ctx *xhci_alloc_stream_ctx(struct xhci_hcd *xhci,
gfp_t mem_flags)
{
struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
- size_t size = sizeof(struct xhci_stream_ctx) * num_stream_ctxs;
+ size_t size = size_mul(sizeof(struct xhci_stream_ctx), num_stream_ctxs);

if (size > MEDIUM_STREAM_ARRAY_SIZE)
return dma_alloc_coherent(dev, size,
@@ -1660,7 +1661,7 @@ static int scratchpad_alloc(struct xhci_hcd *xhci, gfp_t flags)
goto fail_sp;

xhci->scratchpad->sp_array = dma_alloc_coherent(dev,
- num_sp * sizeof(u64),
+ size_mul(sizeof(u64), num_sp),
&xhci->scratchpad->sp_dma, flags);
if (!xhci->scratchpad->sp_array)
goto fail_sp2;
@@ -1799,7 +1800,7 @@ int xhci_alloc_erst(struct xhci_hcd *xhci,
struct xhci_segment *seg;
struct xhci_erst_entry *entry;

- size = sizeof(struct xhci_erst_entry) * evt_ring->num_segs;
+ size = size_mul(sizeof(struct xhci_erst_entry), evt_ring->num_segs);
erst->entries = dma_alloc_coherent(xhci_to_hcd(xhci)->self.sysdev,
size, &erst->erst_dma_addr, flags);
if (!erst->entries)
@@ -1830,7 +1831,7 @@ xhci_free_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir)
if (!ir)
return;

- erst_size = sizeof(struct xhci_erst_entry) * (ir->erst.num_entries);
+ erst_size = sizeof(struct xhci_erst_entry) * ir->erst.num_entries;
if (ir->erst.entries)
dma_free_coherent(dev, erst_size,
ir->erst.entries,
--
2.39.1