On Sun, Mar 01, 2020 at 11:20:43AM +0800, Macpaul Lin wrote:
On Fri, 2020-02-28 at 16:48 +0000, Catalin Marinas wrote:
On Wed, Feb 26, 2020 at 08:01:52PM +0800, Macpaul Lin wrote:
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index ce1d023..192935f 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -715,7 +715,20 @@ static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req) static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter) {
- ssize_t ret = copy_to_iter(data, data_len, iter);
- ssize_t ret;
+#if defined(CONFIG_ARM64)
- /*
* Replace tagged address passed by user space application before* copying.*/- if (IS_ENABLED(CONFIG_ARM64_TAGGED_ADDR_ABI) &&
(iter->type == ITER_IOVEC)) {*(unsigned long *)&iter->iov->iov_base =(unsigned long)untagged_addr(iter->iov->iov_base);- }
+#endif
- ret = copy_to_iter(data, data_len, iter); if (likely(ret == data_len)) return ret;
I had forgotten that we discussed a similar case already a few months ago (thanks to Evgenii for pointing out). Do you have this commit applied to your tree: df325e05a682 ("arm64: Validate tagged addresses in access_ok() called from kernel threads")?
Yes! We have that patch. I've also got Google's reply about referencing this patch in android kernel tree. https://android-review.googlesource.com/c/kernel/common/+/1186615
However, during my debugging process, I've dumped specific length (e.g., 24 bytes for the first request) AIO request buffer address both in adbd and in __range_ok(). Then I've found __range_ok() still always return false on address begin with "0x3c". Since untagged_addr() already called in __range_ok(), to set "TIF_TAGGED_ADDR" with adbd's user space buffer should be the possible solution. Hence I've send the v3 patch.
ffs_copy_to_iter() is called from a workqueue (ffs_user_copy_worker()). That's still in a kernel thread context but it doesn't have PF_KTHREAD set, hence __range_ok() rejects the tagged address. Can you try the diff below:
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 32fc8061aa76..2803143cad1f 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -68,7 +68,8 @@ static inline unsigned long __range_ok(const void __user *addr, unsigned long si * the user address before checking. */ if (IS_ENABLED(CONFIG_ARM64_TAGGED_ADDR_ABI) && - (current->flags & PF_KTHREAD || test_thread_flag(TIF_TAGGED_ADDR))) + (current->flags & (PF_KTHREAD | PF_WQ_WORKER) || + test_thread_flag(TIF_TAGGED_ADDR))) addr = untagged_addr(addr);
__chk_user_ptr(addr); -