From: Leon Hwang <leon.hwang@linux.dev> mainline inclusion from mainline-v6.19-rc1 commit 6af6e49a76c9af7d42eb923703e7648cb2bf401a category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/12705 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... ---------------------------------------------------------------------- As [lru_,]percpu_hash maps support BPF_KPTR_{REF,PERCPU}, missing calls to 'bpf_obj_free_fields()' in 'pcpu_copy_value()' could cause the memory referenced by BPF_KPTR_{REF,PERCPU} fields to be held until the map gets freed. Fix this by calling 'bpf_obj_free_fields()' after 'copy_map_value[,_long]()' in 'pcpu_copy_value()'. Fixes: 65334e64a493 ("bpf: Support kptrs in percpu hashmap and percpu LRU hashmap") Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20251105151407.12723-2-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- kernel/bpf/hashtab.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index fdc74aeaa164..46e833e5666b 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -957,15 +957,21 @@ static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l) static void pcpu_copy_value(struct bpf_htab *htab, void __percpu *pptr, void *value, bool onallcpus) { + void *ptr; + if (!onallcpus) { /* copy true value_size bytes */ - copy_map_value(&htab->map, this_cpu_ptr(pptr), value); + ptr = this_cpu_ptr(pptr); + copy_map_value(&htab->map, ptr, value); + bpf_obj_free_fields(htab->map.record, ptr); } else { u32 size = round_up(htab->map.value_size, 8); int off = 0, cpu; for_each_possible_cpu(cpu) { - copy_map_value_long(&htab->map, per_cpu_ptr(pptr, cpu), value + off); + ptr = per_cpu_ptr(pptr, cpu); + copy_map_value_long(&htab->map, ptr, value + off); + bpf_obj_free_fields(htab->map.record, ptr); off += size; } } -- 2.34.1