af_unix: Fix garbage collector racing against connect()
Garbage collector does not take into account the risk of embryo getting
enqueued during the garbage collection. If such embryo has a peer that
carries SCM_RIGHTS, two consecutive passes of scan_children() may see a
different set of children. Leading to an incorrectly elevated inflight
count, and then a dangling pointer within the gc_inflight_list.
sockets are AF_UNIX/SOCK_STREAM
S is an unconnected socket
L is a listening in-flight socket bound to addr, not in fdtable
V's fd will be passed via sendmsg(), gets inflight count bumped
connect(S, addr) sendmsg(S, [V]); close(V) __unix_gc()
---------------- ------------------------- -----------
NS = unix_create1()
skb1 = sock_wmalloc(NS)
L = unix_find_other(addr)
unix_state_lock(L)
unix_peer(S) = NS
// V count=1 inflight=0
NS = unix_peer(S)
skb2 = sock_alloc()
skb_queue_tail(NS, skb2[V])
// V became in-flight
// V count=2 inflight=1
close(V)
// V count=1 inflight=1
// GC candidate condition met
for u in gc_inflight_list:
if (total_refs == inflight_refs)
add u to gc_candidates
// gc_candidates={L, V}
for u in gc_candidates:
scan_children(u, dec_inflight)
// embryo (skb1) was not
// reachable from L yet, so V's
// inflight remains unchanged
__skb_queue_tail(L, skb1)
unix_state_unlock(L)
for u in gc_candidates:
if (u.inflight)
scan_children(u, inc_inflight_move_tail)
// V count=1 inflight=2 (!)
If there is a GC-candidate listening socket, lock/unlock its state. This
makes GC wait until the end of any ongoing connect() to that socket. After
flipping the lock, a possibly SCM-laden embryo is already enqueued. And if
there is another embryo coming, it can not possibly carry SCM_RIGHTS. At
this point, unix_inflight() can not happen because unix_gc_lock is already
taken. Inflight graph remains unaffected.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-3840-1 | linux security update |
Debian DLA |
DLA-3842-1 | linux-5.10 security update |
Debian DSA |
DSA-5680-1 | linux security update |
Debian DSA |
DSA-5681-1 | linux security update |
Ubuntu USN |
USN-6893-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6893-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6893-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6895-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6895-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6895-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6895-4 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6896-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6896-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6896-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6896-4 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6896-5 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6898-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6898-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6898-3 | Linux kernel kernel vulnerabilities |
Ubuntu USN |
USN-6898-4 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6900-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6917-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6918-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6919-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6926-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6926-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6926-3 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-6927-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6938-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7019-1 | Linux kernel vulnerabilities |
Tue, 12 May 2026 12:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Tue, 23 Dec 2025 19:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Debian
Debian debian Linux Linux Linux linux Kernel |
|
| CPEs | cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.9:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.9:rc3:*:*:*:*:*:* |
|
| Vendors & Products |
Debian
Debian debian Linux Linux Linux linux Kernel |
|
| Metrics |
cvssV3_1
|
cvssV3_1
|
Fri, 11 Jul 2025 13:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
epss
|
epss
|
Fri, 22 Nov 2024 12:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Tue, 05 Nov 2024 10:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Wed, 30 Oct 2024 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| CPEs | cpe:/a:redhat:enterprise_linux:9 cpe:/o:redhat:enterprise_linux:9 |
Wed, 02 Oct 2024 15:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Redhat rhel Aus
Redhat rhel E4s Redhat rhel Tus |
|
| CPEs | cpe:/o:redhat:rhel_aus:8.6 cpe:/o:redhat:rhel_e4s:8.6 cpe:/o:redhat:rhel_tus:8.6 |
|
| Vendors & Products |
Redhat rhel Aus
Redhat rhel E4s Redhat rhel Tus |
Tue, 24 Sep 2024 11:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| CPEs | cpe:/o:redhat:enterprise_linux:8 cpe:/o:redhat:rhel_eus:8.8 |
Tue, 24 Sep 2024 06:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Redhat enterprise Linux
|
|
| CPEs | cpe:/a:redhat:enterprise_linux:8::nfv | |
| Vendors & Products |
Redhat enterprise Linux
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-12T11:50:40.454Z
Reserved: 2024-02-19T14:20:24.194Z
Link: CVE-2024-26923
Updated: 2024-08-02T00:21:05.612Z
Status : Modified
Published: 2024-04-25T06:15:57.160
Modified: 2026-05-12T12:16:26.473
Link: CVE-2024-26923
OpenCVE Enrichment
No data.
Debian DLA
Debian DSA
Ubuntu USN