net: ip_gre: require CAP_NET_ADMIN in the device netns for changelink
In the Linux kernel, the following vulnerability has been resolved: net: ip_gre: require CAP_NET_ADMIN in the device netns for changelink A tunnel changelink() operates on at most two netns, dev_net(dev) and the tunnel link netns t->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in t->net can rewrite a tunnel that lives in t->net. Add rtnl_dev_link_net_capable() next to rtnl_get_net_ns_capable() in net/core/rtnetlink.c. It requires CAP_NET_ADMIN in the link netns and is skipped when the link netns is dev_net(dev), where the rtnl path already checked it. The other patches in this series use the same helper. Gate ipgre_changelink() and erspan_changelink() with it, at the top of the op before any attribute is parsed, because the parsers update live tunnel fields first. ipgre_netlink_parms() sets t->collect_md before ip_tunnel_changelink() runs. Commit 8b484efd5cb4 ("ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().") added the same check on the ioctl path. This adds it on RTM_NEWLINK.
CVE-2026-63829
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-2026-63829
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": "b57708add31494175be741ed3fd24023b50c3423",
"lessThan": "19275943d8fe903eb7b9aa53e380e41efd042ada",
"versionType": "git"
},
{
"status": "affected",
"version": "b57708add31494175be741ed3fd24023b50c3423",
"lessThan": "866b0f5ae599490bd496fd84581c68ac8b94e6af",
"versionType": "git"
},
{
"status": "affected",
"version": "b57708add31494175be741ed3fd24023b50c3423",
"lessThan": "92b766fc55156e0da2ecd0c2302c971118f8a229",
"versionType": "git"
},
{
"status": "affected",
"version": "b57708add31494175be741ed3fd24023b50c3423",
"lessThan": "e54c05ed3d9c28733fb9e5837219aca3691defa3",
"versionType": "git"
},
{
"status": "affected",
"version": "b57708add31494175be741ed3fd24023b50c3423",
"lessThan": "9831bc9ecb402957810c2045c663fbfe9b09e296",
"versionType": "git"
},
{
"status": "affected",
"version": "b57708add31494175be741ed3fd24023b50c3423",
"lessThan": "1697957eb0971d420dde42862b88eb43506a1105",
"versionType": "git"
},
{
"status": "affected",
"version": "b57708add31494175be741ed3fd24023b50c3423",
"lessThan": "47b5d3d506609b08b2e1f7c14f0b681a1953d572",
"versionType": "git"
},
{
"status": "affected",
"version": "b57708add31494175be741ed3fd24023b50c3423",
"lessThan": "8165f7ff57d9667d2bb477ef6af83ede7fed4ad7",
"versionType": "git"
}
],
"programFiles": [
"include/net/rtnetlink.h",
"net/core/rtnetlink.c",
"net/ipv4/ip_gre.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.95",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.38",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.3",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/net/rtnetlink.h",
"net/core/rtnetlink.c",
"net/ipv4/ip_gre.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-63829
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #40840 · Revision 1
- Added to Heist Feed
- Publisher date