CVE-2023-52621

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

bpf: Check rcu_read_lock_trace_held() before calling bpf map helpers

These three bpf_map_{lookup,update,delete}_elem() helpers are also available for sleepable bpf program, so add the corresponding lock assertion for sleepable bpf program, otherwise the following warning will be reported when a sleepable bpf program manipulates bpf map under interpreter mode (aka bpf_jit_enable=0):

WARNING: CPU: 3 PID: 4985 at kernel/bpf/helpers.c:40 …… CPU: 3 PID: 4985 Comm: test_progs Not tainted 6.6.0+ #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) …… RIP: 0010:bpf_map_lookup_elem+0x54/0x60 …… Call Trace: ? __warn+0xa5/0x240 ? bpf_map_lookup_elem+0x54/0x60 ? report_bug+0x1ba/0x1f0 ? handle_bug+0x40/0x80 ? exc_invalid_op+0x18/0x50 ? asm_exc_invalid_op+0x1b/0x20 ? __pfx_bpf_map_lookup_elem+0x10/0x10 ? rcu_lockdep_current_cpu_online+0x65/0xb0 ? rcu_is_watching+0x23/0x50 ? bpf_map_lookup_elem+0x54/0x60 ? __pfx_bpf_map_lookup_elem+0x10/0x10 ___bpf_prog_run+0x513/0x3b70 __bpf_prog_run32+0x9d/0xd0 ? __bpf_prog_enter_sleepable_recur+0xad/0x120 ? __bpf_prog_enter_sleepable_recur+0x3e/0x120 bpf_trampoline_6442580665+0x4d/0x1000 __x64_sys_getpgid+0x5/0x30 ? do_syscall_64+0x36/0xb0 entry_SYSCALL_64_after_hwframe+0x6e/0x76

Affected Software

References

• https://git.kernel.org/stable/c/169410eba271afc9f0fb476d996795aa26770c6d
• https://git.kernel.org/stable/c/483cb92334cd7f1d5387dccc0ab5d595d27a669d
• https://git.kernel.org/stable/c/c7f1b6146f4a46d727c0d046284c28b6882c6304
• https://git.kernel.org/stable/c/d6d6fe4bb105595118f12abeed4a7bdd450853f3