CVE-2026-64575
Received
Received - Intake
Double Free in Linux Kernel BPF
Vulnerability report for CVE-2026-64575, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-08-05
Last updated on: 2026-10-19
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
bpf: tcp: fix double sock release on batch realloc
bpf_iter_tcp_batch() releases the current batch via
bpf_iter_tcp_put_batch(), which drops the socket refs and rewrites
each slot with the socket cookie, then grows the batch. cur_sk/end_sk
are kept for bpf_iter_tcp_resume(), but on realloc failure the function
returns ERR_PTR() before resume runs, leaving cur_sk < end_sk over
slots that now hold cookies rather than sock pointers.
bpf_iter_tcp_seq_stop() then calls bpf_iter_tcp_put_batch() again and
dereferences a cookie as a struct sock.
Empty the batch on the failure path so stop() does not release it
again. The sockets were already freed by the first
bpf_iter_tcp_put_batch(), so nothing leaks, and a later read() rescans
the bucket from the start instead of skipping it. The sibling
GFP_NOWAIT failure path still holds real socket references and is left
for stop() to release.
BUG: KASAN: null-ptr-deref in __sock_gen_cookie
Read of size 8 at addr 0000000000000059 by task exploit
...
__sock_gen_cookie (net/core/sock_diag.c:28)
bpf_iter_tcp_put_batch (net/ipv4/tcp_ipv4.c:2918)
bpf_iter_tcp_seq_stop (net/ipv4/tcp_ipv4.c:3270)
bpf_seq_read (kernel/bpf/bpf_iter.c:205)
vfs_read (fs/read_write.c:572)
ksys_read (fs/read_write.c:716)
do_syscall_64
entry_SYSCALL_64_after_hwframe
Kernel panic - not syncing: Fatal exception
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-416 | The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. |
