Affecting the long-term supported Linux 4.9 kernel used by the Debian GNU/Linux 9 “Stretch” operating system series, there are a total of 18 security vulnerabilities patched in this major update that have been discovered in the upstream Linux kernel and may lead to information leaks, privilege escalation, or denial of service.
These include a memory leak in the irda_bind function and a flaw in the irda_setsockopt function of Linux kernel’s IrDA subsystem, a flaw in the fd_locked_ioctl function in the Floppy driver, a buffer overflow in the Bluetooth HIDP implementation, and a double-realloc (double free) flaw in the rawmidi kernel driver.
Furthermore, a use-after-free bug and a potential null pointer dereference were discovered in Linux kernel’s F2FS (Flash-Friendly File System) implementation, a potential null pointer dereference in the HFS+ implementation, and a stack-based buffer overflow flaw in the chap_server_compute_md5() function of the iSCSI target code.
The security patch also addresses a use-after-free bug was in Linux kernel’s InfiniBand communication manager, and a variant of the Spectre V2 vulnerability dubbed SpectreRSB. Mitigations are also available for the Spectre Variant 2 flaw for some indirect function calls used in paravirtualised guests.
Security flaws were also discovered in the HID events interface in debugfs, the Cipso IPv4 module, the Linux kernel exit code used on 64-bit (amd64) systems running as Xen PV guests, the yurex driver, the cdrom driver, and a use-after-free flaw in the vmacache_flush_all function.
Submitted by: Arnfried Walbrecht