From 553a80188a5d7164d2b0688b06bf3fe297023bfe Mon Sep 17 00:00:00 2001 From: Alexander Potapenko Date: Thu, 15 Sep 2022 17:03:57 +0200 Subject: [PATCH] kmsan: handle memory sent to/from USB Depending on the value of is_out kmsan_handle_urb() KMSAN either marks the data copied to the kernel from a USB device as initialized, or checks the data sent to the device for being initialized. Link: https://lkml.kernel.org/r/20220915150417.722975-24-glider@google.com Signed-off-by: Alexander Potapenko Cc: Alexander Viro Cc: Alexei Starovoitov Cc: Andrey Konovalov Cc: Andrey Konovalov Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Christoph Hellwig Cc: Christoph Lameter Cc: David Rientjes Cc: Dmitry Vyukov Cc: Eric Biggers Cc: Eric Biggers Cc: Eric Dumazet Cc: Greg Kroah-Hartman Cc: Herbert Xu Cc: Ilya Leoshkevich Cc: Ingo Molnar Cc: Jens Axboe Cc: Joonsoo Kim Cc: Kees Cook Cc: Marco Elver Cc: Mark Rutland Cc: Matthew Wilcox Cc: Michael S. Tsirkin Cc: Pekka Enberg Cc: Peter Zijlstra Cc: Petr Mladek Cc: Stephen Rothwell Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vegard Nossum Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- drivers/usb/core/urb.c | 2 ++ include/linux/kmsan.h | 15 +++++++++++++++ mm/kmsan/hooks.c | 16 ++++++++++++++++ 3 files changed, 33 insertions(+) diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index 33d62d7e3929..9f3c54032556 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include @@ -426,6 +427,7 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL | URB_DMA_SG_COMBINED); urb->transfer_flags |= (is_out ? URB_DIR_OUT : URB_DIR_IN); + kmsan_handle_urb(urb, is_out); if (xfertype != USB_ENDPOINT_XFER_CONTROL && dev->state < USB_STATE_CONFIGURED) diff --git a/include/linux/kmsan.h b/include/linux/kmsan.h index dac296da45c5..c473e0e21683 100644 --- a/include/linux/kmsan.h +++ b/include/linux/kmsan.h @@ -18,6 +18,7 @@ struct page; struct kmem_cache; struct task_struct; struct scatterlist; +struct urb; #ifdef CONFIG_KMSAN @@ -203,6 +204,16 @@ void kmsan_handle_dma(struct page *page, size_t offset, size_t size, void kmsan_handle_dma_sg(struct scatterlist *sg, int nents, enum dma_data_direction dir); +/** + * kmsan_handle_urb() - Handle a USB data transfer. + * @urb: struct urb pointer. + * @is_out: data transfer direction (true means output to hardware). + * + * If @is_out is true, KMSAN checks the transfer buffer of @urb. Otherwise, + * KMSAN initializes the transfer buffer. + */ +void kmsan_handle_urb(const struct urb *urb, bool is_out); + #else static inline void kmsan_init_shadow(void) @@ -295,6 +306,10 @@ static inline void kmsan_handle_dma_sg(struct scatterlist *sg, int nents, { } +static inline void kmsan_handle_urb(const struct urb *urb, bool is_out) +{ +} + #endif #endif /* _LINUX_KMSAN_H */ diff --git a/mm/kmsan/hooks.c b/mm/kmsan/hooks.c index 563c09443a37..79d7e73e2cfd 100644 --- a/mm/kmsan/hooks.c +++ b/mm/kmsan/hooks.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "../internal.h" #include "../slab.h" @@ -245,6 +246,21 @@ void kmsan_copy_to_user(void __user *to, const void *from, size_t to_copy, } EXPORT_SYMBOL(kmsan_copy_to_user); +/* Helper function to check an URB. */ +void kmsan_handle_urb(const struct urb *urb, bool is_out) +{ + if (!urb) + return; + if (is_out) + kmsan_internal_check_memory(urb->transfer_buffer, + urb->transfer_buffer_length, + /*user_addr*/ 0, REASON_SUBMIT_URB); + else + kmsan_internal_unpoison_memory(urb->transfer_buffer, + urb->transfer_buffer_length, + /*checked*/ false); +} + static void kmsan_handle_dma_page(const void *addr, size_t size, enum dma_data_direction dir) {