Re: [PATCH] uprobes: Free utask on dup_return_instance() failure
flat view
From: Oleg Nesterov <oleg@redhat.com>
Date: 2026-08-23 15:38:18
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linux-perf-users, lkml
(Add Andrii and Jiri) On 08/22, Keke Ming wrote:
dup_utask() installs the new uprobe_task in t->utask before copying return_instances. If dup_return_instance() fails, the partially copied utask is left attached to the child task.
Yes,
Free the partially copied utask before returning -ENOMEM.
But why? Note that uprobe_copy_process() warns but returns "void", too late to abort copy_process(). Perhaps we should change uprobe_copy_process() to kill the new child on failure, it will likely crash anyway. But I don't think this patch can make the things any better. Oleg.
quoted hunk ↗ jump to hunk
Signed-off-by: Keke Ming <redacted> --- kernel/events/uprobes.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index b25531331902..0c8a664a0fe5 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c@@ -2140,8 +2140,10 @@ static int dup_utask(struct task_struct *t, struct uprobe_task *o_utask) p = &n_utask->return_instances; for (o = o_utask->return_instances; o; o = o->next) { n = dup_return_instance(o); - if (!n) + if (!n) { + uprobe_free_utask(t); return -ENOMEM; + } /* if uprobe is non-NULL, we'll have an extra refcount for uprobe */ uprobe = hprobe_expire(&o->hprobe, true); --2.43.0