| Name | CVE-2021-3929 |
| Description | A DMA reentrancy issue was found in the NVM Express Controller (NVME) emulation in QEMU. This CVE is similar to CVE-2021-3750 and, just like it, when the reentrancy write triggers the reset function nvme_ctrl_reset(), data structs will be freed leading to a use-after-free issue. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition or, potentially, executing arbitrary code within the context of the QEMU process on the host. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| qemu (PTS) | buster | 1:3.1+dfsg-8+deb10u8 | fixed |
| buster (security) | 1:3.1+dfsg-8+deb10u10 | fixed | |
| bullseye (security), bullseye | 1:5.2+dfsg-11+deb11u2 | vulnerable | |
| bookworm | 1:7.2+dfsg-7+deb12u1 | fixed | |
| trixie | 1:8.0.4+dfsg-3 | fixed | |
| sid | 1:8.1.0+ds-6 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| qemu | source | stretch | (not affected) | |||
| qemu | source | buster | (not affected) | |||
| qemu | source | (unstable) | 1:7.0+dfsg-1 |
[bullseye] - qemu <ignored> (Minor issue; nvme support preliminary supported)
[buster] - qemu <not-affected> (nvme support preliminary supported; PoC doesn't trigger)
[stretch] - qemu <not-affected> (Vulnerable code introduced later)
https://bugzilla.redhat.com/show_bug.cgi?id=2020298
https://gitlab.com/qemu-project/qemu/-/issues/556 (generic)
https://gitlab.com/qemu-project/qemu/-/issues/782 (specific)
Proposed patchset (generic): https://lists.nongnu.org/archive/html/qemu-devel/2021-08/msg03692.html
Proposed patchset (specific): https://lists.nongnu.org/archive/html/qemu-devel/2022-01/msg04577.html
Fixed by: https://gitlab.com/qemu-project/qemu/-/commit/736b01642d85be832385063f278fe7cd4ffb5221 (v7.0.0-rc0)