mirror of
https://github.com/torvalds/linux.git
synced 2026-08-01 03:59:40 +02:00
Linux kernel source tree
1649714b93
There is one use-after-free warning when running NBD_CMD_CONNECT and
NBD_CLEAR_SOCK:
nbd_genl_connect
nbd_alloc_and_init_config // config_refs=1
nbd_start_device // config_refs=2
set NBD_RT_HAS_CONFIG_REF open nbd // config_refs=3
recv_work done // config_refs=2
NBD_CLEAR_SOCK // config_refs=1
close nbd // config_refs=0
refcount_inc -> uaf
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 24 PID: 1014 at lib/refcount.c:25 refcount_warn_saturate+0x12e/0x290
nbd_genl_connect+0x16d0/0x1ab0
genl_family_rcv_msg_doit+0x1f3/0x310
genl_rcv_msg+0x44a/0x790
The issue can be easily reproduced by adding a small delay before
refcount_inc(&nbd->config_refs) in nbd_genl_connect():
mutex_unlock(&nbd->config_lock);
if (!ret) {
set_bit(NBD_RT_HAS_CONFIG_REF, &config->runtime_flags);
+ printk("before sleep\n");
+ mdelay(5 * 1000);
+ printk("after sleep\n");
refcount_inc(&nbd->config_refs);
nbd_connect_reply(info, nbd->index);
}
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .pylintrc | ||
| .rustfmt.toml | ||
| 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 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.