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0143d148d1
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: |
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.. | ||
buffer.c | ||
config.c | ||
devices.c | ||
devio.c | ||
driver.c | ||
endpoint.c | ||
file.c | ||
generic.c | ||
hcd-pci.c | ||
hcd.c | ||
hub.c | ||
hub.h | ||
Kconfig | ||
ledtrig-usbport.c | ||
Makefile | ||
message.c | ||
notify.c | ||
of.c | ||
otg_productlist.h | ||
phy.c | ||
phy.h | ||
port.c | ||
quirks.c | ||
sysfs.c | ||
urb.c | ||
usb-acpi.c | ||
usb.c | ||
usb.h |