Re: [PATCH v2] uprobes: fix incorrect lockdep condition in filter_chain()
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Date: 2026-01-28 22:29:32
Also in:
linux-perf-users, lkml, stable
On Wed, 28 Jan 2026 10:16:11 -0800 Breno Leitao [off-list ref] wrote:
The list_for_each_entry_rcu() in filter_chain() uses
rcu_read_lock_trace_held() as the lockdep condition, but the function
holds consumer_rwsem, not the RCU trace lock.
This gives me the following output when running with some locking debug
option enabled:
kernel/events/uprobes.c:1141 RCU-list traversed in non-reader section!!
filter_chain
register_for_each_vma
uprobe_unregister_nosync
__probe_event_disable
Remove the incorrect lockdep condition since the rwsem provides
sufficient protection for the list traversal.Looks good to me. Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Thanks,
quoted hunk ↗ jump to hunk
Cc: stable@vger.kernel.org Fixes: cc01bd044e6a ("uprobes: travers uprobe's consumer list locklessly under SRCU protection") Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> --- Changes in v2: - updated the "fixes" tag (Oleg) - Link to v1: https://patch.msgid.link/20260128-uprobe_rcu-v1-1-d41316763799@debian.org --- kernel/events/uprobes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index d546d32390a81..726d13b375f3d 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c@@ -1138,7 +1138,7 @@ static bool filter_chain(struct uprobe *uprobe, struct mm_struct *mm) bool ret = false; down_read(&uprobe->consumer_rwsem); - list_for_each_entry_rcu(uc, &uprobe->consumers, cons_node, rcu_read_lock_trace_held()) { + list_for_each_entry(uc, &uprobe->consumers, cons_node) { ret = consumer_filter(uc, mm); if (ret) break;--- base-commit: 1f97d9dcf53649c41c33227b345a36902cbb08ad change-id: 20260128-uprobe_rcu-e21867ab4c1b Best regards, -- Breno Leitao [off-list ref]
-- Masami Hiramatsu (Google) [off-list ref]