RHSA-2019:0831 - Security Advisory

Topic

An update for kernel-alt is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

The kernel-alt packages provide the Linux kernel version 4.x.

Security Fix(es):

• kernel: lack of check for mmap minimum address in expand_downwards in mm/mmap.c leads to NULL pointer dereferences exploit on non-SMAP platforms (CVE-2019-9213)
• kernel: use-after-free in ucma_leave_multicast in drivers/infiniband/core/ucma.c (CVE-2018-14734)
• kernel: Unprivileged users able to inspect kernel stacks of arbitrary tasks (CVE-2018-17972)
• kernel: TLB flush happens too late on mremap (CVE-2018-18281)
• kernel: Type confusion in drivers/tty/n_tty.c allows for a denial of service (CVE-2018-18386)
• kernel: userfaultfd bypasses tmpfs file permissions (CVE-2018-18397)
• kernel: Integer overflow in the alarm_timer_nsleep function (CVE-2018-13053)
• kernel: NULL pointer dereference in xfs_da_shrink_inode function (CVE-2018-13094)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Bug Fix(es):

• Failed to boot with ftrace=function in kvm with 2vcpu (BZ#1501024)
• [ALT-7.5][x86_64] perf test 63 - inet_pton fails on x86_64 (BZ#1518836)
• BUG: potential out-of-bounds string access when forcing a SELinux label on a file (BZ#1595706)
• stack out-of-bounds in smb{2,3}_create_lease_buf() on SMB2/SMB3 mounts (BZ#1598757)
• [ALT-7.6][KVM][PANIC] ltp/lite proc01 - Unable to handle kernel paging request at virtual address ffff7fe000200018 (BZ#1623193)
• Kernel lock up due to read/write lock (BZ#1636261)
• [RHEL-ALT] Fix potential Spectre v1 in tty code (BZ#1639679)
• [Huawei AArch64 7.6 Bug] HNS3: Vlan on HNS3 NIC cannot communicate (BZ#1639713)
• [RHEL7.6-ALT][AWS] backport "nvme: update timeout module parameter type" (BZ#1654958)
• ignore STABLE_FLAG of rmap_item->address in rmap_walk_ksm (BZ#1663565)
• RHEL-Alt-7.6 - kernel: zcrypt: fix specification exception on z196 at ap probe (BZ#1670018)
• [Huawei AArch64 7.6 Bug] Flock over NFSv3 failed (BZ#1670650)
• [Huawei AArch64 7.6/7.6-z Bug] HNS3: if a single transmit packet(skb) has more than 8 frags, will cause the NIC to be unavailable (BZ#1677643)
• krb5{,i,p} doesn't work with older enctypes on aarch64 (BZ#1678922)

Users of kernel are advised to upgrade to these updated packages, which fix these bugs.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.

Affected Products

• Red Hat Enterprise Linux for ARM 64 7 aarch64
• Red Hat Enterprise Linux for Power 9 7 ppc64le
• Red Hat Enterprise Linux for IBM System z (Structure A) 7 s390x

Fixes

• BZ - 1597747 - CVE-2018-13053 kernel: Integer overflow in the alarm_timer_nsleep function
• BZ - 1597771 - CVE-2018-13094 kernel: NULL pointer dereference in xfs_da_shrink_inode function
• BZ - 1611005 - CVE-2018-14734 kernel: use-after-free in ucma_leave_multicast in drivers/infiniband/core/ucma.c
• BZ - 1636349 - CVE-2018-17972 kernel: Unprivileged users able to inspect kernel stacks of arbitrary tasks
• BZ - 1640598 - CVE-2018-18386 kernel: Type confusion in drivers/tty/n_tty.c allows for a denial of service
• BZ - 1641548 - CVE-2018-18397 kernel: userfaultfd bypasses tmpfs file permissions
• BZ - 1645121 - CVE-2018-18281 kernel: TLB flush happens too late on mremap
• BZ - 1686136 - CVE-2019-9213 kernel: lack of check for mmap minimum address in expand_downwards in mm/mmap.c leads to NULL pointer dereferences exploit on non-SMAP platforms

CVEs

• CVE-2018-13053
• CVE-2018-13094
• CVE-2018-14734
• CVE-2018-17972
• CVE-2018-18281
• CVE-2018-18386
• CVE-2018-18397
• CVE-2019-9213

References

• https://access.redhat.com/security/updates/classification/#important