77d5ad4048
skb free-ed in:
1/ condition 1: tipc_sk_filter_rcv -> tipc_sk_proto_rcv
2/ condition 2: tipc_sk_filter_rcv -> tipc_group_filter_msg
This leads to a "use-after-free" access in the next condition.
We fix this by intializing the variable at declaration, then it is safe
to check this variable to continue processing if condition matches.
syzbot report:
==================================================================
BUG: KASAN: use-after-free in tipc_sk_filter_rcv+0x2166/0x34f0
net/tipc/socket.c:2167
Read of size 4 at addr ffff88808ea58534 by task kworker/u4:0/7
CPU: 0 PID: 7 Comm: kworker/u4:0 Not tainted 5.0.0+ #61
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 01/01/2011
Workqueue: tipc_send tipc_conn_send_work
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x172/0x1f0 lib/dump_stack.c:113
print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
__asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131
tipc_sk_filter_rcv+0x2166/0x34f0 net/tipc/socket.c:2167
tipc_sk_enqueue net/tipc/socket.c:2254 [inline]
tipc_sk_rcv+0xc45/0x25a0 net/tipc/socket.c:2305
tipc_topsrv_kern_evt+0x3b7/0x580 net/tipc/topsrv.c:610
tipc_conn_send_to_sock+0x43e/0x5f0 net/tipc/topsrv.c:283
tipc_conn_send_work+0x65/0x80 net/tipc/topsrv.c:303
process_one_work+0x98e/0x1790 kernel/workqueue.c:2269
worker_thread+0x98/0xe40 kernel/workqueue.c:2415
kthread+0x357/0x430 kernel/kthread.c:253
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Reported-by: syzbot+e863893591cc7a622e40@syzkaller.appspotmail.com
Fixes:
|
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| 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 | ||
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.