Description
The mcf_fec_do_tx function in hw/net/mcf_fec.c in QEMU (aka Quick Emulator) does not properly limit the buffer descriptor count when transmitting packets, which allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via vectors involving a buffer descriptor with a length of 0 and crafted values in bd.flags.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | qemu | 1:2.8+dfsg-1 | — |
| Debian 13 | qemu | 1:2.8+dfsg-1 | — |
| Debian 12 | qemu | 1:2.8+dfsg-1 | — |
| Debian 8 | qemu | 1:2.1+dfsg-12+deb8u8 | DLA-1599-1 |
| Debian 7 | qemu +1 | 1.1.2+dfsg-6+deb7u16 | DLA-653-1, DLA-652-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | qemu | 1:2.5+dfsg-5ubuntu10.6 | USN-3125-1 |
| Ubuntu 14.04 LTS | qemu | 2.0.0+dfsg-2ubuntu1.30 | USN-3125-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | qemu | 2.6.2-31.2 | SUSE-SU-2016:2879-1 |
| SLES 12 SP2 | xen | 4.7.1_02-25.1 | SUSE-SU-2016:3067-1 |
| SLES 12 SP1 | qemu | 2.3.1-24.6 | SUSE-SU-2016:2988-1 |
| SLES 12 SP1 | xen | 4.5.5_02-22.3.1 | SUSE-SU-2016:3083-1 |
| SLES 12 | qemu | 2.0.2-48.25.1 | SUSE-SU-2016:2936-1 |
| SLES 12 | xen | 4.4.4_05-22.25.1 | SUSE-SU-2016:3156-1 |
| SLES 11 SP4 | kvm | 1.4.2-50.1 | SUSE-SU-2016:2902-1 |
| SLES 11 SP4 | xen | 4.4.4_10-43.5 | SUSE-SU-2016:3174-1 |
| SLES 11 SP3 | xen | 4.2.5_21-30.1 | SUSE-SU-2016:3273-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP2 | xen | 4.1.6_08-32.1 | SUSE-SU-2016:3044-1 |
| SLES for SAP 12 SP2 | qemu | 2.6.2-31.2 | SUSE-SU-2016:2879-1 |
| SLES for SAP 12 SP2 | xen | 4.7.1_02-25.1 | SUSE-SU-2016:3067-1 |
| SLES for SAP 12 SP1 | qemu | 2.3.1-24.6 | SUSE-SU-2016:2988-1 |
| SLES for SAP 12 SP1 | xen | 4.5.5_02-22.3.1 | SUSE-SU-2016:3083-1 |
| SLES for SAP 12 | qemu | 2.0.2-48.25.1 | SUSE-SU-2016:2936-1 |
| SLES for SAP 12 | xen | 4.4.4_05-22.25.1 | SUSE-SU-2016:3156-1 |
| SLES for SAP 11 SP4 | kvm | 1.4.2-50.1 | SUSE-SU-2016:2902-1 |
| SLES for SAP 11 SP4 | xen | 4.4.4_10-43.5 | SUSE-SU-2016:3174-1 |
| SUSE OpenStack Cloud 5 | xen | 4.2.5_21-30.1 | SUSE-SU-2016:3273-1 |
| SUSE Manager Proxy 2.1 | xen | 4.2.5_21-30.1 | SUSE-SU-2016:3273-1 |
| SUSE Manager 2.1 | xen | 4.2.5_21-30.1 | SUSE-SU-2016:3273-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | xen | 4.2.5_21-30.1 | SUSE-SU-2016:3273-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | qemu | 6.1.0-32.1 | openSUSE-SU-2024:11287-1 |
| openSUSE Tumbleweed | xen | 4.15.1_01-1.2 | openSUSE-SU-2024:11520-1 |
Advisories 16
- DLA-653-1 qemu-kvm - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-652-1 qemu - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1599-1 qemu - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-3125-1 qemu, qemu-kvm vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2016:3044-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:2936-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:2902-1 Security update for kvm SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:2879-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:3067-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:3174-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:3156-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:3273-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:2988-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11287-1 qemu-6.1.0-32.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- openSUSE-SU-2024:11520-1 xen-4.15.1_01-1.2 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- SUSE-SU-2016:3083-1 Security update for xen SUSE / openSUSE Security Updates · May 2, 2025
References
- [oss-security] 20161003 CVE request Qemu: net: Infinite loop in mcf_fec_do_tx mailing-list
- [qemu-devel] 20160922 [PATCH v2] net: mcf: limit buffer descriptor count mailing-list
- GLSA-201611-11 vendor-advisory
- http://git.qemu.org/?p=qemu.git%3Ba=commit%3Bh=070c4b92b8cd5390889716677a0b92444d6e087a
- openSUSE-SU-2016:3237 vendor-advisory
- 93273 vdb-entry
- [debian-lts-announce] 20181130 [SECURITY] [DLA 1599-1] qemu security update mailing-list
- [oss-security] 20161003 Re: CVE request Qemu: net: Infinite loop in mcf_fec_do_tx mailing-list