bpf: Mark syscall helpers as sleepable

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: Mark syscall helpers as sleepable bpf_sys_bpf() executes the bpf(2) syscall body, which can take mutexes, allocate with GFP_KERNEL, and wait for an RCU grace period. bpf_sys_close() reaches close_fd() and filp_close(), which can sleep as well. Both helpers are limited to BPF_PROG_TYPE_SYSCALL, whose main program is sleepable. That does not make every callback sleepable: a syscall program can register a bpf_timer callback, and the verifier checks that callback in a non-sleepable context while retaining the syscall helper set. Without .might_sleep on the prototypes, such a callback can invoke bpf_sys_bpf() from hrtimer softirq context and trigger a scheduling-while-atomic failure. bpf_sys_close() is exposed through the same missing context check. Set .might_sleep on both prototypes so the existing helper-context check rejects them from timer callbacks and other atomic regions. Calls from the sleepable main body remain valid.

Timeline

1. Sep 25, 2026, 10:24 AM UTCCVE published
2. Oct 21, 2026, 12:54 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 79a7f8bdb159d9914b58740f3d31d602a6e4aca8 · fixed in 9496d857205e60241034b798d7745ff8830ba599; From 79a7f8bdb159d9914b58740f3d31d602a6e4aca8 · fixed in d8cfe9f71d302970ae393616960f2b3021d2b3b0; From 79a7f8bdb159d9914b58740f3d31d602a6e4aca8 · fixed in 65f636322ac402add6046c68e9ece77b9ffd71c9; From 79a7f8bdb159d9914b58740f3d31d602a6e4aca8 · fixed in 3408e98f06ce06ea6a58ca6c39da9c23f0029c06; From 79a7f8bdb159d9914b58740f3d31d602a6e4aca8 · fixed in d05524794240b52fdc3b6c1220dd05505715824d

• Linux Linux

  5.14

• KernelLinux

  From 5.14.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.114; From 6.13.0 · fixed in 6.18.57; From 6.19.0 · fixed in 7.2.7

References 5