Red Hat Security Advisory: kernel security and bug fix update

Important

In the Linux kernel, the following vulnerability has been resolved: writeback: avoid use-after-free after removing device When a disk is removed, bdi_unregister gets called to stop further writeback and wait for associated delayed work to complete. However, wb_inode_writeback_end() may schedule bandwidth estimation dwork after this has completed, which can result in the timer attempting to access the just freed bdi_writeback. Fix this by checking if the bdi_writeback is alive, similar to when scheduling writeback work. Since this requires wb->work_lock, and wb_inode_writeback_end() may get called from interrupt, switch wb->work_lock to an irqsafe lock.

CWE-825 - Expired Pointer Dereference

A vulnerabilty was found in Linux Kernel, where a speculative pointer dereference problem exists in the Linux Kernel on the do_prlimit() function. The resource argument value is controlled and is used in pointer arithmetic for the 'rlim' variable and can be used to leak the contents.

CWE-476 - NULL Pointer Dereference

A memory corruption flaw was found in the Linux kernel’s human interface device (HID) subsystem in how a user inserts a malicious USB device. This flaw allows a local user to crash or potentially escalate their privileges on the system.

CWE-787 - Out-of-bounds Write

A memory leak flaw was found in the Linux kernel's TLS protocol. This issue could allow a local user unauthorized access to some memory.

CWE-843 - Access of Resource Using Incompatible Type ('Type Confusion')