Linux Kernel

A backporting error was discovered in the Linux stable/longterm kernel 4.4.x through 4.4.190, 4.9.x through 4.9.190, 4.14.x through 4.14.141, 4.19.x through 4.19.69, and 5.2.x through 5.2.11. Misuse of the upstream "x86/ptrace: Fix possible spectre-v1 in ptrace_get_debugreg()" commit reintroduced the Spectre vulnerability that it aimed to eliminate. This occurred because the backport process depends on cherry picking specific commits, and because two (correctly ordered) code lines were swapped.Show less

An issue was discovered in the Linux kernel before 5.0.19. There is an out-of-bounds array access in __xfrm_policy_unlink, which will cause denial of service, because verify_newpolicy_info in net/xfrm/xfrm_user.c mishandles directory validation.Show less

An issue was discovered in xfs_setattr_nonsize in fs/xfs/xfs_iops.c in the Linux kernel through 5.2.9. XFS partially wedges when a chgrp fails on account of being out of disk quota. xfs_setattr_nonsize is failing to unlock the ILOCK after the xfs_qm_vop_chown_reserve call fails. This is primarily a local DoS attack vector, but it might result as well in remote DoS if the XFS filesystem is exported for instance via NFS.Show less

In the Linux kernel, a certain net/ipv4/tcp_output.c change, which was properly incorporated into 4.16.12, was incorrectly backported to the earlier longterm kernels, introducing a new vulnerability that was potentially more severe than the issue that was intended to be fixed by backporting. Specifically, by adding to a write queue between disconnection and re-connection, a local attacker can trigger multiple use-after-free conditions. This can result in a kernel crash, or potentially in privilege escalation. NOTE: this affects (for example) Linux distributions that use 4.9.x longterm kernels before 4.9.190 or 4.14.x longterm kernels before 4.14.139.Show less