Linux kernel modifications for the Kernel Hacking exam
f6db909641
b->media->send_msg() requires rcu_read_lock(), as we can see
elsewhere in tipc, tipc_bearer_xmit, tipc_bearer_xmit_skb
and tipc_bearer_bc_xmit().
Syzbot has reported this issue as:
net/tipc/bearer.c:466 suspicious rcu_dereference_check() usage!
Workqueue: cryptd cryptd_queue_worker
Call Trace:
tipc_l2_send_msg+0x354/0x420 net/tipc/bearer.c:466
tipc_aead_encrypt_done+0x204/0x3a0 net/tipc/crypto.c:761
cryptd_aead_crypt+0xe8/0x1d0 crypto/cryptd.c:739
cryptd_queue_worker+0x118/0x1b0 crypto/cryptd.c:181
process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x3b5/0x4a0 kernel/kthread.c:291
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
So fix it by calling rcu_read_lock() in tipc_aead_encrypt_done()
for b->media->send_msg().
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| 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 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.