MGASA-2017-0090

This kernel-linus update is based on upstream 4.4.55 and fixes at least the following security issues:

Race condition in drivers/tty/n_hdlc.c in the Linux kernel through 4.10.1 allows local users to gain privileges or cause a denial of service (double free) by setting the HDLC line discipline (CVE-2017-2636).

Race condition in net/packet/afpacket.c in the Linux kernel before 4.9.13 allows local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via a multithreaded application that makes PACKETFANOUT setsockopt system calls (CVE-2017-6346).

The ipcmsgrecvchecksum function in net/ipv4/ipsockglue.c in the Linux kernel before 4.10.1 has incorrect expectations about skb data layout, which allows local users to cause a denial of service (buffer over-read) or possibly have unspecified other impact via crafted system calls, as demonstrated by use of the MSG_MORE flag in conjunction with loopback UDP transmission (CVE-2017-6347).

The hashbin_delete function in net/irda/irqueue.c in the Linux kernel before 4.9.13 improperly manages lock dropping, which allows local users to cause a denial of service (deadlock) via crafted operations on IrDA devices (CVE-2017-6348).

For other upstream fixes in this update, see the referenced changelogs.