Description
An issue was discovered in ide_dma_cb() in hw/ide/core.c in QEMU 2.4.0 through 4.2.0. The guest system can crash the QEMU process in the host system via a special SCSI_IOCTL_SEND_COMMAND. It hits an assertion that implies that the size of successful DMA transfers there must be a multiple of 512 (the size of a sector). NOTE: a member of the QEMU security team disputes the significance of this issue because a "privileged guest user has many ways to cause similar DoS effect, without triggering this assert.
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 | 1:5.0-1 | — |
| Debian 13 | qemu | 1:5.0-1 | — |
| Debian 12 | qemu | 1:5.0-1 | — |
References
- https://lists.nongnu.org/archive/html/qemu-devel/2019-07/msg01651.html
- https://lists.nongnu.org/archive/html/qemu-devel/2019-11/msg00597.html
- https://lists.nongnu.org/archive/html/qemu-devel/2019-11/msg02165.html
- https://www.mail-archive.com/qemu-devel%40nongnu.org/msg667396.html
- https://lists.nongnu.org/archive/html/qemu-devel/2019-07/msg03869.html