CVE-2020-9391 - kernel: brk discards top byte of addresses on aarch64 causing heap corruption in glibc malloc

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MEDIUM

kernel: brk discards top byte of addresses on aarch64 causing heap corruption in glibc malloc

Published Feb 25, 2020

5.5

MEDIUM

CVSS 3.1

EPSS 0.52%

Description

An issue was discovered in the Linux kernel 5.4 and 5.5 through 5.5.6 on the AArch64 architecture. It ignores the top byte in the address passed to the brk system call, potentially moving the memory break downwards when the application expects it to move upwards, aka CID-dcde237319e6. This has been observed to cause heap corruption with the GNU C Library malloc implementation.

Affected products

Red Hat Enterprise Linux 5

kernel

Not affected
Red Hat Enterprise Linux 6

kernel

Not affected
Red Hat Enterprise Linux 7

kernel

Not affected
Red Hat Enterprise Linux 7

kernel-alt

Not affected
Red Hat Enterprise Linux 7

kernel-rt

Not affected
Red Hat Enterprise Linux 8

kernel

Not affected
Red Hat Enterprise Linux 8

kernel-rt

Not affected
Red Hat Enterprise MRG 2

kernel-rt

Not affected

Product	Package	State	Advisory
Red Hat Enterprise Linux 5	kernel	Not affected	n/a
Red Hat Enterprise Linux 6	kernel	Not affected	n/a
Red Hat Enterprise Linux 7	kernel	Not affected	n/a
Red Hat Enterprise Linux 7	kernel-alt	Not affected	n/a
Red Hat Enterprise Linux 7	kernel-rt	Not affected	n/a
Red Hat Enterprise Linux 8	kernel	Not affected	n/a
Red Hat Enterprise Linux 8	kernel-rt	Not affected	n/a
Red Hat Enterprise MRG 2	kernel-rt	Not affected	n/a

Remediation

Red Hat statement

The affected code was not introduced into any kernel versions shipped with Red Hat Enterprise Linux making this vulnerable not applicable to these platforms.

Red Hat mitigation

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Weaknesses (2)

CWE-119

Buffer Overflow

CWE-787

Out-of-bounds Write

References (10)

http://www.openwall.com/lists/oss-security/2020/02/25/6
mailing-listx_refsource_MLISTExploitMailing ListThird Party Advisory
https://access.redhat.com/security/cve/CVE-2020-9391
Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1797052
x_refsource_MISCExploitIssue TrackingPatchThird Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1814237
Issue Tracking
https://euvd.enisa.europa.eu/vulnerability/EUVD-2020-30212
Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dcde237319e626d1ec3c9d8b7613032f0fd4663a
x_refsource_MISCMailing ListPatchVendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/O4LH35HOPBJIKYHYFXMBBM75DN75PZHZ/
vendor-advisoryx_refsource_FEDORA
https://nvd.nist.gov/vuln/detail/CVE-2020-9391
https://security.netapp.com/advisory/ntap-20200313-0003/
x_refsource_CONFIRMThird Party Advisory
https://www.cve.org/CVERecord?id=CVE-2020-9391

Link	Providers	Tags
http://www.openwall.com/lists/oss-security/2020/02/25/6		mailing-listx_refsource_MLISTExploitMailing ListThird Party Advisory
https://access.redhat.com/security/cve/CVE-2020-9391		Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1797052		x_refsource_MISCExploitIssue TrackingPatchThird Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1814237		Issue Tracking
https://euvd.enisa.europa.eu/vulnerability/EUVD-2020-30212		Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dcde237319e626d1ec3c9d8b7613032f0fd4663a		x_refsource_MISCMailing ListPatchVendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/O4LH35HOPBJIKYHYFXMBBM75DN75PZHZ/		vendor-advisoryx_refsource_FEDORA
https://nvd.nist.gov/vuln/detail/CVE-2020-9391
https://security.netapp.com/advisory/ntap-20200313-0003/		x_refsource_CONFIRMThird Party Advisory
https://www.cve.org/CVERecord?id=CVE-2020-9391