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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-05-14 13:27:11 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-05-14 18:39:57 +0200
commita0e710a7def471b8eb779ff551fc27701da49599 (patch)
tree0c789445eecbd28948dc854909bc381ec573cb85 /drivers
parent1449cb2c2253d37d998c3714aa9b95416d16d379 (diff)
downloadlinux-sh-a0e710a7def471b8eb779ff551fc27701da49599.tar.gz
USB: usbfs: fix mmap dma mismatch
In commit 2bef9aed6f0e ("usb: usbfs: correct kernel->user page attribute mismatch") we switched from always calling remap_pfn_range() to call dma_mmap_coherent() to handle issues with systems with non-coherent USB host controller drivers. Unfortunatly, as syzbot quickly told us, not all the world is host controllers with DMA support, so we need to check what host controller we are attempting to talk to before doing this type of allocation. Thanks to Christoph for the quick idea of how to fix this. Fixes: 2bef9aed6f0e ("usb: usbfs: correct kernel->user page attribute mismatch") Cc: Christoph Hellwig <hch@lst.de> Cc: Hillf Danton <hdanton@sina.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jeremy Linton <jeremy.linton@arm.com> Cc: stable <stable@vger.kernel.org> Reported-by: syzbot+353be47c9ce21b68b7ed@syzkaller.appspotmail.com Reviewed-by: Jeremy Linton <jeremy.linton@arm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20200514112711.1858252-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/usb/core/devio.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index b9db9812d6c5..d93d94d7ff50 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -251,9 +251,19 @@ static int usbdev_mmap(struct file *file, struct vm_area_struct *vma)
usbm->vma_use_count = 1;
INIT_LIST_HEAD(&usbm->memlist);
- if (dma_mmap_coherent(hcd->self.sysdev, vma, mem, dma_handle, size)) {
- dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
- return -EAGAIN;
+ if (hcd->localmem_pool || !hcd_uses_dma(hcd)) {
+ if (remap_pfn_range(vma, vma->vm_start,
+ virt_to_phys(usbm->mem) >> PAGE_SHIFT,
+ size, vma->vm_page_prot) < 0) {
+ dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
+ return -EAGAIN;
+ }
+ } else {
+ if (dma_mmap_coherent(hcd->self.sysdev, vma, mem, dma_handle,
+ size)) {
+ dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
+ return -EAGAIN;
+ }
}
vma->vm_flags |= VM_IO;