diff options
| author | Ruihan Li <lrh2000@pku.edu.cn> | 2023-05-15 16:09:55 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-29 18:14:28 +0300 |
| commit | 0143d148d1e882fb1538dc9974c94d63961719b9 (patch) | |
| tree | 81ec7174c2d10fd89b1f4176eceaa0757aa8a3d3 /drivers/usb/core/devio.c | |
| parent | 7b32040f6d7f885ffc09a6df7c17992d56d2eab8 (diff) | |
| download | linux-0143d148d1e882fb1538dc9974c94d63961719b9.tar.xz | |
usb: usbfs: Enforce page requirements for mmap
The current implementation of usbdev_mmap uses usb_alloc_coherent to
allocate memory pages that will later be mapped into the user space.
Meanwhile, usb_alloc_coherent employs three different methods to
allocate memory, as outlined below:
* If hcd->localmem_pool is non-null, it uses gen_pool_dma_alloc to
allocate memory;
* If DMA is not available, it uses kmalloc to allocate memory;
* Otherwise, it uses dma_alloc_coherent.
However, it should be noted that gen_pool_dma_alloc does not guarantee
that the resulting memory will be page-aligned. Furthermore, trying to
map slab pages (i.e., memory allocated by kmalloc) into the user space
is not resonable and can lead to problems, such as a type confusion bug
when PAGE_TABLE_CHECK=y [1].
To address these issues, this patch introduces hcd_alloc_coherent_pages,
which addresses the above two problems. Specifically,
hcd_alloc_coherent_pages uses gen_pool_dma_alloc_align instead of
gen_pool_dma_alloc to ensure that the memory is page-aligned. To replace
kmalloc, hcd_alloc_coherent_pages directly allocates pages by calling
__get_free_pages.
Reported-by: syzbot+fcf1a817ceb50935ce99@syzkaller.appspotmail.comm
Closes: https://lore.kernel.org/lkml/000000000000258e5e05fae79fc1@google.com/ [1]
Fixes: f7d34b445abc ("USB: Add support for usbfs zerocopy.")
Fixes: ff2437befd8f ("usb: host: Fix excessive alignment restriction for local memory allocations")
Cc: stable@vger.kernel.org
Signed-off-by: Ruihan Li <lrh2000@pku.edu.cn>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20230515130958.32471-2-lrh2000@pku.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core/devio.c')
| -rw-r--r-- | drivers/usb/core/devio.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index e501a03d6c70..3936ca7f7d2f 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -186,6 +186,7 @@ static int connected(struct usb_dev_state *ps) static void dec_usb_memory_use_count(struct usb_memory *usbm, int *count) { struct usb_dev_state *ps = usbm->ps; + struct usb_hcd *hcd = bus_to_hcd(ps->dev->bus); unsigned long flags; spin_lock_irqsave(&ps->lock, flags); @@ -194,8 +195,8 @@ static void dec_usb_memory_use_count(struct usb_memory *usbm, int *count) list_del(&usbm->memlist); spin_unlock_irqrestore(&ps->lock, flags); - usb_free_coherent(ps->dev, usbm->size, usbm->mem, - usbm->dma_handle); + hcd_buffer_free_pages(hcd, usbm->size, + usbm->mem, usbm->dma_handle); usbfs_decrease_memory_usage( usbm->size + sizeof(struct usb_memory)); kfree(usbm); @@ -247,8 +248,8 @@ static int usbdev_mmap(struct file *file, struct vm_area_struct *vma) goto error_decrease_mem; } - mem = usb_alloc_coherent(ps->dev, size, GFP_USER | __GFP_NOWARN, - &dma_handle); + mem = hcd_buffer_alloc_pages(hcd, + size, GFP_USER | __GFP_NOWARN, &dma_handle); if (!mem) { ret = -ENOMEM; goto error_free_usbm; |