sctp: clear new_transport when removing a peer
Summary
| CVE | CVE-2026-74586 |
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-22 16:16:30 UTC |
| Updated | 2026-08-22 16:16:30 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved:
sctp: clear new_transport when removing a peer
sctp_process_asconf_param() stores a newly added peer transport in
asoc->new_transport. After all parameters in the ASCONF chunk have been
processed, sctp_sf_do_asconf() uses this pointer to send a HEARTBEAT to the
new transport.
An authenticated ASCONF from a remote SCTP peer can add a transport and
remove it again with a wildcard DEL-IP parameter in the same chunk. The
wildcard deletion preserves the transport on which the ASCONF arrived, but
removes the newly added transport through
sctp_assoc_del_nonprimary_peers(). The removal does not clear
asoc->new_transport, leaving it pointing to the removed transport.
sctp_sf_do_asconf() then creates a HEARTBEAT whose chunk->transport points
to the removed transport without holding a transport reference. During
local address replacement, src_out_of_asoc_ok keeps this HEARTBEAT on
control_chunk_list. After the transport is freed by RCU, a successful
ASCONF_ACK for the replacement address releases the queued HEARTBEAT and
sctp_outq_select_transport() reads the freed transport's state.
The issue was found during a static audit of SCTP objects. With an
authenticated peer, the reproducer triggered the same KASAN report in 2
of 2 unpatched runs on a KASAN-enabled netdev/main kernel:
BUG: KASAN: slab-use-after-free in sctp_outq_select_transport
Read of size 4 at addr ffff88800b9bd95c by task python3/197
Call Trace:
sctp_outq_select_transport+0x549/0x8b0 [sctp]
sctp_outq_flush+0x306/0x2c60 [sctp]
sctp_transport_immediate_rtx+0xaf/0x260 [sctp]
sctp_process_asconf_ack+0xa48/0xf70 [sctp]
Allocated by task 197:
sctp_transport_new+0x68/0x650 [sctp]
sctp_assoc_add_peer+0x258/0x12a0 [sctp]
sctp_process_asconf+0x5e9/0x1090 [sctp]
Last potentially related work creation:
__call_rcu_common.constprop.0+0x77/0xb70
sctp_assoc_del_nonprimary_peers+0x7c/0xd0 [sctp]
sctp_process_asconf+0xd9c/0x1090 [sctp]
The first invalid access was a four-byte read of transport->state at
net/sctp/outqueue.c:833. The same reproducer completed the full
authenticated ASCONF and local-address replacement sequence with this
change without a KASAN report or oops.
Clear new_transport when its peer is removed, before it can be used to
create the HEARTBEAT. |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected 6af29ccc223b0feb6fc6112281c3fa3cdb1afddf c0f973bb5118dd1b146cda3fcc8af6f6057befec git |
Not specified |
| CNA |
Linux |
Linux |
affected 6af29ccc223b0feb6fc6112281c3fa3cdb1afddf 3b539b317cd052236fed0350364ff1268996ba46 git |
Not specified |
| CNA |
Linux |
Linux |
affected 6af29ccc223b0feb6fc6112281c3fa3cdb1afddf db9d8e3b670f841755bc2018f178472dc6064d27 git |
Not specified |
| CNA |
Linux |
Linux |
affected 6af29ccc223b0feb6fc6112281c3fa3cdb1afddf 31efa656cf6aface26e88f038c14f22ee6ca1500 git |
Not specified |
| CNA |
Linux |
Linux |
affected 6af29ccc223b0feb6fc6112281c3fa3cdb1afddf 291accf36febce751021888de5f15090f4875b56 git |
Not specified |
| CNA |
Linux |
Linux |
affected 6af29ccc223b0feb6fc6112281c3fa3cdb1afddf ca33df36aa0143a1d04f57d2086020c12e7eddb7 git |
Not specified |
| CNA |
Linux |
Linux |
affected 6af29ccc223b0feb6fc6112281c3fa3cdb1afddf 163847552a571bd55094291f4ffcdc1de0f14a7b git |
Not specified |
| CNA |
Linux |
Linux |
affected 6af29ccc223b0feb6fc6112281c3fa3cdb1afddf beb33f8ee1ca83acddb2a5ae80f3d22ec550b4c3 git |
Not specified |
| CNA |
Linux |
Linux |
affected 3.2 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 3.2 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.10.265 5.10.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.15.216 5.15.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.1.183 6.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.6.152 6.6.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.12.104 6.12.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.45 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.1.9 7.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/beb33f8ee1ca83acddb2a5ae80f3d22ec550b4c3 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/3b539b317cd052236fed0350364ff1268996ba46 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/31efa656cf6aface26e88f038c14f22ee6ca1500 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/163847552a571bd55094291f4ffcdc1de0f14a7b |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/c0f973bb5118dd1b146cda3fcc8af6f6057befec |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/db9d8e3b670f841755bc2018f178472dc6064d27 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/291accf36febce751021888de5f15090f4875b56 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/ca33df36aa0143a1d04f57d2086020c12e7eddb7 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.