0ceb7a9230
commit 72bd80252feeb3bef8724230ee15d9f7ab541c6e upstream. If we use IORING_OP_RECV with provided buffers and pass in '0' as the length of the request, the length is retrieved from the selected buffer. If MSG_WAITALL is also set and we get a short receive, then we may hit the retry path which decrements sr->len and increments the buffer for a retry. However, the length is still zero at this point, which means that sr->len now becomes huge and import_ubuf() will cap it to MAX_RW_COUNT and subsequently return -EFAULT for the range as a whole. Fix this by always assigning sr->len once the buffer has been selected. Cc: stable@vger.kernel.org Fixes: 7ba89d2af17a ("io_uring: ensure recv and recvmsg handle MSG_WAITALL correctly") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.