Description

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/[email protected]

Classification

CVE ID: CVE-2024-56694

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.08% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

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

Timeline