RedHat: RHSA-2019-2029:01 Important: kernel security, bug fix,
Summary
The kernel packages contain the Linux kernel, the core of any Linux
operating system.
Security Fix(es):
* Kernel: vhost_net: infinite loop while receiving packets leads to DoS
(CVE-2019-3900)
* Kernel: page cache side channel attacks (CVE-2019-5489)
* kernel: Buffer overflow in hidp_process_report (CVE-2018-9363)
* kernel: l2tp: Race condition between pppol2tp_session_create() and
l2tp_eth_create() (CVE-2018-9517)
* kernel: kvm: guest userspace to guest kernel write (CVE-2018-10853)
* kernel: use-after-free Read in vhost_transport_send_pkt (CVE-2018-14625)
* kernel: use-after-free in ucma_leave_multicast in
drivers/infiniband/core/ucma.c (CVE-2018-14734)
* kernel: Mishandling of indirect calls weakens Spectre mitigation for
paravirtual guests (CVE-2018-15594)
* kernel: TLB flush happens too late on mremap (CVE-2018-18281)
* kernel: Heap address information leak while using L2CAP_GET_CONF_OPT
(CVE-2019-3459)
* kernel: Heap address information leak while using L2CAP_PARSE_CONF_RSP
(CVE-2019-3460)
* kernel: denial of service vector through vfio DMA mappings
(CVE-2019-3882)
* kernel: fix race condition between mmget_not_zero()/get_task_mm() and
core dumping (CVE-2019-11599)
* kernel: a NULL pointer dereference in
drivers/scsi/megaraid/megaraid_sas_base.c leading to DoS (CVE-2019-11810)
* kernel: fs/ext4/extents.c leads to information disclosure
(CVE-2019-11833)
* kernel: Information exposure in fd_locked_ioctl function in
drivers/block/floppy.c (CVE-2018-7755)
* kernel: Memory leak in
drivers/net/wireless/mac80211_hwsim.c:hwsim_new_radio_nl() can lead to
potential denial of service (CVE-2018-8087)
* kernel: HID: debug: Buffer overflow in hid_debug_events_read() in
drivers/hid/hid-debug.c (CVE-2018-9516)
* kernel: Integer overflow in the alarm_timer_nsleep function
(CVE-2018-13053)
* kernel: NULL pointer dereference in lookup_slow function (CVE-2018-13093)
* kernel: NULL pointer dereference in xfs_da_shrink_inode function
(CVE-2018-13094)
* kernel: NULL pointer dereference in fs/xfs/libxfs/xfs_inode_buf.c
(CVE-2018-13095)
* kernel: Information leak in cdrom_ioctl_drive_status (CVE-2018-16658)
* kernel: out-of-bound read in memcpy_fromiovecend() (CVE-2018-16885)
* Kernel: KVM: leak of uninitialized stack contents to guest
(CVE-2019-7222)
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.
Additional Changes:
For detailed information on changes in this release, see the Red Hat
Enterprise Linux 7.7 Release Notes linked from the References section.
Summary
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.
