sctp: fix NULL deref on untransmitted RECONF completion
In the Linux kernel, the following vulnerability has been resolved: sctp: fix NULL deref on untransmitted RECONF completion sctp_process_strreset_outreq(), sctp_process_strreset_addstrm_out() and sctp_process_strreset_resp() complete a pending stream reconfiguration request by stopping the reconf timer on the transport it was sent on: t = asoc->strreset_chunk->transport; if (timer_delete(&t->reconf_timer)) sctp_transport_put(t); chunk->transport is assigned by __sctp_packet_append_chunk() when the chunk is appended to an outbound packet, and sctp_outq_flush_ctrl() arms the reconf timer at that same point. A request already published in asoc->strreset_chunk but not yet transmitted has neither, so completing it dereferences NULL. Two ways to get there. sctp_send_asconf_del_ip() sets asoc->src_out_of_asoc_ok without sending anything when the address being removed is the association's last one, and sctp_outq_flush_ctrl() then leaves every non-ASCONF control chunk queued; as only sctp_process_asconf_ack() clears that flag, it persists. An unprivileged process that removes such an address and then asks for a stream reset panics the kernel from softirq. A peer needs neither ASCONF nor local help: sctp_cmd_interpreter() uncorks the outqueue only once the whole packet has been processed, so a reply built while walking a RECONF chunk stays untransmitted for the rest of that walk, and one RECONF chunk carrying [Incoming SSN Reset Request, Outgoing SSN Reset Request, Response] -- or two
CVE-2026-89477
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-2026-89477
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": "81054476453640159149cb6704e834893e16736b",
"lessThan": "79ff751311e80fa0370007e46a79a6d601685e75",
"versionType": "git"
},
{
"status": "affected",
"version": "81054476453640159149cb6704e834893e16736b",
"lessThan": "53141db979687eae7dc6d29414cefc77034f967e",
"versionType": "git"
},
{
"status": "affected",
"version": "81054476453640159149cb6704e834893e16736b",
"lessThan": "68891125af5a5dfbca728809a16637a869bbe0df",
"versionType": "git"
},
{
"status": "affected",
"version": "81054476453640159149cb6704e834893e16736b",
"lessThan": "b2d6d873b4dfb5b84194061c4b40a1cd85b92ca4",
"versionType": "git"
},
{
"status": "affected",
"version": "81054476453640159149cb6704e834893e16736b",
"lessThan": "77ea60f2d24002c308f224db44a4542c466489af",
"versionType": "git"
},
{
"status": "affected",
"version": "81054476453640159149cb6704e834893e16736b",
"lessThan": "25419f516ea84b1e7d3d55aae5215ac86ece0c66",
"versionType": "git"
},
{
"status": "affected",
"version": "81054476453640159149cb6704e834893e16736b",
"lessThan": "0ee697defc0594f1da810ed75d9d643fb46f5318",
"versionType": "git"
},
{
"status": "affected",
"version": "81054476453640159149cb6704e834893e16736b",
"lessThan": "2db9bfa3e27bdea15e05ea70b56bad3d21e570ec",
"versionType": "git"
}
],
"programFiles": [
"net/sctp/stream.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.11"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.11",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.270",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.221",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.109",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/sctp/stream.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89477
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #35005 · Revision 1
- Added to Heist Feed
- Publisher date