SUSE-SU-2021:3935-1

The SUSE Linux Enterprise 12 SP3 LTSS kernel was updated to receive various security and bugfixes.

The following security bugs were fixed:

• Unprivileged BPF has been disabled by default to reduce attack surface as too many security issues have happened in the past (jsc#SLE-22573)

  You can reenable via systemctl setting /proc/sys/kernel/unprivileged_bpf_disabled to 0. (kernel.unprivileged_bpf_disabled = 0)

• CVE-2021-31916: An out-of-bounds (OOB) memory write flaw was found in list_devices in drivers/md/dm-ioctl.c in the Multi-device driver module in the Linux kernel A bound check failure allowed an attacker with special user (CAP_SYS_ADMIN) privilege to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information. The highest threat from this vulnerability is to system availability (bnc#1192781).

• CVE-2021-20322: Make the ipv4 and ipv6 ICMP exception caches less predictive to avoid information leaks about UDP ports in use. (bsc#1191790)

• CVE-2021-34981: Fixed file refcounting in cmtp when cmtp_attach_device fails (bsc#1191961).

• CVE-2020-12655: An issue was discovered in xfs_agf_verify in fs/xfs/libxfs/xfs_alloc.c. Attackers may trigger a sync of excessive duration via an XFS v5 image with crafted metadata, aka CID-d0c7feaf8767 (bnc#1171217).

• CVE-2021-43389: There was an array-index-out-of-bounds flaw in the detach_capi_ctr function in drivers/isdn/capi/kcapi.c (bnc#1191958).

• CVE-2021-37159: hso_free_net_device in drivers/net/usb/hso.c called unregister_netdev without checking for the NETREG_REGISTERED state, leading to a use-after-free and a double free (bnc#1188601).

• CVE-2021-34556: An unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because the protection mechanism neglects the possibility of uninitialized memory locations on the BPF stack (bnc#1188983).

• CVE-2021-35477: An unprivileged BPF program can obtain sensitive...