e944f1e37b
commit 0d7c1153d9291197c1dc473cfaade77acb874b4b upstream. In io_recv(), if import_single_range() fails, the @flags variable is uninitialized, then it will goto out_free. After the goto, the compiler doesn't know that (ret < min_ret) is always true, so it thinks the "if ((flags & MSG_WAITALL) ..." path could be taken. The complaint comes from gcc-9 (Debian 9.3.0-22) 9.3.0: ``` fs/io_uring.c:5238 io_recvfrom() error: uninitialized symbol 'flags' ``` Fix this by bypassing the @ret and @flags check when import_single_range() fails. Reasons: 1. import_single_range() only returns -EFAULT when it fails. 2. At that point, @flags is uninitialized and shouldn't be read. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reported-by: "Chen, Rong A" <rong.a.chen@intel.com> Link: https://lore.gnuweeb.org/timl/d33bb5a9-8173-f65b-f653-51fc0681c6d6@intel.com/ Cc: Pavel Begunkov <asml.silence@gmail.com> Suggested-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Fixes: 7297ce3d59449de49d3c9e1f64ae25488750a1fc ("io_uring: improve send/recv error handling") Signed-off-by: Alviro Iskandar Setiawan <alviro.iskandar@gmail.com> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Link: https://lore.kernel.org/r/20220207140533.565411-1-ammarfaizi2@gnuweeb.org 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.