On Sat, 16 Oct 2021 at 13:26, Zheyu Ma <zheyuma97@xxxxxxxxx> wrote: > > In r592_remove(), the driver will free dma after freeing the host, which > may cause a UAF bug. > > The following log reveals it: > > [ 45.361796 ] BUG: KASAN: use-after-free in r592_remove+0x269/0x350 [r592] > [ 45.364286 ] Call Trace: > [ 45.364472 ] dump_stack_lvl+0xa8/0xd1 > [ 45.364751 ] print_address_description+0x87/0x3b0 > [ 45.365137 ] kasan_report+0x172/0x1c0 > [ 45.365415 ] ? r592_remove+0x269/0x350 [r592] > [ 45.365834 ] ? r592_remove+0x269/0x350 [r592] > [ 45.366168 ] __asan_report_load8_noabort+0x14/0x20 > [ 45.366531 ] r592_remove+0x269/0x350 [r592] > [ 45.378785 ] > [ 45.378903 ] Allocated by task 4674: > [ 45.379162 ] ____kasan_kmalloc+0xb5/0xe0 > [ 45.379455 ] __kasan_kmalloc+0x9/0x10 > [ 45.379730 ] __kmalloc+0x150/0x280 > [ 45.379984 ] memstick_alloc_host+0x2a/0x190 > [ 45.380664 ] > [ 45.380781 ] Freed by task 5509: > [ 45.381014 ] kasan_set_track+0x3d/0x70 > [ 45.381293 ] kasan_set_free_info+0x23/0x40 > [ 45.381635 ] ____kasan_slab_free+0x10b/0x140 > [ 45.381950 ] __kasan_slab_free+0x11/0x20 > [ 45.382241 ] slab_free_freelist_hook+0x81/0x150 > [ 45.382575 ] kfree+0x13e/0x290 > [ 45.382805 ] memstick_free+0x1c/0x20 > [ 45.383070 ] device_release+0x9c/0x1d0 > [ 45.383349 ] kobject_put+0x2ef/0x4c0 > [ 45.383616 ] put_device+0x1f/0x30 > [ 45.383865 ] memstick_free_host+0x24/0x30 > [ 45.384162 ] r592_remove+0x242/0x350 [r592] > [ 45.384473 ] pci_device_remove+0xa9/0x250 > > Signed-off-by: Zheyu Ma <zheyuma97@xxxxxxxxx> Applied for next, thanks! Kind regards Uffe > --- > drivers/memstick/host/r592.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/memstick/host/r592.c b/drivers/memstick/host/r592.c > index e79a0218c492..1d35d147552d 100644 > --- a/drivers/memstick/host/r592.c > +++ b/drivers/memstick/host/r592.c > @@ -838,15 +838,15 @@ static void r592_remove(struct pci_dev *pdev) > } > memstick_remove_host(dev->host); > > + if (dev->dummy_dma_page) > + dma_free_coherent(&pdev->dev, PAGE_SIZE, dev->dummy_dma_page, > + dev->dummy_dma_page_physical_address); > + > free_irq(dev->irq, dev); > iounmap(dev->mmio); > pci_release_regions(pdev); > pci_disable_device(pdev); > memstick_free_host(dev->host); > - > - if (dev->dummy_dma_page) > - dma_free_coherent(&pdev->dev, PAGE_SIZE, dev->dummy_dma_page, > - dev->dummy_dma_page_physical_address); > } > > #ifdef CONFIG_PM_SLEEP > -- > 2.17.6 >
