CVE-2018-15594

arch/x86/kernel/paravirt.c in the Linux kernel before 4.18.1 mishandles certain indirect calls, which makes it easier for attackers to conduct Spectre-v2 attacks against paravirtual guests.

The SUSE Linux Enterprise 11 SP4 kernel was updated to receive various security and bugfixes.

The following security bugs were fixed:

• CVE-2018-14617: Prevent NULL pointer dereference and panic in hfsplus_lookup() when opening a file (that is purportedly a hard link) in an hfs+ filesystem that has malformed catalog data, and is mounted read-only without a metadata directory (bsc#1102870).
• CVE-2018-16276: Incorrect bounds checking in the yurex USB driver in yurex_read allowed local attackers to use user access read/writes to crash the kernel or potentially escalate privileges (bsc#1106095).
• CVE-2018-15594: Ensure correct handling of indirect calls, to prevent attackers for conducting Spectre-v2 attacks against paravirtual guests (bsc#1105348).
• CVE-2018-14634: Prevent integer overflow in create_elf_tables that allowed a local attacker to exploit this vulnerability via a SUID-root binary and obtain full root privileges (bsc#1108912)
• CVE-2018-12896: Prevent integer overflow in the POSIX timer code that was caused by the way the overrun accounting works. Depending on interval and expiry time values, the overrun can be larger than INT_MAX, but the accounting is int based. This basically made the accounting values, which are visible to user space via timer_getoverrun(2) and siginfo::si_overrun, random. This allowed a local user to cause a denial of service (signed integer overflow) via crafted mmap, futex, timer_create, and timer_settime system calls (bnc#1099922)
• CVE-2018-10940: The cdrom_ioctl_media_changed function allowed local attackers to use a incorrect bounds check in the CDROM driver CDROM_MEDIA_CHANGED ioctl to read out kernel memory (bsc#1092903)
• CVE-2018-16658: Prevent information leak in cdrom_ioctl_drive_status that could have been used by local attackers to read kernel memory (bnc#1107689)
• CVE-2018-6555: The irda_setsockopt function allowed local users to cause a denial of service (ias_object use-after-free and system crash) or possibly have unspecified other impact via an AF_IRDA socket (bnc#1106511)
• CVE-2018-6554: Prevent memory leak in the irda_bind function that allowed local users to cause a denial of service (memory consumption) by repeatedly binding an AF_IRDA socket (bnc#1106509)
• CVE-2018-15572: The spectre_v2_select_mitigation function did not always fill RSB upon a context switch, which made it easier for attackers to conduct userspace-userspace spectreRSB attacks (bnc#1102517)
• CVE-2018-10902: Protect against concurrent access to prevent double realloc (double free) in snd_rawmidi_input_params() and snd_rawmidi_output_status(). A malicious local attacker could have used this for privilege escalation (bnc#1105322)
• CVE-2018-14734: ucma_leave_multicast accessed a certain data structure after a cleanup step in ucma_process_join, which allowed attackers to cause a denial of service (use-after-free) (bsc#1103119)

The following non-security bugs were fixed:

• ACPI: APEI / ERST: Fix missing error handling in erst_reader() (bsc#1045538).
• ALSA: fm801: propagate TUNER_ONLY bit when autodetected (bsc#1045538).
• ALSA: pcm: Fix snd_pcm_hw_params struct copy in compat mode (bsc#1045538).
• ALSA: pcm: Use dma_bytes as size parameter in dma_mmap_coherent() (bsc#1045538).
• ALSA: pcm: fix fifo_size frame calculation (bsc#1045538).
• ALSA: snd-aoa: add of_node_put() in error path (bsc#1045538).
• ALSA: usb-audio: Add sanity checks in v2 clock parsers (bsc#1045538).
• ALSA: usb-audio: Add sanity checks to FE parser (bsc#1045538).
• ALSA: usb-audio: Fix UAC2 get_ctl request with a RANGE attribute (bsc#1045538).
• ALSA: usb-audio: Fix bogus error return in snd_usb_create_stream() (bsc#1045538).
• ALSA: usb-audio: Fix parameter block size for UAC2 control requests (bsc#1045538).
• ALSA: usb-audio: Fix parsing descriptor of UAC2 processing unit (bsc#1045538).
• ALSA: usb-audio: Fix potential out-of-bound access at parsing SU (bsc#1045538). -…

The SUSE Linux Enterprise 12 SP2 LTSS kernel was updated to receive various security and bugfixes.

