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bpf: Add BPF_PROG_TYPE_CGROUP_SKB attach type enforcement in BPF_LINK_CREATE

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bpf_prog_attach uses attach_type_to_prog_type to enforce proper
attach type for BPF_PROG_TYPE_CGROUP_SKB. link_create uses
bpf_prog_get and relies on bpf_prog_attach_check_attach_type
to properly verify prog_type <> attach_type association.

Add missing attach_type enforcement for the link_create case.
Otherwise, it's currently possible to attach cgroup_skb prog
types to other cgroup hooks.

Fixes: af6eea5743 ("bpf: Implement bpf_link-based cgroup BPF program attachment")
Link: https://lore.kernel.org/bpf/0000000000004792a90615a1dde0@google.com/
Reported-by: syzbot+838346b979830606c854@syzkaller.appspotmail.com
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240426231621.2716876-2-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
This commit is contained in:
Stanislav Fomichev 2024-04-26 16:16:18 -07:00 committed by Martin KaFai Lau
parent b867247555
commit 543576ec15
1 changed files with 5 additions and 0 deletions
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5
kernel/bpf/syscall.c
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@ -3985,6 +3985,11 @@ static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
* check permissions at attach time.
*/
return -EPERM;
ptype = attach_type_to_prog_type(attach_type);
if (prog->type != ptype)
return -EINVAL;
return prog->enforce_expected_attach_type &&
prog->expected_attach_type != attach_type ?
-EINVAL : 0;