0d773aaf5a
commit 80912cef18f16f8fe59d1fb9548d4364342be360 upstream. io_rsrc_ref_quiesce will unlock the uring while it waits for references to the io_rsrc_data to be killed. There are other places to the data that might add references to data via calls to io_rsrc_node_switch. There is a race condition where this reference can be added after the completion has been signalled. At this point the io_rsrc_ref_quiesce call will wake up and relock the uring, assuming the data is unused and can be freed - although it is actually being used. To fix this check in io_rsrc_ref_quiesce if a resource has been revived. Reported-by: syzbot+ca8bf833622a1662745b@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220222161751.995746-1-dylany@fb.com 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.