ipv4: ip_gre: make ipgre_header() robust
In the Linux kernel, the following vulnerability has been resolved: ipv4: ip_gre: make ipgre_header() robust Analog to commit db5b4e39c4e6 ("ip6_gre: make ip6gre_header() robust") Over the years, syzbot found many ways to crash the kernel in ipgre_header() [1]. This involves team or bonding drivers ability to dynamically change their dev->needed_headroom and/or dev->hard_header_len In this particular crash mld_newpack() allocated an skb with a too small reserve/headroom, and by the time mld_sendpack() was called, syzbot managed to attach an ipgre device. [1] skbuff: skb_under_panic: text:ffffffff89ea3cb7 len:2030915468 put:2030915372 head:ffff888058b43000 data:ffff887fdfa6e194 tail:0x120 end:0x6c0 dev:team0 kernel BUG at net/core/skbuff.c:213 ! Oops: invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 1 UID: 0 PID: 1322 Comm: kworker/1:9 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: mld mld_ifc_work RIP: 0010:skb_panic+0x157/0x160 net/core/skbuff.c:213 Call Trace: skb_under_panic net/core/skbuff.c:223 [inline] skb_push+0xc3/0xe0 net/core/skbuff.c:2641 ipgre_header+0x67/0x290 net/ipv4/ip_gre.c:897 dev_hard_header include/linux/netdevice.h:3436 [inline] neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247 NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318 mld_sendpack+0x8d4/0xe60 net/ipv
CVE-2026-23011
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-2026-23011
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": "c54419321455631079c7d6e60bc732dd0c5914c5",
"lessThan": "eeb9a521de40c6fadccc12fa5205e5a1b364d5a8",
"versionType": "git"
},
{
"status": "affected",
"version": "c54419321455631079c7d6e60bc732dd0c5914c5",
"lessThan": "8d5b6b2d79c1c22a5b0db1187a6439dff375a022",
"versionType": "git"
},
{
"status": "affected",
"version": "c54419321455631079c7d6e60bc732dd0c5914c5",
"lessThan": "2ecf0aa7cc262472a9599cc51ba02ada0897a17a",
"versionType": "git"
},
{
"status": "affected",
"version": "c54419321455631079c7d6e60bc732dd0c5914c5",
"lessThan": "06fe0801396a36cab865b34f666de1d65bc5ce8e",
"versionType": "git"
},
{
"status": "affected",
"version": "c54419321455631079c7d6e60bc732dd0c5914c5",
"lessThan": "aa57bfea4674e6da8104fa3a37760a6f5f255dad",
"versionType": "git"
},
{
"status": "affected",
"version": "c54419321455631079c7d6e60bc732dd0c5914c5",
"lessThan": "554201ed0a8f4d32e719f42caeaeb2735a9ed6ca",
"versionType": "git"
},
{
"status": "affected",
"version": "c54419321455631079c7d6e60bc732dd0c5914c5",
"lessThan": "e67c577d89894811ce4dcd1a9ed29d8b63476667",
"versionType": "git"
}
],
"programFiles": [
"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": "3.10"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.10",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.249",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.199",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.162",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.122",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.67",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.7",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "6.19",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/ipv4/ip_gre.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-23011
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #39730 · Revision 1
- Added to Heist Feed
- Publisher date