Ubuntu
linux package

squashfs hardening

  1. Bionic (18.04)
  2. Bug #1816756
Bug #1816756 reported by Tyler Hicks
8
This bug affects 1 person
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Fix Released
Medium
Paolo Pisati
Xenial
Fix Released
Medium
Paolo Pisati
Bionic
Fix Released
Medium
Paolo Pisati

Bug Description

[Impact]

There are a number of recent squashfs hardening fixes in the upstream kernel. They don't have CVE number assigned but it would be good to backport the fixes to harden our kernel against malicious squashfs images. They would harden Ubuntu kernels against potentially malicious snaps.

The changes are:

* https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=01cfb7937a9af2abb1136c7e89fbf3fd92952956
* https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/id=d512584780d3e6a7cacb2f482834849453d444a1
* https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cdbb65c4c7ead680ebe54f4f0d486e2847a500ea
* https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=71755ee5350b63fb1f283de8561cdb61b47f4d1d
* https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a3f94cb99a854fa381fe7fadd97c4f61633717a5

[Test Case]

Unfortunately, we don't have access to the reproducers and I'm unaware of any regression tests for the squashfs kernel driver. It is very important that we don't regress snap usage in Ubuntu. In previous squashfs/snap testing, we've noticed that large snaps, such as chromium and libreoffice, do a good job of exercising the squashfs code. It should be sufficient if we make sure those snaps continue to install and work correctly.

$ sudo snap install chromium
$ sudo snap install libreoffice
$ chromium
< ensure you can browse to various websites >
$ libreoffice
< ensure you can create, save, open documents >

[ Regression Potential ]

Fairly low. The patches are intended to catch corrupted and/or malicious squashfs images. They should not affect well formed squashfs images. These patches are already present in the Cosmic (and Disco) kernel with no known bug reports despite a considerable number of Cosmic users exercising these changes via snaps.

Revision history for this message
Tyler Hicks (tyhicks) wrote :

Bionic: https://lists.ubuntu.com/archives/kernel-team/2019-February/098532.html
Xenial: https://lists.ubuntu.com/archives/kernel-team/2019-February/098538.html

Changed in linux (Ubuntu Xenial):
importance: Undecided → Medium
Changed in linux (Ubuntu Bionic):
importance: Undecided → Medium
Changed in linux (Ubuntu Xenial):
assignee: nobody → Paolo Pisati (p-pisati)
Changed in linux (Ubuntu Bionic):
assignee: nobody → Paolo Pisati (p-pisati)
Changed in linux (Ubuntu Xenial):
status: New → In Progress
Changed in linux (Ubuntu Bionic):
status: New → In Progress
Changed in linux (Ubuntu):
status: In Progress → Fix Released
Khaled El Mously (kmously)
Changed in linux (Ubuntu Xenial):
status: In Progress → Fix Committed
Changed in linux (Ubuntu Bionic):
status: In Progress → Fix Committed
status: Fix Committed → In Progress
Khaled El Mously (kmously)
Changed in linux (Ubuntu Bionic):
status: In Progress → Fix Committed
Revision history for this message
Brad Figg (brad-figg) wrote :

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-xenial' to 'verification-done-xenial'. If the problem still exists, change the tag 'verification-needed-xenial' to 'verification-failed-xenial'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

tags: added: verification-needed-xenial
Revision history for this message
Brad Figg (brad-figg) wrote :

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-bionic' to 'verification-done-bionic'. If the problem still exists, change the tag 'verification-needed-bionic' to 'verification-failed-bionic'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

tags: added: verification-needed-bionic
Revision history for this message
Tyler Hicks (tyhicks) wrote :

The libreoffice and chromium snaps continued to work just fine after upgrading to the xenial and bionic -proposed kernels that contain the squashfs hardening patches. Verification is complete.

tags: added: verification-done-bionic verification-done-xenial
removed: verification-needed-bionic verification-needed-xenial
Revision history for this message
Launchpad Janitor (janitor) wrote :
Download full text (26.1 KiB)

This bug was fixed in the package linux - 4.4.0-145.171

---------------
linux (4.4.0-145.171) xenial; urgency=medium

  * linux: 4.4.0-145.171 -proposed tracker (LP: #1821724)

  * linux-generic should depend on linux-base >=4.1 (LP: #1820419)
    - [Packaging] Fix linux-base dependency

linux (4.4.0-144.170) xenial; urgency=medium

  * linux: 4.4.0-144.170 -proposed tracker (LP: #1819660)

  * Packaging resync (LP: #1786013)
    - [Packaging] resync getabis
    - [Packaging] update helper scripts
    - [Packaging] resync retpoline extraction

  * C++ demangling support missing from perf (LP: #1396654)
    - [Packaging] fix a mistype

  * CVE-2019-9213
    - mm: enforce min addr even if capable() in expand_downwards()

  * CVE-2019-3460
    - Bluetooth: Check L2CAP option sizes returned from l2cap_get_conf_opt

  * Xenial update: 4.4.176 upstream stable release (LP: #1818815)
    - net: fix IPv6 prefix route residue
    - vsock: cope with memory allocation failure at socket creation time
    - hwmon: (lm80) Fix missing unlock on error in set_fan_div()
    - net: Fix for_each_netdev_feature on Big endian
    - net: Add header for usage of fls64()
    - tcp: tcp_v4_err() should be more careful
    - net: Do not allocate page fragments that are not skb aligned
    - tcp: clear icsk_backoff in tcp_write_queue_purge()
    - vxlan: test dev->flags & IFF_UP before calling netif_rx()
    - net: stmmac: Fix a race in EEE enable callback
    - net: ipv4: use a dedicated counter for icmp_v4 redirect packets
    - x86: livepatch: Treat R_X86_64_PLT32 as R_X86_64_PC32
    - mfd: as3722: Handle interrupts on suspend
    - mfd: as3722: Mark PM functions as __maybe_unused
    - net/x25: do not hold the cpu too long in x25_new_lci()
    - mISDN: fix a race in dev_expire_timer()
    - ax25: fix possible use-after-free
    - Linux 4.4.176