References
https://access.redhat.com/security/cve/CVE-2018-7755 https://access.redhat.com/security/cve/CVE-2018-8087 https://access.redhat.com/security/cve/CVE-2018-9363 https://access.redhat.com/security/cve/CVE-2018-9516 https://access.redhat.com/security/cve/CVE-2018-9517 https://access.redhat.com/security/cve/CVE-2018-10853 https://access.redhat.com/security/cve/CVE-2018-13053 https://access.redhat.com/security/cve/CVE-2018-13093 https://access.redhat.com/security/cve/CVE-2018-13094 https://access.redhat.com/security/cve/CVE-2018-13095 https://access.redhat.com/security/cve/CVE-2018-14625 https://access.redhat.com/security/cve/CVE-2018-14734 https://access.redhat.com/security/cve/CVE-2018-15594 https://access.redhat.com/security/cve/CVE-2018-16658 https://access.redhat.com/security/cve/CVE-2018-16885 https://access.redhat.com/security/cve/CVE-2018-18281 https://access.redhat.com/security/cve/CVE-2019-3459 https://access.redhat.com/security/cve/CVE-2019-3460 https://access.redhat.com/security/cve/CVE-2019-3882 https://access.redhat.com/security/cve/CVE-2019-3900 https://access.redhat.com/security/cve/CVE-2019-5489 https://access.redhat.com/security/cve/CVE-2019-7222 https://access.redhat.com/security/cve/CVE-2019-11599 https://access.redhat.com/security/cve/CVE-2019-11810 https://access.redhat.com/security/cve/CVE-2019-11833 https://access.redhat.com/security/updates/classification/#important https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/7.7_release_notes/index
Package List
Red Hat Enterprise Linux Client (v. 7):
Source:
kernel-3.10.0-1062.el7.src.rpm
noarch:
kernel-abi-whitelists-3.10.0-1062.el7.noarch.rpm
kernel-doc-3.10.0-1062.el7.noarch.rpm
x86_64:
bpftool-3.10.0-1062.el7.x86_64.rpm
bpftool-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-3.10.0-1062.el7.x86_64.rpm
kernel-debug-3.10.0-1062.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debug-devel-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-1062.el7.x86_64.rpm
kernel-devel-3.10.0-1062.el7.x86_64.rpm
kernel-headers-3.10.0-1062.el7.x86_64.rpm
kernel-tools-3.10.0-1062.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-tools-libs-3.10.0-1062.el7.x86_64.rpm
perf-3.10.0-1062.el7.x86_64.rpm
perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
python-perf-3.10.0-1062.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
Red Hat Enterprise Linux Client Optional (v. 7):
x86_64:
bpftool-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-1062.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-tools-libs-devel-3.10.0-1062.el7.x86_64.rpm
perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
Red Hat Enterprise Linux ComputeNode (v. 7):
Source:
kernel-3.10.0-1062.el7.src.rpm
noarch:
kernel-abi-whitelists-3.10.0-1062.el7.noarch.rpm
kernel-doc-3.10.0-1062.el7.noarch.rpm
x86_64:
bpftool-3.10.0-1062.el7.x86_64.rpm
bpftool-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-3.10.0-1062.el7.x86_64.rpm
kernel-debug-3.10.0-1062.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debug-devel-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-1062.el7.x86_64.rpm
kernel-devel-3.10.0-1062.el7.x86_64.rpm
kernel-headers-3.10.0-1062.el7.x86_64.rpm
kernel-tools-3.10.0-1062.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-tools-libs-3.10.0-1062.el7.x86_64.rpm
perf-3.10.0-1062.el7.x86_64.rpm
perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
python-perf-3.10.0-1062.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
