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> --- 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
