CVE-2024-49940
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2024-49940
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-49940.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2024-49940
- Downstream
- Related
- Published
- 2024-10-21T18:01:59Z
- Modified
- 2025-10-17T14:41:18.650157Z
- Summary
- l2tp: prevent possible tunnel refcount underflow
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
l2tp: prevent possible tunnel refcount underflow
When a session is created, it sets a backpointer to its tunnel. When the session refcount drops to 0, l2tpsessionfree drops the tunnel refcount if session->tunnel is non-NULL. However, session->tunnel is set in l2tpsessioncreate, before the tunnel refcount is incremented by l2tpsessionregister, which leaves a small window where session->tunnel is non-NULL when the tunnel refcount hasn't been bumped.
Moving the assignment to l2tpsessionregister is trivial but l2tpsessioncreate calls l2tpsessionsetheaderlen which uses session->tunnel to get the tunnel's encap. Add an encap arg to l2tpsessionsetheaderlen to avoid using session->tunnel.
If l2tpv3 sessions have colliding IDs, it is possible for l2tpv3sessionget to race with l2tpsession_register and fetch a session which doesn't yet have session->tunnel set. Add a check for this case.
- References
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced1da177e4c3f41524e886b7f1b8a0c1fc7321cac2Fixedf7415e60c25a6108cd7955a20b2e66b6251ffe02
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced1da177e4c3f41524e886b7f1b8a0c1fc7321cac2Fixed24256415d18695b46da06c93135f5b51c548b950
Affected versions
v2.*
v2.6.12
v2.6.12-rc2
v2.6.12-rc3
v2.6.12-rc4
v2.6.12-rc5
v2.6.12-rc6
v2.6.13
v2.6.13-rc1
v2.6.13-rc2
v2.6.13-rc3
v2.6.13-rc4
v2.6.13-rc5
v2.6.13-rc6
v2.6.13-rc7
v2.6.14
v2.6.14-rc1
v2.6.14-rc2
v2.6.14-rc3
v2.6.14-rc4
v2.6.14-rc5
v2.6.15
v2.6.15-rc1
v2.6.15-rc2
v2.6.15-rc3
v2.6.15-rc4
v2.6.15-rc5
v2.6.15-rc6
v2.6.15-rc7
v2.6.16
v2.6.16-rc1
v2.6.16-rc2
v2.6.16-rc3
