CVE-2016-4557

Published: 5 May 2016

The replace_map_fd_with_map_ptr function in kernel/bpf/verifier.c in the Linux kernel before 4.5.5 does not properly maintain an fd data structure, which allows local users to gain privileges or cause a denial of service (use-after-free) via crafted BPF instructions that reference an incorrect file descriptor.

From the Ubuntu Security Team

Jann Horn discovered that the extended Berkeley Packet Filter (eBPF) implementation in the Linux kernel did not properly reference count file descriptors, leading to a use-after-free. A local unprivileged attacker could use this to gain administrative privileges.

Notes

Author	Note
jdstrand	android kernels (flo, goldfish, grouper, maguro, mako and manta) are not supported on the Ubuntu Touch 14.10 and earlier preview kernels linux-lts-saucy no longer receives official support linux-lts-quantal no longer receives official support
sbeattie	affects 4.4 kernels only introduced in 0246e64d9a5f, but made exploitable by 1be7f75d1668

Author

Note

jdstrand

android kernels (flo, goldfish, grouper, maguro, mako and manta) are
not supported on the Ubuntu Touch 14.10 and earlier preview kernels
linux-lts-saucy no longer receives official support
linux-lts-quantal no longer receives official support

sbeattie

affects 4.4 kernels only
introduced in 0246e64d9a5f, but made exploitable by 1be7f75d1668

Priority

Cvss 3 Severity Score

7.8

Score breakdown

Status

Package	Release	Status
linux-aws Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Not vulnerable (4.4.0-1002.2)
	xenial	Not vulnerable (4.4.0-1001.10)
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-flo Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	wily	Not vulnerable
	xenial	Not vulnerable
	yakkety	Not vulnerable
	upstream	Released (4.6~rc6)
linux-gke Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	xenial	Not vulnerable (4.4.0-1003.3)
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-goldfish Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	wily	Not vulnerable
	xenial	Not vulnerable
	yakkety	Not vulnerable
	upstream	Released (4.6~rc6)
linux-grouper Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-hwe Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	xenial	Not vulnerable (4.8.0-36.36~16.04.1)
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-hwe-edge Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	xenial	Not vulnerable (4.8.0-36.36~16.04.1)
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-linaro-vexpress Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-lts-quantal Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
	This package is not directly supported by the Ubuntu Security Team
linux-lts-raring Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-lts-saucy Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
	This package is not directly supported by the Ubuntu Security Team
linux-lts-trusty Launchpad, Ubuntu, Debian	precise	Not vulnerable
	trusty	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-lts-utopic Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was not-affected)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-lts-vivid Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was not-affected)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-lts-wily Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was not-affected)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-lts-xenial Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Released (4.4.0-22.39~14.04.1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-maguro Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-mako Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	wily	Not vulnerable
	xenial	Not vulnerable
	yakkety	Not vulnerable
	upstream	Released (4.6~rc6)
linux-manta Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	wily	Not vulnerable
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-qcm-msm Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux-raspi2 Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	wily	Not vulnerable
	xenial	Released (4.4.0-1010.12)
	yakkety	Not vulnerable (4.4.0-1010.12)
	upstream	Released (4.6~rc6)
linux-snapdragon Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	wily	Does not exist
	xenial	Released (4.4.0-1013.14)
	yakkety	Not vulnerable (4.4.0-1013.14)
	upstream	Released (4.6~rc6)
linux-ti-omap4 Launchpad, Ubuntu, Debian	precise	Not vulnerable
	trusty	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	upstream	Released (4.6~rc6)
linux Launchpad, Ubuntu, Debian	upstream	Released (4.6~rc6)
	precise	Not vulnerable
	trusty	Not vulnerable
	wily	Not vulnerable
	xenial	Released (4.4.0-22.39)
	yakkety	Not vulnerable (4.4.0-22.39)
	Patches: Introduced by 1be7f75d1668d6296b80bf35dcf6762393530afc Fixed by 8358b02bf67d3a5d8a825070e1aa73f25fb2e4c7
linux-armadaxp Launchpad, Ubuntu, Debian	upstream	Released (4.6~rc6)
	precise	Not vulnerable
	trusty	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	This package is not directly supported by the Ubuntu Security Team
linux-linaro-omap Launchpad, Ubuntu, Debian	upstream	Released (4.6~rc6)
	precise	Ignored (end of life)
	trusty	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-linaro-shared Launchpad, Ubuntu, Debian	upstream	Released (4.6~rc6)
	precise	Ignored (end of life)
	trusty	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist

Severity score breakdown

Parameter	Value
Base score	7.8
Attack vector	Local
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Bugs

https://launchpad.net/bugs/1578705

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