bpf: Fix reference count leak in bpf_prog_test_run_xdp()

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix reference count leak in bpf_prog_test_run_xdp() syzbot is reporting unregister_netdevice: waiting for sit0 to become free. Usage count = 2 problem. A debug printk() patch found that a refcount is obtained at xdp_convert_md_to_buff() from bpf_prog_test_run_xdp(). According to commit ec94670fcb3b ("bpf: Support specifying ingress via xdp_md context in BPF_PROG_TEST_RUN"), the refcount obtained by xdp_convert_md_to_buff() will be released by xdp_convert_buff_to_md(). Therefore, we can consider that the error handling path introduced by commit 1c1949982524 ("bpf: introduce frags support to bpf_prog_test_run_xdp()") forgot to call xdp_convert_buff_to_md().

Timeline

1. Jan 23, 2026, 3:24 PM UTCCVE published
2. Oct 15, 2026, 1:12 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 1c194998252469cad00a08bd9ef0b99fd255c260 · fixed in 368569bc546d3368ee9980ba79fc42fdff9a3365; From 1c194998252469cad00a08bd9ef0b99fd255c260 · fixed in 98676ee71fd4eafeb8be63c7f3f1905d40e03101; From 1c194998252469cad00a08bd9ef0b99fd255c260 · fixed in fb9ef40cccdbacce36029b305d0ef1e12e4fea38; From 1c194998252469cad00a08bd9ef0b99fd255c260 · fixed in 737be05a765761d7d7c9f7fe92274bd8e6f6951e; From 1c194998252469cad00a08bd9ef0b99fd255c260 · fixed in ec69daabe45256f98ac86c651b8ad1b2574489a7

• Linux Linux

  5.18

• KernelLinux

  From 5.18.0 · fixed in 6.1.161; From 6.2.0 · fixed in 6.6.121; From 6.7.0 · fixed in 6.12.66; From 6.13.0 · fixed in 6.18.6

References 5