Catalin Marinas df325e05a6 arm64: Validate tagged addresses in access_ok() called from kernel threads ... __range_ok(), invoked from access_ok(), clears the tag of the user address only if CONFIG_ARM64_TAGGED_ADDR_ABI is enabled and the thread opted in to the relaxed ABI. The latter sets the TIF_TAGGED_ADDR thread flag. In the case of asynchronous I/O (e.g. io_submit()), the access_ok() may be called from a kernel thread. Since kernel threads don't have TIF_TAGGED_ADDR set, access_ok() will fail for valid tagged user addresses. Example from the ffs_user_copy_worker() thread: use_mm(io_data->mm); ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data); unuse_mm(io_data->mm); Relax the __range_ok() check to always untag the user address if called in the context of a kernel thread. The user pointers would have already been checked via aio_setup_rw() -> import_{single_range,iovec}() at the time of the asynchronous I/O request. Fixes: 63f0c60379 ("arm64: Introduce prctl() options to control the tagged user addresses ABI") Cc: <stable@vger.kernel.org> # 5.4.x- Cc: Will Deacon <will@kernel.org> Reported-by: Evgenii Stepanov <eugenis@google.com> Tested-by: Evgenii Stepanov <eugenis@google.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>		2019-12-06 12:02:56 +00:00
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asm	arm64: Validate tagged addresses in access_ok() called from kernel threads	2019-12-06 12:02:56 +00:00
uapi/asm	* s390: ioctl hardening, selftests	2019-09-18 09:49:13 -07:00