DEBIAN-CVE-2021-47555
- Source
- https://security-tracker.debian.org/tracker/CVE-2021-47555
- Import Source
- https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47555.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/DEBIAN-CVE-2021-47555
- Upstream
- Published
- 2024-05-24T15:15:20Z
- Modified
- 2025-09-25T23:27:11.156298Z
- Severity
-
- 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- [none]
- Details
-
In the Linux kernel, the following vulnerability has been resolved: net: vlan: fix underflow for the realdev refcnt Inject error before devhold(realdev) in registervlandev(), and execute the following testcase: ip link add dev dummy1 type dummy ip link add name dummy1.100 link dummy1 type vlan id 100 ip link del dev dummy1 When the dummy netdevice is removed, we will get a WARNING as following: ======================================================================= refcountt: decrement hit 0; leaking memory. WARNING: CPU: 2 PID: 0 at lib/refcount.c:31 refcountwarnsaturate+0xbf/0x1e0 and an endless loop of: ======================================================================= unregisternetdevice: waiting for dummy1 to become free. Usage count = -1073741824 That is because devput(realdev) in vlandevfree() be called without devhold(realdev) in registervlandev(). It makes the refcnt of realdev underflow. Move the devhold(realdev) to vlandevinit() which is the call-back of ndoinit(). That makes devhold() and devput() for vlan's realdev symmetrical.
- References
Affected packages
Debian:11 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source
Debian:12 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source
Debian:13 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source
Debian:14 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source