  * sky2 ethernet card don't work after returning from suspension
    (LP: #1798921) // Xenial update: 4.4.176 upstream stable release
    (LP: #1818815)
    - sky2: Increase D3 delay again

  * Xenial update: 4.4.175 upstream stable release (LP: #1818813)
    - drm/bufs: Fix Spectre v1 vulnerability
    - staging: iio: adc: ad7280a: handle error from __ad7280_read32()
    - ASoC: Intel: mrfld: fix uninitialized variable access
    - scsi: lpfc: Correct LCB RJT handling
    - ARM: 8808/1: kexec:offline panic_smp_self_stop CPU
    - dlm: Don't swamp the CPU with callbacks queued during recovery
    - x86/PCI: Fix Broadcom CNB20LE unintended sign extension (redux)
    - powerpc/pseries: add of_node_put() in dlpar_detach_node()
    - serial: fsl_lpuart: clear parity enable bit when disable parity
    - ptp: check gettime64 return code in PTP_SYS_OFFSET ioctl
    - staging:iio:ad2s90: Make probe handle spi_setup failure
    - staging: iio: ad7780: update voltage on read
    - ARM: OMAP2+: hwmod: Fix some section annotations
    - modpost: validate symbol names also in find_elf_symbol
    - perf tools: Add Hygon Dhyana support
    - soc/tegra: Don't leak device tree node reference
    - f2fs: move dir data flush to write checkpoint process
    - f2fs: fix wrong return value of f2fs_acl_create
    - sunvdc: Do not spin in an infin...

Changed in linux (Ubuntu Xenial):
status: Fix Committed → Fix Released
Revision history for this message
Launchpad Janitor (janitor) wrote :
Download full text (25.4 KiB)

This bug was fixed in the package linux - 4.15.0-47.50

---------------
linux (4.15.0-47.50) bionic; urgency=medium

  * linux: 4.15.0-47.50 -proposed tracker (LP: #1819716)

  * Packaging resync (LP: #1786013)
    - [Packaging] resync getabis
    - [Packaging] update helper scripts
    - [Packaging] resync retpoline extraction

  * C++ demangling support missing from perf (LP: #1396654)
    - [Packaging] fix a mistype

  * arm-smmu-v3 arm-smmu-v3.3.auto: CMD_SYNC timeout (LP: #1818162)
    - iommu/arm-smmu-v3: Fix unexpected CMD_SYNC timeout

  * Crash in nvme_irq_check() when using threaded interrupts (LP: #1818747)
    - nvme-pci: fix out of bounds access in nvme_cqe_pending

  * CVE-2019-9213
    - mm: enforce min addr even if capable() in expand_downwards()

  * CVE-2019-3460
    - Bluetooth: Check L2CAP option sizes returned from l2cap_get_conf_opt

  * amdgpu with mst WARNING on blanking (LP: #1814308)
    - drm/amd/display: Don't use dc_link in link_encoder
    - drm/amd/display: Move wait for hpd ready out from edp power control.
    - drm/amd/display: eDP sequence BL off first then DP blank.
    - drm/amd/display: Fix unused variable compilation error
    - drm/amd/display: Fix warning about misaligned code
    - drm/amd/display: Fix MST dp_blank REG_WAIT timeout

  * tun/tap: unable to manage carrier state from userland (LP: #1806392)
    - tun: implement carrier change

  * CVE-2019-8980
    - exec: Fix mem leak in kernel_read_file

  * raw_skew in timer from the ubuntu_kernel_selftests failed on Bionic
    (LP: #1811194)
    - selftest: timers: Tweak raw_skew to SKIP when ADJ_OFFSET/other clock
      adjustments are in progress

  * [Packaging] Allow overlay of config annotations (LP: #1752072)
    - [Packaging] config-check: Add an include directive

  * CVE-2019-7308
    - bpf: move {prev_,}insn_idx into verifier env
    - bpf: move tmp variable into ax register in interpreter
    - bpf: enable access to ax register also from verifier rewrite
    - bpf: restrict map value pointer arithmetic for unprivileged
    - bpf: restrict stack pointer arithmetic for unprivileged
    - bpf: restrict unknown scalars of mixed signed bounds for unprivileged
    - bpf: fix check_map_access smin_value test when pointer contains offset
    - bpf: prevent out of bounds speculation on pointer arithmetic
    - bpf: fix sanitation of alu op with pointer / scalar type from different
      paths
    - bpf: add various test cases to selftests

  * CVE-2017-5753
    - bpf: properly enforce index mask to prevent out-of-bounds speculation
    - bpf: fix inner map masking to prevent oob under speculation

  * BPF: kernel pointer leak to unprivileged userspace (LP: #1815259)
    - bpf/verifier: disallow pointer subtraction

  * squashfs hardening (LP: #1816756)
    - squashfs: more metadata hardening
    - squashfs metadata 2: electric boogaloo
    - squashfs: more metadata hardening
    - Squashfs: Compute expected length from inode size rather than block length

  * efi/arm/arm64: Allow SetVirtualAddressMap() to be omitted (LP: #1814982)
    - efi/arm/arm64: Allow SetVirtualAddressMap() to be omitted

  * Update ENA driver to version 2.0.3K (LP: #1816806)...

Changed in linux (Ubuntu Bionic):
status: Fix Committed → Fix Released
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