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bpf: Fix uprobe multi pid filter check

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Uprobe multi link does its own process (thread leader) filtering before
running the bpf program by comparing task's vm pointers.

But as Oleg pointed out there can be processes sharing the vm (CLONE_VM),
so we can't just compare task->vm pointers, but instead we need to use
same_thread_group call.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/bpf/20240905115124.1503998-2-jolsa@kernel.org
This commit is contained in:
Jiri Olsa 2024-09-05 14:51:21 +03:00 committed by Andrii Nakryiko
parent aa01d13eec
commit 900f362e20
1 changed files with 1 additions and 1 deletions
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2
kernel/trace/bpf_trace.c
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@ -3207,7 +3207,7 @@ static int uprobe_prog_run(struct bpf_uprobe *uprobe,
struct bpf_run_ctx *old_run_ctx;
int err = 0;
if (link->task && current->mm != link->task->mm)
if (link->task && !same_thread_group(current, link->task))
return 0;
if (sleepable)