Tracker / CVE-2023-53221
CVE-2023-53221
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix memleak due to fentry attach failure If it fails to attach fentry, the allocated bpf trampoline image will be left in the system. That can be verified by checking /proc/kallsyms. This meamleak can be verified by a simple bpf program as follows: SEC("fentry/trap_init") int fentry_run() { return 0; } It will fail to attach trap_init because this function is freed after kernel init, and then we can find the trampoline image is left in the system by checking /proc/kallsyms. $ tail /proc/kallsyms ffffffffc0613000 t bpf_trampoline_6442453466_1 [bpf] ffffffffc06c3000 t bpf_trampoline_6442453466_1 [bpf] $ bpftool btf dump file /sys/kernel/btf/vmlinux | grep "FUNC 'trap_init'" [2522] FUNC 'trap_init' type_id=119 linkage=static $ echo $((6442453466 & 0x7fffffff)) 2522 Note that there are two left bpf trampoline images, that is because the libbpf will fallback to raw tracepoint if -EINVAL is returned.
Affected products and versions
| linux | linux_kernel |
|---|---|
| linux | linux_kernel · 5.10.28 → 5.11 |
| linux | linux_kernel · 5.11.11 → 5.12 |
| linux | linux_kernel · 5.12.1 → 6.1.39 |
| linux | linux_kernel · 6.2 → 6.3.13 |
| linux | linux_kernel · 6.4 → 6.4.4 |