v2.6.16-rc4
v2.6.16-rc5
v2.6.16-rc6
v2.6.17
v2.6.17-rc1
v2.6.17-rc2
v2.6.17-rc3
v2.6.17-rc4
v2.6.17-rc5
v2.6.17-rc6
v2.6.18
v2.6.18-rc1
v2.6.18-rc2
v2.6.18-rc3
v2.6.18-rc4
v2.6.18-rc5
v2.6.18-rc6
v2.6.18-rc7
v2.6.19
v2.6.19-rc1
v2.6.19-rc2
v2.6.19-rc3
v2.6.19-rc4
v2.6.19-rc5
v2.6.19-rc6
v2.6.20
v2.6.20-rc1
v2.6.20-rc2
v2.6.20-rc3
v2.6.20-rc4
v2.6.20-rc5
v2.6.20-rc6
v2.6.20-rc7
v2.6.21
v2.6.21-rc1
v2.6.21-rc2
v2.6.21-rc3
v2.6.21-rc4
v2.6.21-rc5
v2.6.21-rc6
v2.6.21-rc7
v2.6.22
v2.6.22-rc1
v2.6.22-rc2
v2.6.22-rc3
v2.6.22-rc4
v2.6.22-rc5
v2.6.22-rc6
v2.6.22-rc7
v2.6.23
v2.6.23-rc1
v2.6.23-rc2
v2.6.23-rc3
v2.6.23-rc4
v2.6.23-rc5
v2.6.23-rc6
v2.6.23-rc7
v2.6.23-rc8
v2.6.23-rc9
v2.6.24
v2.6.24-rc1
v2.6.24-rc2
v2.6.24-rc3
v2.6.24-rc4
v2.6.24-rc5
v2.6.24-rc6
v2.6.24-rc7
v2.6.24-rc8
v2.6.25
v2.6.25-rc1
v2.6.25-rc2
v2.6.25-rc3
v2.6.25-rc4
v2.6.25-rc5
v2.6.25-rc6
v2.6.25-rc7
v2.6.25-rc8
v2.6.25-rc9
v2.6.26
v2.6.26-rc1
v2.6.26-rc2
v2.6.26-rc3
v2.6.26-rc4
v2.6.26-rc5
v2.6.26-rc6
v2.6.26-rc7
v2.6.26-rc8
v2.6.26-rc9
v2.6.27
v2.6.27-rc1
v2.6.27-rc2
v2.6.27-rc3
v2.6.27-rc4
v2.6.27-rc5
v2.6.27-rc6
v2.6.27-rc7
v2.6.27-rc8
v2.6.27-rc9
v2.6.28
v2.6.28-rc1
v2.6.28-rc2
v2.6.28-rc3
v2.6.28-rc4
v2.6.28-rc5
v2.6.28-rc6
v2.6.28-rc7
v2.6.28-rc8
v2.6.28-rc9
v2.6.29
v2.6.29-rc1
v2.6.29-rc2
v2.6.29-rc3
v2.6.29-rc4
v2.6.29-rc5
v2.6.29-rc6
v2.6.29-rc7
v2.6.29-rc8
v2.6.30
v2.6.30-rc1
v2.6.30-rc2
v2.6.30-rc3
v2.6.30-rc4
v2.6.30-rc5
v2.6.30-rc6
v2.6.30-rc7
v2.6.30-rc8
v2.6.31
v2.6.31-rc1
v2.6.31-rc2
v2.6.31-rc3
v2.6.31-rc4
v2.6.31-rc5
v2.6.31-rc6
v2.6.31-rc7
v2.6.31-rc8
v2.6.31-rc9
v2.6.32
v2.6.32-rc1
v2.6.32-rc2
v2.6.32-rc3
v2.6.32-rc4
v2.6.32-rc5
v2.6.32-rc6
v2.6.32-rc7
v2.6.32-rc8
v2.6.33
v2.6.33-rc1
v2.6.33-rc2
v2.6.33-rc3
v2.6.33-rc4
v2.6.33-rc5
v2.6.33-rc6
v2.6.33-rc7
v2.6.33-rc8
v2.6.34
v2.6.34-rc1
v2.6.34-rc2
v2.6.34-rc3
v2.6.34-rc4
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v2.6.35
v2.6.35-rc1
v2.6.35-rc2
v2.6.35-rc3
v2.6.35-rc4
v2.6.35-rc5
v2.6.35-rc6
v2.6.36
v2.6.36-rc1
v2.6.36-rc2
v2.6.36-rc3
v2.6.36-rc4
v2.6.36-rc5
v2.6.36-rc6
v2.6.36-rc7
v2.6.36-rc8
v2.6.37
v2.6.37-rc1
v2.6.37-rc2
v2.6.37-rc3
v2.6.37-rc4
v2.6.37-rc5
v2.6.37-rc6
v2.6.37-rc7
v2.6.37-rc8
v2.6.38
v2.6.38-rc1
v2.6.38-rc2
v2.6.38-rc3
v2.6.38-rc4
v2.6.38-rc5
v2.6.38-rc6
v2.6.38-rc7
v2.6.38-rc8
v2.6.39
v2.6.39-rc1
v2.6.39-rc2
v2.6.39-rc3
v2.6.39-rc4
v2.6.39-rc5
v2.6.39-rc6
v2.6.39-rc7
v3.*
v3.0
v3.0-rc1
v3.0-rc2
v3.0-rc3
v3.0-rc4
v3.0-rc5
v3.0-rc6
v3.0-rc7
v3.1
v3.1-rc1
v3.1-rc10
v3.1-rc2
v3.1-rc3
v3.1-rc4
v3.1-rc5
v3.1-rc6
v3.1-rc7
v3.1-rc8
v3.1-rc9
v3.10
v3.10-rc1
v3.10-rc2
v3.10-rc3
v3.10-rc4
v3.10-rc5
v3.10-rc6
v3.10-rc7
v3.11
v3.11-rc1
v3.11-rc2
v3.11-rc3
v3.11-rc4
v3.11-rc5
v3.11-rc6
v3.11-rc7
v3.12
v3.12-rc1
v3.12-rc2
v3.12-rc3
v3.12-rc4
v3.12-rc5
v3.12-rc6
v3.12-rc7
v3.13
v3.13-rc1
v3.13-rc2
v3.13-rc3
v3.13-rc4
v3.13-rc5
v3.13-rc6
v3.13-rc7
v3.13-rc8
v3.14
v3.14-rc1
v3.14-rc2
v3.14-rc3
v3.14-rc4
v3.14-rc5
v3.14-rc6
v3.14-rc7
v3.14-rc8
v3.15
v3.15-rc1
v3.15-rc2
v3.15-rc3
v3.15-rc4
v3.15-rc5
v3.15-rc6
v3.15-rc7
v3.15-rc8
v3.16
v3.16-rc1
v3.16-rc2
v3.16-rc3
v3.16-rc4
v3.16-rc5
v3.16-rc6
v3.16-rc7
v3.17
v3.17-rc1
v3.17-rc2
v3.17-rc3
v3.17-rc4
v3.17-rc5
v3.17-rc6
v3.17-rc7
v3.18
v3.18-rc1
v3.18-rc2
v3.18-rc3
v3.18-rc4
v3.18-rc5
v3.18-rc6
v3.18-rc7
v3.19
v3.19-rc1
v3.19-rc2
v3.19-rc3
v3.19-rc4
v3.19-rc5
v3.19-rc6
v3.19-rc7
v3.2
v3.2-rc1
v3.2-rc2
v3.2-rc3
v3.2-rc4
v3.2-rc5
v3.2-rc6
v3.2-rc7
v3.3
v3.3-rc1
v3.3-rc2
v3.3-rc3
v3.3-rc4
v3.3-rc5
v3.3-rc6
v3.3-rc7
v3.4
v3.4-rc1
v3.4-rc2
v3.4-rc3
v3.4-rc4
v3.4-rc5
v3.4-rc6
v3.4-rc7
v3.5
v3.5-rc1
v3.5-rc2
v3.5-rc3
v3.5-rc4
v3.5-rc5
v3.5-rc6
v3.5-rc7
v3.6
v3.6-rc1
v3.6-rc2
v3.6-rc3
v3.6-rc4
v3.6-rc5
v3.6-rc6
v3.6-rc7
v3.7
v3.7-rc1
v3.7-rc2
v3.7-rc3
v3.7-rc4
v3.7-rc5
v3.7-rc6
v3.7-rc7
v3.7-rc8
v3.8
v3.8-rc1
v3.8-rc2
v3.8-rc3
v3.8-rc4
v3.8-rc5
v3.8-rc6
v3.8-rc7
v3.9
v3.9-rc1
v3.9-rc2
v3.9-rc3
v3.9-rc4
v3.9-rc5
v3.9-rc6
v3.9-rc7
v3.9-rc8
v4.*
v4.0
v4.0-rc1
v4.0-rc2
v4.0-rc3
v4.0-rc4
v4.0-rc5
v4.0-rc6
v4.0-rc7
v4.1
v4.1-rc1
v4.1-rc2
v4.1-rc3
v4.1-rc4
v4.1-rc5
v4.1-rc6
v4.1-rc7
v4.1-rc8
v4.10
v4.10-rc1
v4.10-rc2
v4.10-rc3
v4.10-rc4
v4.10-rc5
v4.10-rc6
v4.10-rc7
v4.10-rc8
v4.11
v4.11-rc1
v4.11-rc2
v4.11-rc3
v4.11-rc4
v4.11-rc5
v4.11-rc6
v4.11-rc7
v4.11-rc8
v4.12
v4.12-rc1
v4.12-rc2
v4.12-rc3
v4.12-rc4
v4.12-rc5
v4.12-rc6
v4.12-rc7
v4.13
v4.13-rc1
v4.13-rc2
v4.13-rc3
v4.13-rc4
v4.13-rc5
v4.13-rc6
v4.13-rc7
v4.14
v4.14-rc1
v4.14-rc2
v4.14-rc3
v4.14-rc4
v4.14-rc5
v4.14-rc6
v4.14-rc7
v4.14-rc8
v4.15
v4.15-rc1
v4.15-rc2
v4.15-rc3
v4.15-rc4
v4.15-rc5
v4.15-rc6
v4.15-rc7
v4.15-rc8
v4.15-rc9
v4.16
v4.16-rc1
v4.16-rc2
v4.16-rc3
v4.16-rc4
v4.16-rc5
v4.16-rc6
v4.16-rc7
v4.17
v4.17-rc1
v4.17-rc2
v4.17-rc3
v4.17-rc4
v4.17-rc5
v4.17-rc6
v4.17-rc7
v4.18
v4.18-rc1
v4.18-rc2
v4.18-rc3
v4.18-rc4
v4.18-rc5
v4.18-rc6
v4.18-rc7
v4.18-rc8
v4.19
v4.19-rc1
v4.19-rc2
v4.19-rc3
v4.19-rc4
v4.19-rc5
v4.19-rc6
v4.19-rc7
v4.19-rc8
v4.2
v4.2-rc1
v4.2-rc2
v4.2-rc3
v4.2-rc4
v4.2-rc5
v4.2-rc6
v4.2-rc7
v4.2-rc8
v4.20
v4.20-rc1
v4.20-rc2
v4.20-rc3
v4.20-rc4
v4.20-rc5
v4.20-rc6
v4.20-rc7
v4.3
v4.3-rc1
v4.3-rc2
v4.3-rc3
v4.3-rc4
v4.3-rc5
v4.3-rc6
v4.3-rc7
v4.4
v4.4-rc1
v4.4-rc2
v4.4-rc3
v4.4-rc4
v4.4-rc5
v4.4-rc6
v4.4-rc7
v4.4-rc8
v4.5
v4.5-rc1
v4.5-rc2
v4.5-rc3
v4.5-rc4
v4.5-rc5
v4.5-rc6
v4.5-rc7
v4.6
v4.6-rc1
v4.6-rc2
v4.6-rc3
v4.6-rc4
v4.6-rc5
v4.6-rc6
v4.6-rc7
v4.7
v4.7-rc1
v4.7-rc2
v4.7-rc3
v4.7-rc4
v4.7-rc5
v4.7-rc6
v4.7-rc7
v4.8
v4.8-rc1
v4.8-rc2
v4.8-rc3
v4.8-rc4
v4.8-rc5
v4.8-rc6
v4.8-rc7
v4.8-rc8
v4.9
v4.9-rc1
v4.9-rc2
v4.9-rc3
v4.9-rc4
v4.9-rc5
v4.9-rc6
v4.9-rc7
v4.9-rc8
v5.*
v5.0
v5.0-rc1
v5.0-rc2
v5.0-rc3
v5.0-rc4
v5.0-rc5
v5.0-rc6
v5.0-rc7
v5.0-rc8
v5.1
v5.1-rc1
v5.1-rc2
v5.1-rc3
v5.1-rc4
v5.1-rc5
v5.1-rc6
v5.1-rc7
v5.10
v5.10-rc1
v5.10-rc2
v5.10-rc3
v5.10-rc4
v5.10-rc5
v5.10-rc6
v5.10-rc7
v5.11
v5.11-rc1
v5.11-rc2
v5.11-rc3
v5.11-rc4
v5.11-rc5
v5.11-rc6
v5.11-rc7
v5.12
v5.12-rc1
v5.12-rc1-dontuse
v5.12-rc2
v5.12-rc3
v5.12-rc4
v5.12-rc5
v5.12-rc6
v5.12-rc7
v5.12-rc8
v5.13
v5.13-rc1
v5.13-rc2
v5.13-rc3
v5.13-rc4
v5.13-rc5
v5.13-rc6
v5.13-rc7
v5.14
v5.14-rc1
v5.14-rc2
v5.14-rc3
v5.14-rc4
v5.14-rc5
v5.14-rc6
v5.14-rc7
v5.15
v5.15-rc1
v5.15-rc2
v5.15-rc3
v5.15-rc4
v5.15-rc5
v5.15-rc6
v5.15-rc7
v5.16
v5.16-rc1
v5.16-rc2
v5.16-rc3
v5.16-rc4
v5.16-rc5
v5.16-rc6
v5.16-rc7
v5.16-rc8
v5.17
v5.17-rc1
v5.17-rc2
v5.17-rc3
v5.17-rc4
v5.17-rc5
v5.17-rc6
v5.17-rc7
v5.17-rc8
v5.18
v5.18-rc1
v5.18-rc2
v5.18-rc3
v5.18-rc4
v5.18-rc5
v5.18-rc6
v5.18-rc7
v5.19
v5.19-rc1
v5.19-rc2
v5.19-rc3
v5.19-rc4
v5.19-rc5
v5.19-rc6
v5.19-rc7
v5.19-rc8
v5.2
v5.2-rc1
v5.2-rc2
v5.2-rc3
v5.2-rc4
v5.2-rc5
v5.2-rc6
v5.2-rc7
v5.3
v5.3-rc1
v5.3-rc2
v5.3-rc3
v5.3-rc4
v5.3-rc5
v5.3-rc6
v5.3-rc7
v5.3-rc8
v5.4
v5.4-rc1
v5.4-rc2
v5.4-rc3
v5.4-rc4
v5.4-rc5
v5.4-rc6
v5.4-rc7
v5.4-rc8
v5.5
v5.5-rc1
v5.5-rc2
v5.5-rc3
v5.5-rc4
v5.5-rc5
v5.5-rc6
v5.5-rc7
v5.6
v5.6-rc1
v5.6-rc2
v5.6-rc3
v5.6-rc4
v5.6-rc5
v5.6-rc6
v5.6-rc7
v5.7
v5.7-rc1
v5.7-rc2
v5.7-rc3
v5.7-rc4
v5.7-rc5
v5.7-rc6
v5.7-rc7
v5.8
v5.8-rc1
v5.8-rc2
v5.8-rc3
v5.8-rc4
v5.8-rc5
v5.8-rc6
v5.8-rc7
v5.9
v5.9-rc1
v5.9-rc2
v5.9-rc3
v5.9-rc4
v5.9-rc5
v5.9-rc6
v5.9-rc7
v5.9-rc8
v6.*
v6.0
v6.0-rc1
v6.0-rc2
v6.0-rc3
v6.0-rc4
v6.0-rc5
v6.0-rc6
v6.0-rc7
v6.1
v6.1-rc1
v6.1-rc2
v6.1-rc3
v6.1-rc4
v6.1-rc5
v6.1-rc6
v6.1-rc7
v6.1-rc8
v6.10
v6.10-rc1
v6.10-rc2
v6.10-rc3
v6.10-rc4
v6.10-rc5
v6.10-rc6
v6.10-rc7
v6.11
v6.11-rc1
v6.11-rc2
v6.11-rc3
v6.11-rc4
v6.11-rc5
v6.11-rc6
v6.11-rc7
v6.11.1
v6.11.2
v6.2
v6.2-rc1
v6.2-rc2
v6.2-rc3
v6.2-rc4
v6.2-rc5
v6.2-rc6
v6.2-rc7
v6.2-rc8
v6.3
v6.3-rc1
v6.3-rc2
v6.3-rc3
v6.3-rc4
v6.3-rc5
v6.3-rc6
v6.3-rc7
v6.4
v6.4-rc1
v6.4-rc2
v6.4-rc3
v6.4-rc4
v6.4-rc5
v6.4-rc6
v6.4-rc7
v6.5
v6.5-rc1
v6.5-rc2
v6.5-rc3
v6.5-rc4
v6.5-rc5
v6.5-rc6
v6.5-rc7
v6.6
v6.6-rc1
v6.6-rc2
v6.6-rc3
v6.6-rc4
v6.6-rc5
v6.6-rc6
v6.6-rc7
v6.7
v6.7-rc1
v6.7-rc2
v6.7-rc3
v6.7-rc4
v6.7-rc5
v6.7-rc6
v6.7-rc7
v6.7-rc8
v6.8
v6.8-rc1
v6.8-rc2
v6.8-rc3
v6.8-rc4
v6.8-rc5
v6.8-rc6
v6.8-rc7
v6.9
v6.9-rc1
v6.9-rc2
v6.9-rc3
v6.9-rc4
v6.9-rc5
v6.9-rc6
v6.9-rc7