In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix request_sock leak in sk lookup helpers
A customer reported a request_socket leak in a Calico cloud environment. We
found that a BPF program was doing a socket lookup with takes a refcnt on
the socket and that it was finding the request_socket but returning the parent
LISTEN socket via sk_to_full_sk() without decrementing the child request socket
1st, resulting in request_sock slab object leak. This patch retains the
existing behaviour of returning full socks to the caller but it also decrements
the child request_socket if one is present before doing so to prevent the leak.
Thanks to Curtis Taylor for all the help in diagnosing and testing this. And
thanks to Antoine Tenart for the reproducer and patch input.
v2 of this patch contains, refactor as per Daniel Borkmann's suggestions to
validate RCU flags on the listen socket so that it balances with bpf_sk_release()
and update comments as per Martin KaFai Lau's suggestion. One small change to
Daniels suggestion, put "sk = sk2" under "if (sk2 != sk)" to avoid an extra
instruction.
bpf: Fix request_sock leak in sk lookup helpers
A customer reported a request_socket leak in a Calico cloud environment. We
found that a BPF program was doing a socket lookup with takes a refcnt on
the socket and that it was finding the request_socket but returning the parent
LISTEN socket via sk_to_full_sk() without decrementing the child request socket
1st, resulting in request_sock slab object leak. This patch retains the
existing behaviour of returning full socks to the caller but it also decrements
the child request_socket if one is present before doing so to prevent the leak.
Thanks to Curtis Taylor for all the help in diagnosing and testing this. And
thanks to Antoine Tenart for the reproducer and patch input.
v2 of this patch contains, refactor as per Daniel Borkmann's suggestions to
validate RCU flags on the listen socket so that it balances with bpf_sk_release()
and update comments as per Martin KaFai Lau's suggestion. One small change to
Daniels suggestion, put "sk = sk2" under "if (sk2 != sk)" to avoid an extra
instruction.
Metrics
Affected Vendors & Products
Advisories
| Source | ID | Title |
|---|---|---|
EUVD |
EUVD-2022-54538 | In the Linux kernel, the following vulnerability has been resolved: bpf: Fix request_sock leak in sk lookup helpers A customer reported a request_socket leak in a Calico cloud environment. We found that a BPF program was doing a socket lookup with takes a refcnt on the socket and that it was finding the request_socket but returning the parent LISTEN socket via sk_to_full_sk() without decrementing the child request socket 1st, resulting in request_sock slab object leak. This patch retains the existing behaviour of returning full socks to the caller but it also decrements the child request_socket if one is present before doing so to prevent the leak. Thanks to Curtis Taylor for all the help in diagnosing and testing this. And thanks to Antoine Tenart for the reproducer and patch input. v2 of this patch contains, refactor as per Daniel Borkmann's suggestions to validate RCU flags on the listen socket so that it balances with bpf_sk_release() and update comments as per Martin KaFai Lau's suggestion. One small change to Daniels suggestion, put "sk = sk2" under "if (sk2 != sk)" to avoid an extra instruction. |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 24 Oct 2025 16:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | CWE-401 | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.19:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.19:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.19:rc3:*:*:*:*:*:* |
|
| Vendors & Products |
Linux
Linux linux Kernel |
Sat, 31 May 2025 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Redhat
Redhat enterprise Linux |
|
| CPEs | cpe:/a:redhat:enterprise_linux:9 cpe:/o:redhat:enterprise_linux:8 cpe:/o:redhat:enterprise_linux:9 |
|
| Vendors & Products |
Redhat
Redhat enterprise Linux |
Thu, 27 Feb 2025 01:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Wed, 26 Feb 2025 02:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: bpf: Fix request_sock leak in sk lookup helpers A customer reported a request_socket leak in a Calico cloud environment. We found that a BPF program was doing a socket lookup with takes a refcnt on the socket and that it was finding the request_socket but returning the parent LISTEN socket via sk_to_full_sk() without decrementing the child request socket 1st, resulting in request_sock slab object leak. This patch retains the existing behaviour of returning full socks to the caller but it also decrements the child request_socket if one is present before doing so to prevent the leak. Thanks to Curtis Taylor for all the help in diagnosing and testing this. And thanks to Antoine Tenart for the reproducer and patch input. v2 of this patch contains, refactor as per Daniel Borkmann's suggestions to validate RCU flags on the listen socket so that it balances with bpf_sk_release() and update comments as per Martin KaFai Lau's suggestion. One small change to Daniels suggestion, put "sk = sk2" under "if (sk2 != sk)" to avoid an extra instruction. | |
| Title | bpf: Fix request_sock leak in sk lookup helpers | |
| References |
|
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-04T08:43:29.495Z
Reserved: 2025-02-26T02:21:30.443Z
Link: CVE-2022-49697
No data.
Status : Analyzed
Published: 2025-02-26T07:01:44.450
Modified: 2025-10-24T15:50:50.077
Link: CVE-2022-49697
OpenCVE Enrichment
No data.
EUVD