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: <TASK> ?
__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 </TASK>

Notes