Jens Axboe 94ad56f61b io_uring/tctx: work around xa_store() allocation error issue
[ Upstream commit 7eb75ce7527129d7f1fee6951566af409a37a1c4 ]

syzbot triggered the following WARN_ON:

WARNING: CPU: 0 PID: 16 at io_uring/tctx.c:51 __io_uring_free+0xfa/0x140 io_uring/tctx.c:51

which is the

WARN_ON_ONCE(!xa_empty(&tctx->xa));

sanity check in __io_uring_free() when a io_uring_task is going through
its final put. The syzbot test case includes injecting memory allocation
failures, and it very much looks like xa_store() can fail one of its
memory allocations and end up with ->head being non-NULL even though no
entries exist in the xarray.

Until this issue gets sorted out, work around it by attempting to
iterate entries in our xarray, and WARN_ON_ONCE() if one is found.

Reported-by: syzbot+cc36d44ec9f368e443d3@syzkaller.appspotmail.com
Link: https://lore.kernel.org/io-uring/673c1643.050a0220.87769.0066.GAE@google.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14 19:54:49 +01:00
2024-12-14 19:53:51 +01:00
2024-12-14 19:54:40 +01:00
2022-09-28 09:02:20 +02:00
2024-11-22 15:37:35 +01:00

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.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%