• CVE-2018-10853: A flaw was found in the way the KVM hypervisor emulated instructions such as sgdt/sidt/fxsave/fxrstor. It did not check current privilege(CPL) level while emulating unprivileged instructions. An unprivileged guest user/process could use this flaw to potentially escalate privileges inside guest (bnc#1097104).
• CVE-2018-10876: A flaw was found in Linux kernel in the ext4 filesystem code. A use-after-free is possible in ext4_ext_remove_space() function when mounting and operating a crafted ext4 image. (bnc#1099811)
• CVE-2018-10877: Linux kernel ext4 filesystem is vulnerable to an out-of-bound access in the ext4_ext_drop_refs() function when operating on a crafted ext4 filesystem image. (bnc#1099846)
• CVE-2018-10878: A flaw was found in the Linux kernel's ext4 filesystem. A local user can cause an out-of-bounds write and a denial of service or unspecified other impact is possible by mounting and operating a crafted ext4 filesystem image. (bnc#1099813)
• CVE-2018-10879: A flaw was found in the Linux kernel's ext4 filesystem. A local user can cause a use-after-free in ext4_xattr_set_entry function and a denial of service or unspecified other impact may occur by renaming a file in a crafted ext4 filesystem image. (bnc#1099844)
• CVE-2018-10880: Linux kernel is vulnerable to a stack-out-of-bounds write in the ext4 filesystem code when mounting and writing to a crafted ext4 image in ext4_update_inline_data(). An attacker could use this to cause a system crash and a denial of service. (bnc#1099845)
• CVE-2018-10881: A flaw was found in the Linux kernel's ext4 filesystem. A local user can cause an out-of-bound access in ext4_get_group_info function, a denial of service, and a system crash by mounting and operating on a crafted ext4 filesystem image. (bnc#1099864)
• CVE-2018-10882: A flaw was found in the Linux kernel's ext4 filesystem. A local user can cause an out-of-bound write in in fs/jbd2/transaction.c code, a denial of service, and a system crash by unmounting a crafted ext4 filesystem image. (bnc#1099849)
• CVE-2018-10883: A flaw was found in the Linux kernel's ext4 filesystem. A local user can cause an out-of-bounds write in jbd2_journal_dirty_metadata(), a denial of service, and a system crash by mounting and operating on a crafted ext4 filesystem image. (bnc#1099863)
• CVE-2018-10902: It was found that the raw midi kernel driver did not protect against concurrent access which leads to a double realloc (double free) in snd_rawmidi_input_params() and snd_rawmidi_output_status() which are part of snd_rawmidi_ioctl() handler in rawmidi.c file. A malicious local attacker could possibly use this for privilege escalation (bnc#1105322).
• CVE-2018-10938: A crafted network packet sent remotely by an attacker may force the kernel to enter an infinite loop in the cipso_v4_optptr() function in net/ipv4/cipso_ipv4.c leading to a denial-of-service. A certain non-default configuration of LSM (Linux Security Module) and NetLabel should be set up on a system before an attacker could leverage this flaw (bnc#1106016).
• CVE-2018-10940: The cdrom_ioctl_media_changed function in drivers/cdrom/cdrom.c allowed local attackers to use a incorrect bounds check in the CDROM driver CDROM_MEDIA_CHANGED ioctl to read out kernel memory (bnc#1092903).
• CVE-2018-12896: An Integer Overflow in kernel/time/posix-timers.c in the POSIX timer code is caused by the way the overrun accounting works. Depending on interval and expiry time values, the overrun can be larger than INT_MAX, but the accounting is int based. This basically made the accounting values, which are visible to user space via timer_getoverrun(2) and siginfo::si_overrun, random. For example, a local user can cause a denial of service (signed integer overflow) via crafted mmap, futex, timer_create, and timer_settime system calls (bnc#1099922).
• CVE-2018-13093: There is a NULL…

The SUSE Linux Enterprise 11 SP4 RT kernel was updated to receive various security and bugfixes.