Red Hat Enterprise Linux ComputeNode Optional (v. 7):
x86_64:
bpftool-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-1062.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-tools-libs-devel-3.10.0-1062.el7.x86_64.rpm
perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
Red Hat Enterprise Linux Server (v. 7):
Source:
kernel-3.10.0-1062.el7.src.rpm
noarch:
kernel-abi-whitelists-3.10.0-1062.el7.noarch.rpm
kernel-doc-3.10.0-1062.el7.noarch.rpm
ppc64:
bpftool-3.10.0-1062.el7.ppc64.rpm
bpftool-debuginfo-3.10.0-1062.el7.ppc64.rpm
kernel-3.10.0-1062.el7.ppc64.rpm
kernel-bootwrapper-3.10.0-1062.el7.ppc64.rpm
kernel-debug-3.10.0-1062.el7.ppc64.rpm
kernel-debug-debuginfo-3.10.0-1062.el7.ppc64.rpm
kernel-debug-devel-3.10.0-1062.el7.ppc64.rpm
kernel-debuginfo-3.10.0-1062.el7.ppc64.rpm
kernel-debuginfo-common-ppc64-3.10.0-1062.el7.ppc64.rpm
kernel-devel-3.10.0-1062.el7.ppc64.rpm
kernel-headers-3.10.0-1062.el7.ppc64.rpm
kernel-tools-3.10.0-1062.el7.ppc64.rpm
kernel-tools-debuginfo-3.10.0-1062.el7.ppc64.rpm
kernel-tools-libs-3.10.0-1062.el7.ppc64.rpm
perf-3.10.0-1062.el7.ppc64.rpm
perf-debuginfo-3.10.0-1062.el7.ppc64.rpm
python-perf-3.10.0-1062.el7.ppc64.rpm
python-perf-debuginfo-3.10.0-1062.el7.ppc64.rpm
ppc64le:
bpftool-3.10.0-1062.el7.ppc64le.rpm
bpftool-debuginfo-3.10.0-1062.el7.ppc64le.rpm
kernel-3.10.0-1062.el7.ppc64le.rpm
kernel-bootwrapper-3.10.0-1062.el7.ppc64le.rpm
kernel-debug-3.10.0-1062.el7.ppc64le.rpm
kernel-debug-debuginfo-3.10.0-1062.el7.ppc64le.rpm
kernel-debuginfo-3.10.0-1062.el7.ppc64le.rpm
kernel-debuginfo-common-ppc64le-3.10.0-1062.el7.ppc64le.rpm
kernel-devel-3.10.0-1062.el7.ppc64le.rpm
kernel-headers-3.10.0-1062.el7.ppc64le.rpm
kernel-tools-3.10.0-1062.el7.ppc64le.rpm
kernel-tools-debuginfo-3.10.0-1062.el7.ppc64le.rpm
kernel-tools-libs-3.10.0-1062.el7.ppc64le.rpm
perf-3.10.0-1062.el7.ppc64le.rpm
perf-debuginfo-3.10.0-1062.el7.ppc64le.rpm
python-perf-3.10.0-1062.el7.ppc64le.rpm
python-perf-debuginfo-3.10.0-1062.el7.ppc64le.rpm
s390x:
bpftool-3.10.0-1062.el7.s390x.rpm
bpftool-debuginfo-3.10.0-1062.el7.s390x.rpm
kernel-3.10.0-1062.el7.s390x.rpm
kernel-debug-3.10.0-1062.el7.s390x.rpm
kernel-debug-debuginfo-3.10.0-1062.el7.s390x.rpm
kernel-debug-devel-3.10.0-1062.el7.s390x.rpm
kernel-debuginfo-3.10.0-1062.el7.s390x.rpm
kernel-debuginfo-common-s390x-3.10.0-1062.el7.s390x.rpm
kernel-devel-3.10.0-1062.el7.s390x.rpm
kernel-headers-3.10.0-1062.el7.s390x.rpm
kernel-kdump-3.10.0-1062.el7.s390x.rpm
kernel-kdump-debuginfo-3.10.0-1062.el7.s390x.rpm
kernel-kdump-devel-3.10.0-1062.el7.s390x.rpm
perf-3.10.0-1062.el7.s390x.rpm
perf-debuginfo-3.10.0-1062.el7.s390x.rpm
python-perf-3.10.0-1062.el7.s390x.rpm
python-perf-debuginfo-3.10.0-1062.el7.s390x.rpm
x86_64:
bpftool-3.10.0-1062.el7.x86_64.rpm
bpftool-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-3.10.0-1062.el7.x86_64.rpm
kernel-debug-3.10.0-1062.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debug-devel-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-1062.el7.x86_64.rpm
kernel-devel-3.10.0-1062.el7.x86_64.rpm
kernel-headers-3.10.0-1062.el7.x86_64.rpm
kernel-tools-3.10.0-1062.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-tools-libs-3.10.0-1062.el7.x86_64.rpm
perf-3.10.0-1062.el7.x86_64.rpm
perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
python-perf-3.10.0-1062.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
Red Hat Enterprise Linux Server Optional (v. 7):
ppc64:
bpftool-debuginfo-3.10.0-1062.el7.ppc64.rpm
kernel-debug-debuginfo-3.10.0-1062.el7.ppc64.rpm
