132 lines
5 KiB
Text
132 lines
5 KiB
Text
-----BEGIN PGP SIGNED MESSAGE-----
|
|
Hash: SHA512
|
|
|
|
=============================================================================
|
|
FreeBSD-SA-19:13.pts Security Advisory
|
|
The FreeBSD Project
|
|
|
|
Topic: pts(4) write-after-free
|
|
|
|
Category: core
|
|
Module: kernel
|
|
Announced: 2019-07-24
|
|
Credits: syzkaller
|
|
Affects: All supported versions of FreeBSD.
|
|
Corrected: 2019-07-07 14:19:46 UTC (stable/12, 12.0-STABLE)
|
|
2019-07-24 12:53:06 UTC (releng/12.0, 12.0-RELEASE-p8)
|
|
2019-07-07 14:20:14 UTC (stable/11, 11.2-STABLE)
|
|
2019-07-24 12:53:06 UTC (releng/11.2, 11.2-RELEASE-p12)
|
|
2019-07-24 12:53:06 UTC (releng/11.3, 11.3-RELEASE-p1)
|
|
CVE Name: CVE-2019-5606
|
|
|
|
For general information regarding FreeBSD Security Advisories,
|
|
including descriptions of the fields above, security branches, and the
|
|
following sections, please visit <URL:https://security.FreeBSD.org/>.
|
|
|
|
I. Background
|
|
|
|
The posix_openpt(2) system call allocates a pseudo-terminal device and
|
|
returns a descriptor referencing that device. Such a descriptor may be
|
|
configured such that a SIGIO signal will be sent to a designated process
|
|
or process group when the device is ready to perform I/O.
|
|
|
|
II. Problem Description
|
|
|
|
The code which handles a close(2) of a descriptor created by
|
|
posix_openpt(2) fails to undo the configuration which causes SIGIO to be
|
|
raised. This bug can lead to a write-after-free of kernel memory.
|
|
|
|
III. Impact
|
|
|
|
The bug permits malicious code to trigger a write-after-free, which may
|
|
be used to gain root privileges or escape a jail.
|
|
|
|
IV. Workaround
|
|
|
|
No workaround is available.
|
|
|
|
V. Solution
|
|
|
|
Upgrade your vulnerable system to a supported FreeBSD stable or
|
|
release / security branch (releng) dated after the correction date.
|
|
|
|
Perform one of the following:
|
|
|
|
1) To update your vulnerable system via a binary patch:
|
|
|
|
Systems running a RELEASE version of FreeBSD on the i386 or amd64
|
|
platforms can be updated via the freebsd-update(8) utility:
|
|
|
|
# freebsd-update fetch
|
|
# freebsd-update install
|
|
# shutdown -r +10min "Security update"
|
|
|
|
2) To update your vulnerable system via a source code patch:
|
|
|
|
The following patches have been verified to apply to the applicable
|
|
FreeBSD release branches.
|
|
|
|
a) Download the relevant patch from the location below, and verify the
|
|
detached PGP signature using your PGP utility.
|
|
|
|
# fetch https://security.FreeBSD.org/patches/SA-19:13/pts.patch
|
|
# fetch https://security.FreeBSD.org/patches/SA-19:13/pts.patch.asc
|
|
# gpg --verify pts.patch.asc
|
|
|
|
b) Apply the patch. Execute the following commands as root:
|
|
|
|
# cd /usr/src
|
|
# patch < /path/to/patch
|
|
|
|
c) Recompile your kernel as described in
|
|
<URL:https://www.FreeBSD.org/handbook/kernelconfig.html> and reboot the
|
|
system.
|
|
|
|
VI. Correction details
|
|
|
|
The following list contains the correction revision numbers for each
|
|
affected branch.
|
|
|
|
Branch/path Revision
|
|
- -------------------------------------------------------------------------
|
|
stable/12/ r349805
|
|
releng/12.0/ r350282
|
|
stable/11/ r349806
|
|
releng/11.2/ r350282
|
|
releng/11.3/ r350282
|
|
- -------------------------------------------------------------------------
|
|
|
|
To see which files were modified by a particular revision, run the
|
|
following command, replacing NNNNNN with the revision number, on a
|
|
machine with Subversion installed:
|
|
|
|
# svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base
|
|
|
|
Or visit the following URL, replacing NNNNNN with the revision number:
|
|
|
|
<URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN>
|
|
|
|
VII. References
|
|
|
|
<URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-5606>
|
|
|
|
The latest revision of this advisory is available at
|
|
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-19:13.pts.asc>
|
|
-----BEGIN PGP SIGNATURE-----
|
|
|
|
iQKTBAEBCgB9FiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAl04Wl9fFIAAAAAALgAo
|
|
aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD
|
|
MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n
|
|
5cLZDA//SGC+7Vghtofm/CzylIXhC1drFOxNYJOF7KEJqDwsRR3U9S99Q9NBWS5+
|
|
e+/vJzvV0+epZNQXDlit5a76jGwy4fNuutNh0J3APHe/l0Zp/PhM56IwRWQgqAkQ
|
|
hF67xhHxFZs8AH6/bw21N4IkRrAZHmrrCY8ubZArjoUi0gCoFzAYRw1Nh/JTQoLS
|
|
IGuqUFaMZWKvu3aeJiikLjHiJUMRAY7sxh+iSBSp99dsLkASqQZtx1grmosljttN
|
|
fuD7qO2f067EWUpC50JTbNt9V7za854hrlOp8jn1g51O4fWWJoEEL2/0VUeOO+fr
|
|
aGS9UNal25NPr2zGzx2t0u1VNE3/YKoZ0tq+mQYtaXke32ZO15Ufby0YcLU4DF8d
|
|
dU1ZoG2AGbWmBqgQ982hocq5Dn0r5yCHXDeEGguE1DsfyBuUEZw6zfYRtzIQ0swk
|
|
wDrdETxpIMa8jaSGtDw2bilrLNRIVqYkXBJftC3fpXhlz6PyU6bZaFm00xrs7z1D
|
|
EJMkuIWho9oMqLTU7bZNHv7JD4G3ziTF1h2tGXGcEKp02ImNZQnw3w5PBberFgto
|
|
H4uJQCWgFqqddkjnSidX3Uj676LC99ERDEUlqi+xnXMmBScJnQuRtiUdbpOCkPD2
|
|
gLJmcyy7qjKw87i8KaQF5hUcym2D9xygbUV+I4RT93jR2DCVBA0=
|
|
=Cpu+
|
|
-----END PGP SIGNATURE-----
|