5afb4bf9fc
syzbot complains about an unmapping failure:
[ 108.070381][ T14] kernel BUG at mm/gup.c:71!
[ 108.070502][ T14] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
[ 108.123672][ T14] Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20250221-8.fc42 02/21/2025
[ 108.127458][ T14] Workqueue: iou_exit io_ring_exit_work
[ 108.174205][ T14] Call trace:
[ 108.175649][ T14] sanity_check_pinned_pages+0x7cc/0x7d0 (P)
[ 108.178138][ T14] unpin_user_page+0x80/0x10c
[ 108.180189][ T14] io_release_ubuf+0x84/0xf8
[ 108.182196][ T14] io_free_rsrc_node+0x250/0x57c
[ 108.184345][ T14] io_rsrc_data_free+0x148/0x298
[ 108.186493][ T14] io_sqe_buffers_unregister+0x84/0xa0
[ 108.188991][ T14] io_ring_ctx_free+0x48/0x480
[ 108.191057][ T14] io_ring_exit_work+0x764/0x7d8
[ 108.193207][ T14] process_one_work+0x7e8/0x155c
[ 108.195431][ T14] worker_thread+0x958/0xed8
[ 108.197561][ T14] kthread+0x5fc/0x75c
[ 108.199362][ T14] ret_from_fork+0x10/0x20
We can pin a tail page of a folio, but then io_uring will try to unpin
the head page of the folio. While it should be fine in terms of keeping
the page actually alive, mm folks say it's wrong and triggers a debug
warning. Use unpin_user_folio() instead of unpin_user_page*.
Cc: stable@vger.kernel.org
Debugged-by: David Hildenbrand <david@redhat.com>
Reported-by: syzbot+1d335893772467199ab6@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/683f1551.050a0220.55ceb.0017.GAE@google.com
Fixes:
|
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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 reStructuredText 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.