From: Oleg Nesterov oleg@redhat.com

stable inclusion from stable-v6.6.54 commit 790c630ab0e7d7aba6d186581d4627c09fce60f3 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYPJ9 CVE: CVE-2024-47675

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

--------------------------------

commit 5fe6e308abaea082c20fbf2aa5df8e14495622cf upstream.

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.

Fixes: 89ae89f53d20 ("bpf: Add multi uprobe link") Closes: https://lore.kernel.org/all/000000000000382d39061f59f2dd@google.com/ Reported-by: syzbot+f7a1c2c2711e4a780f19@syzkaller.appspotmail.com Signed-off-by: Oleg Nesterov oleg@redhat.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Acked-by: Andrii Nakryiko andrii@kernel.org Acked-by: Jiri Olsa jolsa@kernel.org Tested-by: syzbot+f7a1c2c2711e4a780f19@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240813152524.GA7292@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Pu Lehui pulehui@huawei.com --- 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 cc29bf49f715..61e05b2bb384 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -3283,17 +3283,20 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr uprobes[i].ref_ctr_offset, &uprobes[i].consumer); if (err) { - bpf_uprobe_unregister(&path, 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(&path, uprobes, link->cnt); + error_free: kvfree(uprobes); kfree(link);