Messages in this thread | | | Date | Tue, 17 May 2022 10:36:57 +0200 | From | Christoph Hellwig <> | Subject | Re: [PATCH] iommu/dma: Fix check for error return from iommu_map_sg_atomic() |
| |
On Fri, May 13, 2022 at 05:39:48PM +0200, Niklas Schnelle wrote: > In __iommu_dma_alloc_noncontiguous() the value returned by > iommu_map_sg_atomic() is checked for being smaller than size. Before > commit ad8f36e4b6b1 ("iommu: return full error code from > iommu_map_sg[_atomic]()") this simply checked if the requested size was > successfully mapped. > > After that commit iommu_map_sg_atomic() may also return a negative > error value. In principle this too would be covered by the existing > check. There is one problem however, as size is of type size_t while the > return type of iommu_map_sg_atomic() is now of type ssize_t the latter gets > converted to size_t and negative error values end up as very large > positive values making the check succeed. Fix this by making the return > type visible with a local variable and add an explicit cast to ssize_t. > > Fixes: ad8f36e4b6b1 ("iommu: return full error code from iommu_map_sg[_atomic]()") > Cc: stable@vger.kernel.org > Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
I don't see what the point of the newly added local variable is here. Just casting size should be all that is needed as far as I can tell.
| |