========================================================================== Kernel Live Patch Security Notice LSN-0039-1 May 25, 2018 linux vulnerability ========================================================================== A security issue affects these releases of Ubuntu: | Series | Base kernel | Arch | flavors | |------------------+--------------+----------+------------------| | Ubuntu 14.04 LTS | 4.4.0 | amd64 | generic | | Ubuntu 14.04 LTS | 4.4.0 | amd64 | lowlatency | | Ubuntu 16.04 LTS | 4.4.0 | amd64 | generic | | Ubuntu 16.04 LTS | 4.4.0 | amd64 | lowlatency | | Ubuntu 18.04 LTS | 4.15.0 | amd64 | generic | | Ubuntu 18.04 LTS | 4.15.0 | amd64 | lowlatency | Summary: Several security issues were fixed in the kernel. Software Description: - linux: Linux kernel Details: Alexei Starovoitov discovered that the Berkeley Packet Filter (BPF) implementation in the Linux kernel contained a branch-pruning logic issue around unreachable code. A local attacker could use this to cause a denial of service. (CVE-2017-17862) The ext4_iget function in fs/ext4/inode.c in the Linux kernel through 4.15.15 mishandles the case of a root directory with a zero i_links_count, which allows attackers to cause a denial of service (ext4_process_freed_data NULL pointer dereference and OOPS) via a crafted ext4 image. (CVE-2018-1092) The ext4_valid_block_bitmap function in fs/ext4/balloc.c in the Linux kernel through 4.15.15 allows attackers to cause a denial of service (out-of-bounds read and system crash) via a crafted ext4 image because balloc.c and ialloc.c do not validate bitmap block numbers. (CVE-2018-1093) A memory leak in the hwsim_new_radio_nl function in drivers/net/wireless/mac80211_hwsim.c in the Linux kernel through 4.15.9 allows local users to cause a denial of service (memory consumption) by triggering an out-of-array error case. (CVE-2018-8087) Luo Quan and Wei Yang discovered that a race condition existed in the Advanced Linux Sound Architecture (ALSA) subsystem of the Linux kernel when handling ioctl()s. A local attacker could use this to cause a denial of service (system deadlock). (CVE-2018-1000004) Update instructions: The problem can be corrected by updating your livepatches to the following versions: | Kernel | Version | flavors | |---------------------------+----------+--------------------------| | 4.4.0-124.148 | 39.1 | generic, lowlatency | | lts-4.4.0-124.148~14.04.1 | 39.1 | generic, lowlatency | | 4.15.0-20.21 | 39.3 | generic, lowlatency | Additionally, you should install an updated kernel with these fixes and reboot at your convienience. References: CVE-2017-17862, CVE-2018-1092, CVE-2018-1093, CVE-2018-8087, CVE-2018-1000004 -- ubuntu-security-announce mailing list ubuntu-security-announce@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-security-announce