kernel-debuginfo-3.10.0-1062.el7.ppc64.rpm
kernel-debuginfo-common-ppc64-3.10.0-1062.el7.ppc64.rpm
kernel-tools-debuginfo-3.10.0-1062.el7.ppc64.rpm
kernel-tools-libs-devel-3.10.0-1062.el7.ppc64.rpm
perf-debuginfo-3.10.0-1062.el7.ppc64.rpm
python-perf-debuginfo-3.10.0-1062.el7.ppc64.rpm
ppc64le:
bpftool-debuginfo-3.10.0-1062.el7.ppc64le.rpm
kernel-debug-debuginfo-3.10.0-1062.el7.ppc64le.rpm
kernel-debug-devel-3.10.0-1062.el7.ppc64le.rpm
kernel-debuginfo-3.10.0-1062.el7.ppc64le.rpm
kernel-debuginfo-common-ppc64le-3.10.0-1062.el7.ppc64le.rpm
kernel-tools-debuginfo-3.10.0-1062.el7.ppc64le.rpm
kernel-tools-libs-devel-3.10.0-1062.el7.ppc64le.rpm
perf-debuginfo-3.10.0-1062.el7.ppc64le.rpm
python-perf-debuginfo-3.10.0-1062.el7.ppc64le.rpm
x86_64:
bpftool-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-1062.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-tools-libs-devel-3.10.0-1062.el7.x86_64.rpm
perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
Red Hat Enterprise Linux Workstation (v. 7):
Source:
kernel-3.10.0-1062.el7.src.rpm
noarch:
kernel-abi-whitelists-3.10.0-1062.el7.noarch.rpm
kernel-doc-3.10.0-1062.el7.noarch.rpm
x86_64:
bpftool-3.10.0-1062.el7.x86_64.rpm
bpftool-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-3.10.0-1062.el7.x86_64.rpm
kernel-debug-3.10.0-1062.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debug-devel-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-1062.el7.x86_64.rpm
kernel-devel-3.10.0-1062.el7.x86_64.rpm
kernel-headers-3.10.0-1062.el7.x86_64.rpm
kernel-tools-3.10.0-1062.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-tools-libs-3.10.0-1062.el7.x86_64.rpm
perf-3.10.0-1062.el7.x86_64.rpm
perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
python-perf-3.10.0-1062.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
Red Hat Enterprise Linux Workstation Optional (v. 7):
x86_64:
bpftool-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-1062.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-1062.el7.x86_64.rpm
kernel-tools-libs-devel-3.10.0-1062.el7.x86_64.rpm
perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-1062.el7.x86_64.rpm
These packages are GPG signed by Red Hat for security. Our key and
details on how to verify the signature are available from
https://access.redhat.com/security/team/key/
Topic
An update for kernel is now available for Red Hat Enterprise Linux 7.Red Hat Product Security has rated this update as having a security impactof Important. A Common Vulnerability Scoring System (CVSS) base score,which gives a detailed severity rating, is available for each vulnerabilityfrom the CVE link(s) in the References section.
Topic
Relevant Releases Architectures
Red Hat Enterprise Linux Client (v. 7) - noarch, x86_64
Red Hat Enterprise Linux Client Optional (v. 7) - x86_64
Red Hat Enterprise Linux ComputeNode (v. 7) - noarch, x86_64
Red Hat Enterprise Linux ComputeNode Optional (v. 7) - x86_64
Red Hat Enterprise Linux Server (v. 7) - noarch, ppc64, ppc64le, s390x, x86_64
Red Hat Enterprise Linux Server Optional (v. 7) - ppc64, ppc64le, x86_64
Red Hat Enterprise Linux Workstation (v. 7) - noarch, x86_64
Red Hat Enterprise Linux Workstation Optional (v. 7) - x86_64
Bugs Fixed
1335986 - BUG: memory allocation failure in inode_doinit_with_dentry()/context_to_sid()
1436351 - [nohz]: wrong user and system time accounting
1537033 - [RHEL7.6] BUG_ON(s->uptodate < disks - 1) condition encountered in RAID6 array with 6 disks and while one disk had failed.
