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. Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> --- v2: -- move kmsan_handle_urb() implementation to this patch Link: https://linux-review.googlesource.com/id/Ifa67fb72015d4de14c30e971556f99fc8b2ee506 --- drivers/usb/core/urb.c | 2 ++ include/linux/kmsan.h | 15 +++++++++++++++ mm/kmsan/hooks.c | 17 +++++++++++++++++ 3 files changed, 34 insertions(+) diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index 33d62d7e3929f..1fe3f23205624 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -8,6 +8,7 @@ #include <linux/bitops.h> #include <linux/slab.h> #include <linux/log2.h> +#include <linux/kmsan-checks.h> #include <linux/usb.h> #include <linux/wait.h> #include <linux/usb/hcd.h> @@ -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 55fe673ee1e84..e8b5c306c4aa1 100644 --- a/include/linux/kmsan.h +++ b/include/linux/kmsan.h @@ -19,6 +19,7 @@ struct page; struct kmem_cache; struct task_struct; struct scatterlist; +struct urb; #ifdef CONFIG_KMSAN @@ -235,6 +236,16 @@ 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) @@ -327,6 +338,10 @@ 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 8a6947a2a2f22..9aecbf2825837 100644 --- a/mm/kmsan/hooks.c +++ b/mm/kmsan/hooks.c @@ -17,6 +17,7 @@ #include <linux/scatterlist.h> #include <linux/slab.h> #include <linux/uaccess.h> +#include <linux/usb.h> #include "../internal.h" #include "../slab.h" @@ -252,6 +253,22 @@ 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); +} +EXPORT_SYMBOL(kmsan_handle_urb); + static void kmsan_handle_dma_page(const void *addr, size_t size, enum dma_data_direction dir) { -- 2.37.0.rc0.161.g10f37bed90-goog
