On 1/23/23 15:23, Greg KH wrote:
On Mon, Jan 23, 2023 at 03:03:24PM +0000, Pavel Begunkov wrote:
[ upstream commit 8579538c89e33ce78be2feb41e07489c8cbf8f31 ]
IORING_SETUP_R_DISABLED rings don't have the submitter task set, so
it's not always safe to use ->submitter_task. Disallow posting msg_ring
messaged to disabled rings. Also add task NULL check for loosy sync
around testing for IORING_SETUP_R_DISABLED.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 6d043ee1164ca ("io_uring: do msg_ring in target task via tw")
This commit is only in 6.2-rc1, so is it really relevant for this commit
to go to 6.1?
In short, yes.
The upstream commit fixes a bug in 6.2, that's the Fixes tag, but
it also adjusts behaviour of the feature, which came in earlier
kernels. My bad I didn't split the patch in two.
I also thought Jens added a second Fixes tag but it's not there.
Fixes: 4f57f06ce2186 ("io_uring: add support for IORING_OP_MSG_RING command")
--
Pavel Begunkov
