bpf: tcp: fix double sock release on batch realloc
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.18.42, 7.1.6
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
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
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- Linux Linux
From 9794ac757a650dd594391192183c9caf939f8223 · fixed in c842882e4c5d2818b858d6baf3fd10958c93f729; From 1d7a82c1df5fc397eaca9c6b8c8f61aae9866ad4 · fixed in 7a6a6d2a127866935f87b55b557bc89693065462; From 36f955807ee4ede07e9410772f792e4cb4ec807b · fixed in f0c1810320b0dac228103fad7311e89532134d83; From cdec67a489d4fdae3e83e04fca0419136a83c4c2 · fixed in 9f27c4f0ae35b5390ce4f7a54d3501144e41a54d; From cdec67a489d4fdae3e83e04fca0419136a83c4c2 · fixed in 8a726e9585ffe7bfbfad2b5279277a00973970f3; From cdec67a489d4fdae3e83e04fca0419136a83c4c2 · fixed in 980a813452754f8001704744e92f7aa697c53dd3
- Linux Linux
6.17
- KernelLinux
From 6.17.0 · fixed in 6.18.42; From 6.19.0 · fixed in 7.1.6