If bpf_link_prime() fails, bpf_uprobe_multi_link_attach() goes to the error_free label and frees the array of bpf_uprobe's without calling bpf_uprobe_unregister().
This leaks bpf_uprobe->uprobe and worse, this frees bpf_uprobe->consumer without removing it from the uprobe->consumers list. Cc: [email protected] Fixes: 89ae89f53d20 ("bpf: Add multi uprobe link") Reported-by: [email protected] Closes: https://lore.kernel.org/all/[email protected]/ Tested-by: [email protected] Acked-by: Andrii Nakryiko <[email protected]> Signed-off-by: Oleg Nesterov <[email protected]> --- kernel/trace/bpf_trace.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 4e391daafa64..90cd30e9723e 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -3484,17 +3484,20 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr &uprobes[i].consumer); if (IS_ERR(uprobes[i].uprobe)) { err = PTR_ERR(uprobes[i].uprobe); - bpf_uprobe_unregister(uprobes, i); - goto error_free; + link->cnt = i; + goto error_unregister; } } err = bpf_link_prime(&link->link, &link_primer); if (err) - goto error_free; + goto error_unregister; return bpf_link_settle(&link_primer); +error_unregister: + bpf_uprobe_unregister(uprobes, link->cnt); + error_free: kvfree(uprobes); kfree(link); -- 2.25.1.362.g51ebf55