The following security bugs were fixed:

• CVE-2018-14634: Prevent integer overflow in create_elf_tables that allowed a local attacker to exploit this vulnerability via a SUID-root binary and obtain full root privileges (bsc#1108912)
• CVE-2018-14617: Prevent NULL pointer dereference and panic in hfsplus_lookup() when opening a file (that is purportedly a hard link) in an hfs+ filesystem that has malformed catalog data, and is mounted read-only without a metadata directory (bsc#1102870)
• CVE-2018-16276: Incorrect bounds checking in the yurex USB driver in yurex_read allowed local attackers to use user access read/writes to crash the kernel or potentially escalate privileges (bsc#1106095)
• CVE-2018-12896: Prevent integer overflow in the POSIX timer code that was caused by the way the overrun accounting works. Depending on interval and expiry time values, the overrun can be larger than INT_MAX, but the accounting is int based. This basically made the accounting values, which are visible to user space via timer_getoverrun(2) and siginfo::si_overrun, random. This allowed a local user to cause a denial of service (signed integer overflow) via crafted mmap, futex, timer_create, and timer_settime system calls (bnc#1099922)
• CVE-2018-10940: The cdrom_ioctl_media_changed function allowed local attackers to use a incorrect bounds check in the CDROM driver CDROM_MEDIA_CHANGED ioctl to read out kernel memory (bsc#1092903)
• CVE-2018-16658: Prevent information leak in cdrom_ioctl_drive_status that could have been used by local attackers to read kernel memory (bnc#1107689)
• CVE-2018-6555: The irda_setsockopt function allowed local users to cause a denial of service (ias_object use-after-free and system crash) or possibly have unspecified other impact via an AF_IRDA socket (bnc#1106511)
• CVE-2018-6554: Prevent memory leak in the irda_bind function that allowed local users to cause a denial of service (memory consumption) by repeatedly binding an AF_IRDA socket (bnc#1106509)
• CVE-2018-15594: Ensure correct handling of indirect calls, to prevent attackers for conducting Spectre-v2 attacks against paravirtual guests (bsc#1105348)
• CVE-2018-15572: The spectre_v2_select_mitigation function did not always fill RSB upon a context switch, which made it easier for attackers to conduct userspace-userspace spectreRSB attacks (bnc#1102517)
• CVE-2018-10902: Protect against concurrent access to prevent double realloc (double free) in snd_rawmidi_input_params() and snd_rawmidi_output_status(). A malicious local attacker could have used this for privilege escalation (bnc#1105322).
• CVE-2018-14734: ucma_leave_multicast accessed a certain data structure after a cleanup step in ucma_process_join, which allowed attackers to cause a denial of service (use-after-free) (bsc#1103119)

The following non-security bugs were fixed:

• ACPI: APEI / ERST: Fix missing error handling in erst_reader() (bsc#1045538).
• ALSA: fm801: propagate TUNER_ONLY bit when autodetected (bsc#1045538).
• ALSA: pcm: Fix snd_pcm_hw_params struct copy in compat mode (bsc#1045538).
• ALSA: pcm: Use dma_bytes as size parameter in dma_mmap_coherent() (bsc#1045538).
• ALSA: pcm: fix fifo_size frame calculation (bsc#1045538).
• ALSA: snd-aoa: add of_node_put() in error path (bsc#1045538).
• ALSA: usb-audio: Add sanity checks in v2 clock parsers (bsc#1045538).
• ALSA: usb-audio: Add sanity checks to FE parser (bsc#1045538).
• ALSA: usb-audio: Fix UAC2 get_ctl request with a RANGE attribute (bsc#1045538).
• ALSA: usb-audio: Fix bogus error return in snd_usb_create_stream() (bsc#1045538).
• ALSA: usb-audio: Fix parameter block size for UAC2 control requests (bsc#1045538).
• ALSA: usb-audio: Fix parsing descriptor of UAC2 processing unit (bsc#1045538).
• ALSA: usb-audio: Fix potential out-of-bound access at parsing SU (bsc#1045538). -…

The SUSE Linux Enterprise 12 SP3 kernel was updated to 4.4.178 to receive various security and bugfixes.

Four new speculative execution issues have been identified in Intel CPUs. (bsc#1111331)

• CVE-2018-12126: Microarchitectural Store Buffer Data Sampling (MSBDS)
• CVE-2018-12127: Microarchitectural Fill Buffer Data Sampling (MFBDS)
• CVE-2018-12130: Microarchitectural Load Port Data Samling (MLPDS)
• CVE-2019-11091: Microarchitectural Data Sampling Uncacheable Memory (MDSUM)

This kernel update contains software mitigations, utilizing CPU microcode updates shipped in parallel.

For more information on this set of information leaks, check out https://www.suse.com/support/kb/doc/?id=7023736

The following security issues fixed:

• CVE-2018-5814: Multiple race condition errors when handling probe, disconnect, and rebind operations could be exploited to trigger a use-after-free condition or a NULL pointer dereference by sending multiple USB over IP packets (bnc#1096480).
• CVE-2018-1000204: Prevent infoleak caused by incorrect handling of the SG_IO ioctl (bsc#1096728)
• CVE-2018-10853: A flaw was found in the way the KVM hypervisor emulated instructions such as sgdt/sidt/fxsave/fxrstor. It did not check current privilege(CPL) level while emulating unprivileged instructions. An unprivileged guest user/process could use this flaw to potentially escalate privileges inside guest (bnc#1097104).
• CVE-2018-15594: arch/x86/kernel/paravirt.c mishandled certain indirect calls, which made it easier for attackers to conduct Spectre-v2 attacks against paravirtual guests (bnc#1105348).
• CVE-2019-9503: A brcmfmac frame validation bypass was fixed (bnc#1132828).
• CVE-2019-3882: A flaw was fixed in the vfio interface implementation that permitted violation of the user's locked memory limit. If a device is bound to a vfio driver, such as vfio-pci, and the local attacker is administratively granted ownership of the device, it may cause a system memory exhaustion and thus a denial of service (DoS). Versions 3.10, 4.14 and 4.18 are vulnerable (bnc#1131416 bnc#1131427).

The following non-security bugs were fixed:

• 9p/net: fix memory leak in p9_client_create (bnc#1012382).
• 9p: use inode->i_lock to protect i_size_write() under 32-bit (bnc#1012382).
• acpi: acpi_pad: Do not launch acpi_pad threads on idle cpus (bsc#1113399).
• acpi / bus: Only call dmi_check_system() on X86 (git-fixes).
• acpi / button: make module loadable when booted in non-ACPI mode (bsc#1051510).
• acpi / device_sysfs: Avoid OF modalias creation for removed device (bnc#1012382).
• acpi: include ACPI button driver in base kernel (bsc#1062056).
• Add hlist_add_tail_rcu() (Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net) (bnc#1012382).
• alsa: bebob: use more identical mod_alias for Saffire Pro 10 I/O against Liquid Saffire 56 (bnc#1012382).
• alsa: compress: add support for 32bit calls in a 64bit kernel (bnc#1012382).
• alsa: compress: prevent potential divide by zero bugs (bnc#1012382).
• alsa: hda - Enforces runtime_resume after S3 and S4 for each codec (bnc#1012382).
• alsa: hda - Record the current power state before suspend/resume calls (bnc#1012382).
• alsa: pcm: Do not suspend stream in unrecoverable PCM state (bnc#1012382).
• alsa: pcm: Fix possible OOB access in PCM oss plugins (bnc#1012382).
• alsa: rawmidi: Fix potential Spectre v1 vulnerability (bnc#1012382).
• alsa: seq: oss: Fix Spectre v1 vulnerability (bnc#1012382).
• applicom: Fix potential Spectre v1 vulnerabilities (bnc#1012382).
• arc: fix __ffs return value to avoid build warnings (bnc#1012382).
• arc: uacces: remove lp_start, lp_end from clobber list (bnc#1012382).
• arcv2: Enable unaligned access in early ASM code (bnc#1012382).
• arm64: fix COMPAT_SHMLBA definition for large pages (bnc#1012382).
• arm64: Fix NUMA build error when !CONFIG_ACPI (fate#319981, git-fixes).
• arm64: Fix NUMA build error when !CONFIG_ACPI (git-fixes).
• arm64: hide _efistub aliases from kallsyms…

It was discovered that the paravirtualization implementation in the Linux kernel did not properly handle some indirect calls, reducing the effectiveness of Spectre v2 mitigations for paravirtual guests. A local attacker could use this to expose sensitive information. (CVE-2018-15594)

It was discovered that microprocessors utilizing speculative execution and prediction of return addresses via Return Stack Buffer (RSB) may allow unauthorized memory reads via sidechannel attacks. An attacker could use this to expose sensitive information. (CVE-2018-15572)

It was discovered that an integer overflow vulnerability existed in the Linux kernel when loading an executable to run. A local attacker could use this to gain administrative privileges. (CVE-2018-14634)

It was discovered that a stack-based buffer overflow existed in the iSCSI target implementation of the Linux kernel. A remote attacker could use this to cause a denial of service (system crash). (CVE-2018-14633)

It was discovered that a memory leak existed in the IRDA subsystem of the Linux kernel. A local attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2018-6554)

It was discovered that a use-after-free vulnerability existed in the IRDA implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-6555)

Jann Horn discovered that the vmacache subsystem did not properly handle sequence number overflows, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2018-17182)

It was discovered that the paravirtualization implementation in the Linux kernel did not properly handle some indirect calls, reducing the effectiveness of Spectre v2 mitigations for paravirtual guests. A local attacker could use this to expose sensitive information. (CVE-2018-15594)

It was discovered that microprocessors utilizing speculative execution and prediction of return addresses via Return Stack Buffer (RSB) may allow unauthorized memory reads via sidechannel attacks. An attacker could use this to expose sensitive information. (CVE-2018-15572)

It was discovered that a NULL pointer dereference could be triggered in the OCFS2 file system implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-18216)

It was discovered that a race condition existed in the raw MIDI driver for the Linux kernel, leading to a double free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10902)

It was discovered that a stack-based buffer overflow existed in the iSCSI target implementation of the Linux kernel. A remote attacker could use this to cause a denial of service (system crash). (CVE-2018-14633)

It was discovered that the YUREX USB device driver for the Linux kernel did not properly restrict user space reads or writes. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-16276)

It was discovered that a memory leak existed in the IRDA subsystem of the Linux kernel. A local attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2018-6554)

It was discovered that a use-after-free vulnerability existed in the IRDA implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-6555)

USN-3776-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 16.04 LTS for Ubuntu 14.04 LTS.

Jann Horn discovered that the vmacache subsystem did not properly handle sequence number overflows, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2018-17182)

It was discovered that the paravirtualization implementation in the Linux kernel did not properly handle some indirect calls, reducing the effectiveness of Spectre v2 mitigations for paravirtual guests. A local attacker could use this to expose sensitive information. (CVE-2018-15594)

It was discovered that microprocessors utilizing speculative execution and prediction of return addresses via Return Stack Buffer (RSB) may allow unauthorized memory reads via sidechannel attacks. An attacker could use this to expose sensitive information. (CVE-2018-15572)

It was discovered that a NULL pointer dereference could be triggered in the OCFS2 file system implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-18216)

It was discovered that a race condition existed in the raw MIDI driver for the Linux kernel, leading to a double free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10902)

It was discovered that a stack-based buffer overflow existed in the iSCSI target implementation of the Linux kernel. A remote attacker could use this to cause a denial of service (system crash). (CVE-2018-14633)

It was discovered that the YUREX USB device driver for the Linux kernel did not properly restrict user space reads or writes. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-16276)

It was discovered that a memory leak existed in the IRDA subsystem of the Linux kernel. A local attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2018-6554)

It was discovered that a use-after-free vulnerability existed in the IRDA implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-6555)

Jann Horn discovered that the vmacache subsystem did not properly handle sequence number overflows, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2018-17182)

It was discovered that the paravirtualization implementation in the Linux kernel did not properly handle some indirect calls, reducing the effectiveness of Spectre v2 mitigations for paravirtual guests. A local attacker could use this to expose sensitive information. (CVE-2018-15594)

