CVE-2015-7312

This kernel update provides an upgrade to the upstream 4.1 longterm kernel series, currently based on 4.1.8 and resolves at least the following security issues:

It was found that the Linux kernel's keyring implementation would leak memory when adding a key to a keyring via the add_key() function. A local attacker could use this flaw to exhaust all available memory on the system. (CVE-2015-1333)

A flaw was found in the Linux kernel where the deletion of a file or directory could trigger an unmount and reveal data under a mount point. This flaw was inadvertently introduced with the new feature of being able to lazily unmount a mount tree when using file system user namespaces. (CVE-2015-4176)

A flaw was discovered in the kernel's collect_mounts function. If the kernel audit subsystem called collect_mounts to audit an unmounted path, it could panic the system. With this flaw, an unprivileged user could call umount (MNT_DETACH) to launch a denial-of-service attack. (CVE-2015-4177)

A flaw was found in the Linux kernel which is related to the user namespace lazily unmounting file systems. The fs_pin struct has two members (m_list and s_list) which are usually initialized on use in the pin_insert_group function. However, these members might go unmodified; in this case, the system panics when it attempts to destroy or free them. This flaw could be used to launch a denial-of-service attack. (CVE-2015-4178)

A DoS flaw was found for a Linux kernel built for the x86 architecture which had the KVM virtualization support(CONFIG_KVM) enabled. The kernel would be vulnerable to a NULL pointer dereference flaw in Linux kernel's kvm_apic_has_events() function while doing an ioctl. An unprivileged user able to access the "/dev/kvm" device could use this flaw to crash the system kernel. (CVE-2015-4692)

A flaw was found in the kernel's implementation of the Berkeley Packet Filter (BPF). A local attacker could craft BPF code to crash the system by creating a situation in which the JIT compiler would fail to correctly optimize the JIT image on the last pass. This would lead to the CPU executing instructions that were not part of the JIT code. (CVE-2015-4700)

The get_bitmap_file function in drivers/md/md.c in the Linux kernel before 4.1.6 does not initialize a certain bitmap data structure, which allows local users to obtain sensitive information from kernel memory via a GET_BITMAP_FILE ioctl call. (CVE-2015-5697)

Use-after-free vulnerability in the path_openat function in fs/namei.c in the Linux kernel 3.x and 4.x before 4.0.4 allows local users to cause a denial of service or possibly have unspecified other impact via O_TMPFILE filesystem operations that leverage a duplicate cleanup operation. (CVE-2015-5706)

It was discovered that an integer overflow error existed in the SCSIgeneric (sg) driver in the Linux kernel. A local attacker with writepermission to a SCSI generic device could use this to cause a denial of service (system crash) or potentially escalate their privileges. (CVE-2015-5707)

Additionally the following packages have been updated to add or improve support for the 4.1 series kernels: btrfs-progs, iproute2, xtables-addons, nvidia304, nvidia340, kernel-firmware-nonfree, radeon-firmware.

For other changes, see the referenced changelogs:

This kernel-tmb update provides an upgrade to the upstream 4.1 longterm kernel series, currently based on 4.1.15 and resolves at least the following security issues:

It was found that the Linux kernel's keyring implementation would leak memory when adding a key to a keyring via the add_key() function. A local attacker could use this flaw to exhaust all available memory on the system. (CVE-2015-1333)

A flaw was found in the Linux kernel where the deletion of a file or directory could trigger an unmount and reveal data under a mount point. This flaw was inadvertently introduced with the new feature of being able to lazily unmount a mount tree when using file system user namespaces. (CVE-2015-4176)

A flaw was discovered in the kernel's collect_mounts function. If the kernel audit subsystem called collect_mounts to audit an unmounted path, it could panic the system. With this flaw, an unprivileged user could call umount (MNT_DETACH) to launch a denial-of-service attack. (CVE-2015-4177)

A flaw was found in the Linux kernel which is related to the user namespace lazily unmounting file systems. The fs_pin struct has two members (m_list and s_list) which are usually initialized on use in the pin_insert_group function. However, these members might go unmodified; in this case, the system panics when it attempts to destroy or free them. This flaw could be used to launch a denial-of-service attack. (CVE-2015-4178)

A DoS flaw was found for a Linux kernel built for the x86 architecture which had the KVM virtualization support(CONFIG_KVM) enabled. The kernel would be vulnerable to a NULL pointer dereference flaw in Linux kernel's kvm_apic_has_events() function while doing an ioctl. An unprivileged user able to access the "/dev/kvm" device could use this flaw to crash the system kernel. (CVE-2015-4692)

A flaw was found in the kernel's implementation of the Berkeley Packet Filter (BPF). A local attacker could craft BPF code to crash the system by creating a situation in which the JIT compiler would fail to correctly optimize the JIT image on the last pass. This would lead to the CPU executing instructions that were not part of the JIT code. (CVE-2015-4700)

The virtnet_probe function in drivers/net/virtio_net.c in the Linux kernel before 4.2 attempts to support a FRAGLIST feature without proper memory allocation, which allows guest OS users to cause a denial of service (buffer overflow and memory corruption) via a crafted sequence of fragmented packets. (CVE-2015-5156)

Moein Ghasemzadeh discovered that the USB WhiteHEAT serial driver contained hardcoded attributes about the USB devices. An attacker could construct a fake WhiteHEAT USB device that, when inserted, causes a denial of service (system crash) (CVE-2015-5257).

A guest to host DoS issue was found affecting various hypervisors. In that, a guest can DoS the host by triggering an infinite stream of "alignment check" (#AC) exceptions. This causes the microcode to enter an infinite loop where the core never receives another interrupt. The host kernel panics due to this effect (CVE-2015-5307).

The get_bitmap_file function in drivers/md/md.c in the Linux kernel before 4.1.6 does not initialize a certain bitmap data structure, which allows local users to obtain sensitive information from kernel memory via a GET_BITMAP_FILE ioctl call. (CVE-2015-5697)

Use-after-free vulnerability in the path_openat function in fs/namei.c in the Linux kernel 3.x and 4.x before 4.0.4 allows local users to cause a denial of service or possibly have unspecified other impact via O_TMPFILE filesystem operations that leverage a duplicate cleanup operation. (CVE-2015-5706)

It was discovered that an integer overflow error existed in the SCSIgeneric (sg) driver in the Linux kernel. A local attacker with writepermission to a SCSI generic device could use this to cause a denial of service (system crash) or potentially escalate their privileges. (CVE-2015-5707)

The __rds_conn_create function in…

Multiple race conditions in the Advanced Union Filesystem (aufs) aufs3-mmap.patch and aufs4-mmap.patch patches for the Linux kernel 3.x and 4.x allow local users to cause a denial of service (use-after-free and BUG) or possibly gain privileges via a (1) madvise or (2) msync system call, related to mm/madvise.c and mm/msync.c.

It was discovered that the Linux kernel did not check if a new IPv6 MTU set by a user space application was valid. A remote attacker could forge a route advertisement with an invalid MTU that a user space daemon like NetworkManager would honor and apply to the kernel, causing a denial of service. (CVE-2015-0272)

It was discovered that virtio networking in the Linux kernel did not handle fragments correctly, leading to kernel memory corruption. A remote attacker could use this to cause a denial of service (system crash) or possibly execute code with administrative privileges. (CVE-2015-5156)

It was discovered that the Reliable Datagram Sockets (RDS) implementation in the Linux kernel did not verify sockets were properly bound before attempting to send a message, which could cause a NULL pointer dereference. An attacker could use this to cause a denial of service (system crash). (CVE-2015-6937)

Ben Hutchings discovered that the Advanced Union Filesystem (aufs) for the Linux kernel did not correctly handle references of memory mapped files from an aufs mount. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code with administrative privileges. (CVE-2015-7312)

It was discovered that virtio networking in the Linux kernel did not handle fragments correctly, leading to kernel memory corruption. A remote attacker could use this to cause a denial of service (system crash) or possibly execute code with administrative privileges. (CVE-2015-5156)

Benjamin Randazzo discovered an information leak in the md (multiple device) driver when the bitmap_info.file is disabled. A local privileged attacker could use this to obtain sensitive information from the kernel. (CVE-2015-5697)

Marc-André Lureau discovered that the vhost driver did not properly release the userspace provided log file descriptor. A privileged attacker could use this to cause a denial of service (resource exhaustion). (CVE-2015-6252)

It was discovered that the Reliable Datagram Sockets (RDS) implementation in the Linux kernel did not verify sockets were properly bound before attempting to send a message, which could cause a NULL pointer dereference. An attacker could use this to cause a denial of service (system crash). (CVE-2015-6937)

Ben Hutchings discovered that the Advanced Union Filesystem (aufs) for the Linux kernel did not correctly handle references of memory mapped files from an aufs mount. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code with administrative privileges. (CVE-2015-7312)

It was discovered that the Linux kernel did not check if a new IPv6 MTU set by a user space application was valid. A remote attacker could forge a route advertisement with an invalid MTU that a user space daemon like NetworkManager would honor and apply to the kernel, causing a denial of service. (CVE-2015-0272)

It was discovered that virtio networking in the Linux kernel did not handle fragments correctly, leading to kernel memory corruption. A remote attacker could use this to cause a denial of service (system crash) or possibly execute code with administrative privileges. (CVE-2015-5156)

It was discovered that the Reliable Datagram Sockets (RDS) implementation in the Linux kernel did not verify sockets were properly bound before attempting to send a message, which could cause a NULL pointer dereference. An attacker could use this to cause a denial of service (system crash). (CVE-2015-6937)

Ben Hutchings discovered that the Advanced Union Filesystem (aufs) for the Linux kernel did not correctly handle references of memory mapped files from an aufs mount. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code with administrative privileges. (CVE-2015-7312)