diff options
| author | Hou Tao <houtao1@huawei.com> | 2023-12-15 18:07:05 +0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2023-12-15 22:54:55 +0100 |
| commit | d6d1e6c17cab2dcb7b8530c599f00e7de906d380 (patch) | |
| tree | 8ec04ed42b761af3105deb4660c8ca566664e2ca /kernel/trace/bpf_trace.c | |
| parent | 8b2efe51ba85ca83460941672afac6fca4199df6 (diff) | |
bpf: Limit the number of kprobes when attaching program to multiple kprobes
An abnormally big cnt may also be assigned to kprobe_multi.cnt when
attaching multiple kprobes. It will trigger the following warning in
kvmalloc_node():
if (unlikely(size > INT_MAX)) {
WARN_ON_ONCE(!(flags & __GFP_NOWARN));
return NULL;
}
Fix the warning by limiting the maximal number of kprobes in
bpf_kprobe_multi_link_attach(). If the number of kprobes is greater than
MAX_KPROBE_MULTI_CNT, the attachment will fail and return -E2BIG.
Fixes: 0dcac2725406 ("bpf: Add multi kprobe link")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231215100708.2265609-3-houtao@huaweicloud.com
Diffstat (limited to 'kernel/trace/bpf_trace.c')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 75c05aea9fd9..97c0c49c40a0 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -43,6 +43,7 @@ rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) #define MAX_UPROBE_MULTI_CNT (1U << 20) +#define MAX_KPROBE_MULTI_CNT (1U << 20) #ifdef CONFIG_MODULES struct bpf_trace_module { @@ -2972,6 +2973,8 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr cnt = attr->link_create.kprobe_multi.cnt; if (!cnt) return -EINVAL; + if (cnt > MAX_KPROBE_MULTI_CNT) + return -E2BIG; size = cnt * sizeof(*addrs); addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); |