It was discovered that microprocessors utilizing speculative execution and prediction of return addresses via Return Stack Buffer (RSB) may allow unauthorized memory reads via sidechannel attacks. An attacker could use this to expose sensitive information. (CVE-2018-15572)

Andy Lutomirski and Mika Penttilä discovered that the KVM implementation in the Linux kernel did not properly check privilege levels when emulating some instructions. An unprivileged attacker in a guest VM could use this to escalate privileges within the guest. (CVE-2018-10853)

It was discovered that a stack-based buffer overflow existed in the iSCSI target implementation of the Linux kernel. A remote attacker could use this to cause a denial of service (system crash). (CVE-2018-14633)

It was discovered that a memory leak existed in the IRDA subsystem of the Linux kernel. A local attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2018-6554)

It was discovered that a use-after-free vulnerability existed in the IRDA implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-6555)

USN 3652-1 added a mitigation for Speculative Store Bypass a.k.a. Spectre Variant 4 (CVE-2018-3639). This update provides the corresponding mitigation for ARM64 processors. Please note that for this mitigation to be effective, an updated firmware for the processor may be required.

USN-3777-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 18.04 LTS for Ubuntu 16.04 LTS.

Jann Horn discovered that the vmacache subsystem did not properly handle sequence number overflows, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2018-17182)

It was discovered that the paravirtualization implementation in the Linux kernel did not properly handle some indirect calls, reducing the effectiveness of Spectre v2 mitigations for paravirtual guests. A local attacker could use this to expose sensitive information. (CVE-2018-15594)

It was discovered that microprocessors utilizing speculative execution and prediction of return addresses via Return Stack Buffer (RSB) may allow unauthorized memory reads via sidechannel attacks. An attacker could use this to expose sensitive information. (CVE-2018-15572)

Andy Lutomirski and Mika Penttilä discovered that the KVM implementation in the Linux kernel did not properly check privilege levels when emulating some instructions. An unprivileged attacker in a guest VM could use this to escalate privileges within the guest. (CVE-2018-10853)

It was discovered that a stack-based buffer overflow existed in the iSCSI target implementation of the Linux kernel. A remote attacker could use this to cause a denial of service (system crash). (CVE-2018-14633)

It was discovered that a memory leak existed in the IRDA subsystem of the Linux kernel. A local attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2018-6554)

It was discovered that a use-after-free vulnerability existed in the IRDA implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-6555)

USN 3653-2 added a mitigation for Speculative Store Bypass a.k.a. Spectre Variant 4 (CVE-2018-3639). This update provides the corresponding mitigation for ARM64 processors. Please note that for this mitigation to be effective, an updated firmware for the processor may be required. '

USN-3777-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04 %LTS. This update provides the corresponding updates for the Linux kernel for Azure Cloud systems.

Jann Horn discovered that the vmacache subsystem did not properly handle sequence number overflows, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2018-17182)

It was discovered that the paravirtualization implementation in the Linux kernel did not properly handle some indirect calls, reducing the effectiveness of Spectre v2 mitigations for paravirtual guests. A local attacker could use this to expose sensitive information. (CVE-2018-15594)

It was discovered that microprocessors utilizing speculative execution and prediction of return addresses via Return Stack Buffer (RSB) may allow unauthorized memory reads via sidechannel attacks. An attacker could use this to expose sensitive information. (CVE-2018-15572)

Jann Horn discovered that microprocessors utilizing speculative execution and branch prediction may allow unauthorized memory reads via sidechannel attacks. This flaw is known as Spectre. A local attacker could use this to expose sensitive information, including kernel memory. (CVE-2017-5715)

It was discovered that a stack-based buffer overflow existed in the iSCSI target implementation of the Linux kernel. A remote attacker could use this to cause a denial of service (system crash). (CVE-2018-14633)

Jann Horn and Ken Johnson discovered that microprocessors utilizing speculative execution of a memory read may allow unauthorized memory reads via a sidechannel attack. This flaw is known as Spectre Variant 4. A local attacker could use this to expose sensitive information, including kernel memory. (CVE-2018-3639)

It was discovered that a memory leak existed in the IRDA subsystem of the Linux kernel. A local attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2018-6554)

It was discovered that a use-after-free vulnerability existed in the IRDA implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-6555)