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bpf: Limit the number of uprobes when attaching program to multiple uprobes

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[ Upstream commit 8b2efe51ba85ca83460941672afac6fca4199df6 ]

An abnormally big cnt may be passed to link_create.uprobe_multi.cnt,
and 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 uprobes in
bpf_uprobe_multi_link_attach(). If the number of uprobes is greater than
MAX_UPROBE_MULTI_CNT, the attachment will return -E2BIG.

Fixes: 89ae89f53d20 ("bpf: Add multi uprobe link")
Reported-by: Xingwei Lee <xrivendell7@gmail.com>
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>
Closes: https://lore.kernel.org/bpf/CABOYnLwwJY=yFAGie59LFsUsBAgHfroVqbzZ5edAXbFE3YiNVA@mail.gmail.com
Link: https://lore.kernel.org/bpf/20231215100708.2265609-2-houtao@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Hou Tao 2023-12-15 18:07:04 +08:00 committed by Greg Kroah-Hartman
parent 849ca053be
commit 5735054af3
1 changed files with 4 additions and 0 deletions
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4
kernel/trace/bpf_trace.c
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@ -41,6 +41,8 @@
#define bpf_event_rcu_dereference(p) \
rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
#define MAX_UPROBE_MULTI_CNT (1U << 20)
#ifdef CONFIG_MODULES
struct bpf_trace_module {
struct module *module;
@ -3198,6 +3200,8 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
if (!upath || !uoffsets || !cnt)
return -EINVAL;
if (cnt > MAX_UPROBE_MULTI_CNT)
return -E2BIG;
uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets);
ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies);