tipc: fix UAF in tipc_l2_send_msg()
In the Linux kernel, the following vulnerability has been resolved: tipc: fix UAF in tipc_l2_send_msg() Syzbot reported a slab-use-after-free in ipvlan_hard_header() when called from tipc_l2_send_msg(). The root cause is that tipc_disable_l2_media() calls synchronize_net() while b->media_ptr is still valid. This allows concurrent RCU readers to obtain the device pointer after synchronize_net() has finished. The pointer is cleared later in bearer_disable(), but without any subsequent synchronization, allowing the device to be freed while still in use by readers. Fix this by clearing b->media_ptr in tipc_disable_l2_media() before calling synchronize_net(). This is safe to do now because the call order in bearer_disable() was reversed in 0d051bf93c06 ("tipc: make bearer packet filtering generic") to call tipc_node_delete_links() (which needs the pointer) before disable_media(). https: //lore.kernel.org/netdev/6a2c1007.428ffe26.258b27.015d.GAE@google.com/T/#u
CVE-2026-74255
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-2026-74255
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": [
{
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"version": "282b3a056225b35024246f63feb91d769d714dad",
"lessThan": "609ced2301be1df7e7ed2ef47d1d916674e6ba3b",
"versionType": "git"
},
{
"status": "affected",
"version": "282b3a056225b35024246f63feb91d769d714dad",
"lessThan": "71aafa16d79b107b33837f60b6cbc7d0cb8c5708",
"versionType": "git"
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{
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"versionType": "git"
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{
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"versionType": "git"
},
{
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"lessThan": "aef12b5ce793dea6b3a97a58fd0f946000ae8945",
"versionType": "git"
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{
"status": "affected",
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"lessThan": "0d8a12d7143126afdf9fbe2e3d438650dd6603ed",
"versionType": "git"
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{
"status": "affected",
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"versionType": "git"
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{
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"lessThan": "f4c3d89fc986b0da196ddfc6cfe0ea5d5d08bec6",
"versionType": "git"
}
],
"programFiles": [
"net/tipc/bearer.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.4"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.4",
"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": "6.12.97",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/tipc/bearer.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-74255
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #33069 · Revision 1
- Added to Heist Feed
- Publisher date