This is a note to let you know that I've just added the patch titled
io_uring: fix false positive KASAN warnings
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
io_uring-fix-false-positive-kasan-warnings.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 569f5308e54352a12181cc0185f848024c5443e8 Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@xxxxxxxxx>
Date: Wed, 9 Aug 2023 13:22:16 +0100
Subject: io_uring: fix false positive KASAN warnings
From: Pavel Begunkov <asml.silence@xxxxxxxxx>
commit 569f5308e54352a12181cc0185f848024c5443e8 upstream.
io_req_local_work_add() peeks into the work list, which can be executed
in the meanwhile. It's completely fine without KASAN as we're in an RCU
read section and it's SLAB_TYPESAFE_BY_RCU. With KASAN though it may
trigger a false positive warning because internal io_uring caches are
sanitised.
Remove sanitisation from the io_uring request cache for now.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 8751d15426a31 ("io_uring: reduce scheduling due to tw")
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Link: https://lore.kernel.org/r/c6fbf7a82a341e66a0007c76eefd9d57f2d3ba51.1691541473.git.asml.silence@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
io_uring/io_uring.c | 1 -
io_uring/io_uring.h | 1 -
2 files changed, 2 deletions(-)
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -231,7 +231,6 @@ static inline void req_fail_link_node(st
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)
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -361,7 +361,6 @@ static inline struct io_kiocb *io_extrac
struct io_kiocb *req;
req = container_of(ctx->submit_state.free_list.next, struct io_kiocb, comp_list);
- kasan_unpoison_object_data(req_cachep, req);
wq_stack_extract(&ctx->submit_state.free_list);
return req;
}
Patches currently in stable-queue which might be from asml.silence@xxxxxxxxx are
queue-6.4/io_uring-fix-drain-stalls-by-invalid-sqe.patch
queue-6.4/io_uring-break-out-of-iowq-iopoll-on-teardown.patch
queue-6.4/io_uring-fix-false-positive-kasan-warnings.patch
queue-6.4/io_uring-break-iopolling-on-signal.patch
