Linux Trace Kernel
 help / color / mirror / Atom feed
From: Breno Leitao <leitao@debian.org>
To: Masami Hiramatsu <mhiramat@kernel.org>,
	Oleg Nesterov <oleg@redhat.com>,
	 Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	 Arnaldo Carvalho de Melo <acme@kernel.org>,
	 Namhyung Kim <namhyung@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	 Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	 Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
	 Adrian Hunter <adrian.hunter@intel.com>,
	 James Clark <james.clark@linaro.org>,
	Andrii Nakryiko <andrii@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
	 linux-perf-users@vger.kernel.org, kernel-team@meta.com,
	 stable@vger.kernel.org, Breno Leitao <leitao@debian.org>
Subject: [PATCH v2] uprobes: fix incorrect lockdep condition in filter_chain()
Date: Wed, 28 Jan 2026 10:16:11 -0800	[thread overview]
Message-ID: <20260128-uprobe_rcu-v2-1-994ea6d32730@debian.org> (raw)

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.

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 <leitao@debian.org>


             reply	other threads:[~2026-01-28 18:56 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-01-28 18:16 Breno Leitao [this message]
2026-01-28 22:29 ` [PATCH v2] uprobes: fix incorrect lockdep condition in filter_chain() Masami Hiramatsu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260128-uprobe_rcu-v2-1-994ea6d32730@debian.org \
    --to=leitao@debian.org \
    --cc=acme@kernel.org \
    --cc=adrian.hunter@intel.com \
    --cc=alexander.shishkin@linux.intel.com \
    --cc=andrii@kernel.org \
    --cc=irogers@google.com \
    --cc=james.clark@linaro.org \
    --cc=jolsa@kernel.org \
    --cc=kernel-team@meta.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-perf-users@vger.kernel.org \
    --cc=linux-trace-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mhiramat@kernel.org \
    --cc=mingo@redhat.com \
    --cc=namhyung@kernel.org \
    --cc=oleg@redhat.com \
    --cc=peterz@infradead.org \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox