l2tp: fix tunnel and session refcount leak on seq_file release
In the Linux kernel, the following vulnerability has been resolved: l2tp: fix tunnel and session refcount leak on seq_file release In pppol2tp_proc_open() and l2tp_dfs_seq_open(), iteration state (pd->tunnel and pd->session) is kept in seq_file private data to allow iteration across multiple read() system calls. However, if userspace closes /proc/net/pppol2tp or /sys/kernel/debug/l2tp/tunnels before reading to end-of-file (EOF), any tunnel or session reference stored in pd->tunnel / pd->session is left un-dropped when seq_file private data is freed. Fix this by dropping any remaining pd->tunnel and pd->session references in pppol2tp_proc_release() and l2tp_dfs_seq_release() when closing the file.
CVE-2026-74735
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-74735
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "0e0c3fee3a59a387aeecc4fca6f3a2e9615a5443",
"lessThan": "bd897e414451fb34dfdf08b31899180e5ab7149b",
"versionType": "git"
},
{
"status": "affected",
"version": "0e0c3fee3a59a387aeecc4fca6f3a2e9615a5443",
"lessThan": "bdf83613781956cc39798ed08321f74ab0467f4d",
"versionType": "git"
},
{
"status": "affected",
"version": "0e0c3fee3a59a387aeecc4fca6f3a2e9615a5443",
"lessThan": "8c4fde01bcf91f22b9c7ded8c3e14addd7ddd500",
"versionType": "git"
},
{
"status": "affected",
"version": "0e0c3fee3a59a387aeecc4fca6f3a2e9615a5443",
"lessThan": "ebe2774e956482dd3c70b8991f6f7654356339e6",
"versionType": "git"
},
{
"status": "affected",
"version": "0e0c3fee3a59a387aeecc4fca6f3a2e9615a5443",
"lessThan": "9006c116dd111d457bf5d074990210f70a4ad2c8",
"versionType": "git"
},
{
"status": "affected",
"version": "f6104e9ae04462523c372928b1173766a771ef95",
"versionType": "git"
},
{
"status": "affected",
"version": "7f8e401f9e612df2a95c1ef76217c00181389bb5",
"versionType": "git"
},
{
"status": "affected",
"version": "c712ed63e9b33d9a282fbd92ce25c64918c3129f",
"versionType": "git"
},
{
"status": "affected",
"version": "9a8863e8a8def9d88583cd9c60db38a008e6b8cf",
"versionType": "git"
},
{
"status": "affected",
"version": "3.16.60",
"lessThan": "3.17",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.16.6",
"lessThan": "4.17",
"versionType": "semver"
}
],
"programFiles": [
"net/l2tp/l2tp_debugfs.c",
"net/l2tp/l2tp_ppp.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.17"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.17",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.10",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/l2tp/l2tp_debugfs.c",
"net/l2tp/l2tp_ppp.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-74735
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #46598 · Revision 1
- Added to Heist Feed
- Publisher date