1552203 - RHEL7.4 NFS4.1 client and server repeated SEQUENCE / TEST_STATEIDs with SEQUENCE Reply has SEQ4_STATUS_RECALLABLE_STATE_REVOKED set - NFS server should return NFS4ERR_DELEG_REVOKED or NFS4ERR_BAD_STATEID for revoked delegations
1553216 - CVE-2018-7755 kernel: Information exposure in fd_locked_ioctl function in drivers/block/floppy.c
1555145 - CVE-2018-8087 kernel: Memory leak in drivers/net/wireless/mac80211_hwsim.c:hwsim_new_radio_nl() can lead to potential denial of service
1577640 - getdents on cifs with 4k buffer loses files
1589890 - CVE-2018-10853 kernel: kvm: guest userspace to guest kernel write
1590228 - kernel: openat with O_TMPFILE and mode 0 fails with EACCES (if not root)
1593417 - [mm] kernel BUG at lib/idr.c:1157, kmemcg_id is -1 when creating or destroying mem cgroups
1597747 - CVE-2018-13053 kernel: Integer overflow in the alarm_timer_nsleep function
1597766 - CVE-2018-13093 kernel: NULL pointer dereference in lookup_slow function
1597771 - CVE-2018-13094 kernel: NULL pointer dereference in xfs_da_shrink_inode function
1597775 - CVE-2018-13095 kernel: NULL pointer dereference in fs/xfs/libxfs/xfs_inode_buf.c
1608955 - EFI stub: ERROR: Failed to alloc highmem for initrd
1609699 - virtio-vsock - guest kernel panic with ctrl+c after hot-unplug
1611005 - CVE-2018-14734 kernel: use-after-free in ucma_leave_multicast in drivers/infiniband/core/ucma.c
1613056 - BUG: SELinux does not skip mmap/PROT_EXEC checks for internal files when invoking shmat(2)
1616109 - 7.6 Alpha - Lenovo P52 gnome-shell, suspend reboots machine
1616425 - 7.6 Alpha - Lenovo P52 - Screen goes blank and stays blank(dies)
1619846 - CVE-2018-14625 kernel: use-after-free Read in vhost_transport_send_pkt
1620555 - CVE-2018-15594 kernel: Mishandling of indirect calls weakens Spectre mitigation for paravirtual guests
1622167 - Fix potential divide-by-zero in sunrpc reserved port range calculation
1623067 - CVE-2018-9363 kernel: Buffer overflow in hidp_process_report
1627563 - [RHEL 7.7] raid10 kernel NULL pointer dereference in md_do_sync during raid creation
1627731 - CVE-2018-16658 kernel: Information leak in cdrom_ioctl_drive_status
1628378 - dm-cache does not pass discard I/Os to origin storage device
1631036 - CVE-2018-9516 kernel: HID: debug: Buffer overflow in hid_debug_events_read() in drivers/hid/hid-debug.c
1631045 - CVE-2018-9517 kernel: l2tp: Race condition between pppol2tp_session_create() and l2tp_eth_create()
1645121 - CVE-2018-18281 kernel: TLB flush happens too late on mremap
1659146 - Allow drivers to set .force_blk_mq in scsi_host_template to enable per-driver SCSI-MQ usage
1661503 - CVE-2018-16885 kernel: out-of-bound read in memcpy_fromiovecend()
1663176 - CVE-2019-3459 kernel: Heap address information leak while using L2CAP_GET_CONF_OPT
1663179 - CVE-2019-3460 kernel: Heap address information leak while using L2CAP_PARSE_CONF_RSP
1664110 - CVE-2019-5489 Kernel: page cache side channel attacks
1665990 - df reports negative IUsed value for prjquota set directories.
1671930 - CVE-2019-7222 Kernel: KVM: leak of uninitialized stack contents to guest
1684780 - aio O_DIRECT writes to non-page-aligned file locations on ext4 can result in the overlapped portion of the page containing zeros
1689426 - CVE-2019-3882 kernel: denial of service vector through vfio DMA mappings
1693457 - overlayfs update to upstream 4.18
1698757 - CVE-2019-3900 Kernel: vhost_net: infinite loop while receiving packets leads to DoS
1705937 - CVE-2019-11599 kernel: fix race condition between mmget_not_zero()/get_task_mm() and core dumping
1709164 - CVE-2019-11810 kernel: a NULL pointer dereference in drivers/scsi/megaraid/megaraid_sas_base.c leading to DoS
1712072 - CVE-2019-11833 kernel: fs/ext4/extents.c leads to information disclosure