Overview
About vulnerability
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:
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 6 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CloudLinux 6 ELS , Oracle Linux 6 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS
- Affected packages:
- kernel @ 2.6.32 (+9 more)
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: