From c1755c25a7190494b45861284b4a30bd9cd813ff Mon Sep 17 00:00:00 2001 From: Breno Leitao Date: Wed, 18 Jan 2023 07:56:30 -0800 Subject: io_uring: Enable KASAN for request cache Every io_uring request is represented by struct io_kiocb, which is cached locally by io_uring (not SLAB/SLUB) in the list called submit_state.freelist. This patch simply enabled KASAN for this free list. This list is initially created by KMEM_CACHE, but later, managed by io_uring. This patch basically poisons the objects that are not used (i.e., they are the free list), and unpoisons it when the object is allocated/removed from the list. Touching these poisoned objects while in the freelist will cause a KASAN warning. Suggested-by: Jens Axboe Signed-off-by: Breno Leitao Reviewed-by: Pavel Begunkov Signed-off-by: Jens Axboe --- io_uring/io_uring.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'io_uring/io_uring.c') diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index c84dce6944db..407834255a59 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -151,7 +151,7 @@ static void io_move_task_work_from_local(struct io_ring_ctx *ctx); static void __io_submit_flush_completions(struct io_ring_ctx *ctx); static __cold void io_fallback_tw(struct io_uring_task *tctx); -static struct kmem_cache *req_cachep; +struct kmem_cache *req_cachep; struct sock *io_uring_get_socket(struct file *file) { @@ -230,6 +230,7 @@ static inline void req_fail_link_node(struct io_kiocb *req, int res) static inline void io_req_add_to_cache(struct io_kiocb *req, struct io_ring_ctx *ctx) { wq_stack_add_head(&req->comp_list, &ctx->submit_state.free_list); + kasan_poison_object_data(req_cachep, req); } static __cold void io_ring_ctx_ref_free(struct percpu_ref *ref) -- cgit v1.2.3