CVE-2024-56694

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

bpf: fix recursive lock when verdict program return SK_PASS

When the stream_verdict program returns SK_PASS, it places the received skb into its own receive queue, but a recursive lock eventually occurs, leading to an operating system deadlock. This issue has been present since v6.9.

sk_psock_strp_data_ready write_lock_bh(&sk->sk_callback_lock) strp_data_ready strp_read_sock read_sock -> tcp_read_sock strp_recv cb.rcv_msg -> sk_psock_strp_read # now stream_verdict return SK_PASS without peer sock assign __SK_PASS = sk_psock_map_verd(SK_PASS, NULL) sk_psock_verdict_apply sk_psock_skb_ingress_self sk_psock_skb_ingress_enqueue sk_psock_data_ready read_lock_bh(&sk->sk_callback_lock) <= dead lock

This topic has been discussed before, but it has not been fixed. Previous discussion: https://lore.kernel.org/all/6684a5864ec86_403d20898@john.notmuch

Weakness

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Affected Software

Extended Description

Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/25.html
• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/27.html

References

• https://git.kernel.org/stable/c/01f1b88acfd79103da0610b45471f6c88ea98d72
• https://git.kernel.org/stable/c/386efa339e08563dd33e83bc951aea5d407fe578
• https://git.kernel.org/stable/c/6694f7acd625ed854bf6342926e771d65dad7f69
• https://git.kernel.org/stable/c/8ca2a1eeadf09862190b2810697702d803ceef2d
• https://git.kernel.org/stable/c/da2bc8a0c8f3ac66fdf980fc59936f851a083561
• https://git.kernel.org/stable/c/f84c5ef6ca23cc2f72f3b830d74f67944684bb05