ax25: NPD bug when detaching AX25 device
stable inclusion from linux-4.19.235 commit bd05a8f1b7368ef4f7845548312fc61ab4fa63ce category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I53VJO CVE: CVE-2022-1199 -------------------------------- commit 1ade48d0c27d5da1ccf4b583d8c5fc8b534a3ac8 upstream. The existing cleanup routine implementation is not well synchronized with the syscall routine. When a device is detaching, below race could occur. static int ax25_sendmsg(...) { ... lock_sock() ax25 = sk_to_ax25(sk); if (ax25->ax25_dev == NULL) // CHECK ... ax25_queue_xmit(skb, ax25->ax25_dev->dev); // USE ... } static void ax25_kill_by_device(...) { ... if (s->ax25_dev == ax25_dev) { s->ax25_dev = NULL; ... } Other syscall functions like ax25_getsockopt, ax25_getname, ax25_info_show also suffer from similar races. To fix them, this patch introduce lock_sock() into ax25_kill_by_device in order to guarantee that the nullify action in cleanup routine cannot proceed when another socket request is pending. Signed-off-by:Hanjie Wu <nagi@zju.edu.cn> Signed-off-by:
Lin Ma <linma@zju.edu.cn> Signed-off-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
Zhengchao Shao <shaozhengchao@huawei.com> Reviewed-by:
Wei Yongjun <weiyongjun1@huawei.com> Reviewed-by:
Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by:
Yongqiang Liu <liuyongqiang13@huawei.com>
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