[PATCH] rspiusb: Check usb_buffer_map_sg() retval
Roel Kluin
roel.kluin at gmail.com
Sat Aug 22 16:56:27 UTC 2009
usb_buffer_map_sg() may return -1, check this directly.
Signed-off-by: Roel Kluin <roel.kluin at gmail.com>
---
>> usb_buffer_map_sg() may return -1. This will result in a read from
>> pdx->PixelUrb[frameInfo][-1]
>> + if (i == 0)
>> + return -EINVAL;
> This is rather pointless. If usb_buffer_map_sg returns error (negative
> value), we will die earlier on most machines, since we pass some
> 0xffffffXX to kmalloc as a size.
>
> The proper fix is to check usb_buffer_map_sg retval here.
good point,
How about this?
sgEntries[frameInfo] is unsigned so we cannot test `< 0' on that.
diff --git a/drivers/staging/rspiusb/rspiusb.c b/drivers/staging/rspiusb/rspiusb.c
index 04e2f92..acafbd8 100644
--- a/drivers/staging/rspiusb/rspiusb.c
+++ b/drivers/staging/rspiusb/rspiusb.c
@@ -611,6 +611,7 @@ static int MapUserBuffer(struct ioctl_struct *io, struct device_extension *pdx)
int i = 0;
int k = 0;
int err = 0;
+ int ret;
struct page **maplist_p;
int numPagesRequired;
@@ -687,9 +688,13 @@ static int MapUserBuffer(struct ioctl_struct *io, struct device_extension *pdx)
} else {
pdx->sgl[frameInfo][0].length = count;
}
- pdx->sgEntries[frameInfo] =
- usb_buffer_map_sg(pdx->udev, epAddr, pdx->sgl[frameInfo],
- pdx->maplist_numPagesMapped[frameInfo]);
+ ret = usb_buffer_map_sg(pdx->udev, epAddr, pdx->sgl[frameInfo],
+ pdx->maplist_numPagesMapped[frameInfo]);
+ if (ret < 0)
+ return -EINVAL;
+
+ pdx->sgEntries[frameInfo] = ret;
+
dbg("number of sgEntries = %d", pdx->sgEntries[frameInfo]);
pdx->userBufMapped = 1;
vfree(maplist_p);
@@ -716,8 +721,6 @@ static int MapUserBuffer(struct ioctl_struct *io, struct device_extension *pdx)
pdx->PixelUrb[frameInfo][i]->transfer_flags =
URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT;
}
- if (i == 0)
- return -EINVAL;
/* only interrupt when last URB completes */
pdx->PixelUrb[frameInfo][--i]->transfer_flags &= ~URB_NO_INTERRUPT;
pdx->pendedPixelUrbs[frameInfo] =
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