CVE-2025-21683

bpf: Fix bpf_sk_select_reuseport() memory leak

State: Published
Severity: 5.5 Medium
Published: Jan 31, 2025
Updated: Oct 15, 2026
Reserved: Dec 29, 2024

Description

In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix bpf_sk_select_reuseport() memory leak

As pointed out in the original comment, lookup in sockmap can return a TCP ESTABLISHED socket. Such TCP socket may have had SO_ATTACH_REUSEPORT_EBPF set before it was ESTABLISHED. In other words, a non-NULL sk_reuseport_cb does not imply a non-refcounted socket.

Drop sk's reference in both error paths.

unreferenced object 0xffff888101911800 (size 2048): comm "test_progs", pid 44109, jiffies 4297131437 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 80 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc 9336483b): __kmalloc_noprof+0x3bf/0x560 __reuseport_alloc+0x1d/0x40 reuseport_alloc+0xca/0x150 reuseport_attach_prog+0x87/0x140 sk_reuseport_attach_bpf+0xc8/0x100 sk_setsockopt+0x1181/0x1990 do_sock_setsockopt+0x12b/0x160 __sys_setsockopt+0x7b/0xc0 __x64_sys_setsockopt+0x1b/0x30 do_syscall_64+0x93/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Scores

CVSS	Score	Vector	Source
3.1	5.5 Medium	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H	CISA-ADP

Weaknesses

CWE-401 Missing Release of Memory after Effective Lifetime

Affected Products

Product	Versions
LinuxLinux	64d85290d79c0677edb5a8ee2295b36c022fa5df to before bb36838dac7bb334a3f3d7eb29875593ec9473fcAffected 64d85290d79c0677edb5a8ee2295b36c022fa5df to before 0ab52a8ca6e156a64c51b5e7456cac9a0ebfd9bfAffected 64d85290d79c0677edb5a8ee2295b36c022fa5df to before d0a3b3d1176d39218b8edb2a2d03164942ab9ccdAffected 64d85290d79c0677edb5a8ee2295b36c022fa5df to before b02e70be498b138e9c21701c2f33f4018ca7cd5eAffected 64d85290d79c0677edb5a8ee2295b36c022fa5df to before cccd51dd22574216e64e5d205489e634f86999f3Affected 64d85290d79c0677edb5a8ee2295b36c022fa5df to before b3af60928ab9129befa65e6df0310d27300942bfAffected
LinuxLinux	5.8Affected before 5.8Not affected 5.10.234 through 5.10.Not affected 5.15.177 through 5.15.Not affected 6.1.127 through 6.1.Not affected 6.6.74 through 6.6.Not affected 6.12.11 through 6.12.*Not affected 6.13 and laterNot affected

Product

Versions

LinuxLinux

64d85290d79c0677edb5a8ee2295b36c022fa5df to before bb36838dac7bb334a3f3d7eb29875593ec9473fcAffected
64d85290d79c0677edb5a8ee2295b36c022fa5df to before 0ab52a8ca6e156a64c51b5e7456cac9a0ebfd9bfAffected
64d85290d79c0677edb5a8ee2295b36c022fa5df to before d0a3b3d1176d39218b8edb2a2d03164942ab9ccdAffected
64d85290d79c0677edb5a8ee2295b36c022fa5df to before b02e70be498b138e9c21701c2f33f4018ca7cd5eAffected
64d85290d79c0677edb5a8ee2295b36c022fa5df to before cccd51dd22574216e64e5d205489e634f86999f3Affected
64d85290d79c0677edb5a8ee2295b36c022fa5df to before b3af60928ab9129befa65e6df0310d27300942bfAffected

LinuxLinux

5.8Affected
before 5.8Not affected
5.10.234 through 5.10.*Not affected
5.15.177 through 5.15.*Not affected
6.1.127 through 6.1.*Not affected
6.6.74 through 6.6.*Not affected
6.12.11 through 6.12.*Not affected
6.13 and laterNot affected

References

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