From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794541878; b=zI4/+hg/ykZXYanSOvQT3kAQfWtaPQnki9mWDoqxUt3JEagWxJptIG4nUVZyan5YuwiA ew+G8f9qHfo27nHeN+cbNe5Lekw0Cf+BV52R1pHD6RzmNHAm8L2dQq4TRN78rV8nahuOL 5jlVsUDrvUs3TUTg4Jbi/eyhUsFVOUBkTda2sFWWHABYIQEUel90k978Itqgpw0I2aRk5 OOkCzEVbs3fJeNzaumlSzOEUO17Ox7oiZPU1P4xDH4fRDIWG0BHv6kT0AmWFH2uaKcpJA 1UyUoSzioy11Q4284WZVuySvVNabfpjoIyoL1IAgPLM9PgKP79n0ifqI+GMg11+Ld8g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794541878; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=I6jOQNaLzFFms70iQYBE9RRMQscvUFWqlwHWt0WG6zM=; b=PeG3IfffBzQWbRjTdvLcO96uUW9myBQ4LzEWohlADPE6v/ag5s5992GvRHvQBZUoXdhx oJHZDBIpwbU58mYKDhGVAKIi53LTHxFtizEu15vZPqWKwa9w1ZaRKlIscdiiO/YBZ+/6J 23OTd3FW4nXgpY186tq4InSyUPkANSnc4M8WKknZ8G/iVtW7TDZwjlAe6jbQWxTSIqW/v DLPiNdexvXR3YY2dXDRkAFgWnvZQnXwROcU2AXWZC1ynJZEP8qkX3q50KZ7hQR8PK9ONN PURAsq82qPzUQOVPvYWONfd15fE0/WU0I2AK+p+WHgoxMO5DEO6ydPzD3tpqG0xMFUg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=X3nWHGAZ; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EB24C606A327 for ; Fri, 13 Nov 2026 03:51:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=X3nWHGAZ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 588781F000C4; Fri, 13 Nov 2026 03:51:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794541877; bh=I6jOQNaLzFFms70iQYBE9RRMQscvUFWqlwHWt0WG6zM=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=X3nWHGAZp0Flsz+47po49maX/Rip9/8hHV2GGdL0c+eB7AXHJQcXAHvtXd5HEUmM6 bRzdL3imephurxRJoOxB4K4XQNHQ4Le+266KFsoYEUu1ueMT3+qM2KXc5DPA+a0w6n kvgdwNQVHhY28qllHrqYstXE4JqGPfrv8lkIZCmojsj4YidD1rtUWE64KuSsAuYclz NCmwzRP0r4EZOaCGJmDxrgrvuupAtf8wU0h3d3S1z/RbYEtDcf+6sGweAjpFd8MNj6 Zi70F20e54b/Cxc8dJFSQXGeZe00SSL5dU4a//S1BYKTIh3ekyDy9ltXk8jeVIHsEo 13DN7wxTyTPJg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v4] tracing: ring-buffer: fix stale reader-page link Reply-To: sashiko-reviews@lists.linux.dev To: "Haoli Zhang" <26031212468@stu.xidian.edu.cn> Cc: linux-trace-kernel@vger.kernel.org In-Reply-To: <20261113033612.1349-1-26031212468@stu.xidian.edu.cn> References: <20261113033612.1349-1-26031212468@stu.xidian.edu.cn> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 13 Nov 2026 03:51:16 +0000 X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Thank you for your contribution! Sashiko AI review found 1 potential issue to consider: - [Low] tracing: ring-buffer: reply text in changelog and missing Fixes trailer -- commit c4296f8629e0420816a4b5f1c95a30a1141d5523 Author: Haoli Zhang <26031212468@stu.xidian.edu.cn> > tracing: ring-buffer: fix stale reader-page link > > Hi Steve, > > Thanks for reviewing v3. I apologize for adding unnecessary NMI reader > coordination and skip handling. You noted the report is unrelated to NMI > reads. The lockless NMI path is only a best-effort crash-dump path. > I have removed that complexity and dropped the Fixes tag. > > The report shows rb_is_reader_page() dereferencing a freed page through > page->list.prev->next. During shrink, reader_page is detached from the > ring list and can retain a previous link to a page being removed. Redirect > that link to the surviving tail page while identifying pages to remove, > before any removed page is freed. > > This change does not add work to the normal writer fast path or alter NMI > reader behavior. > > Reported-by: syzbot+37e1793bdb0061ea3a47@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=3D37e1793bdb0061ea3a47 > Co-developed-by: Jinning Zhang <25031212117@stu.xidian.edu.cn> > Signed-off-by: Jinning Zhang <25031212117@stu.xidian.edu.cn> > Co-developed-by: Bin Yu > Signed-off-by: Bin Yu > Signed-off-by: Haoli Zhang <26031212468@stu.xidian.edu.cn> [Severity: Low] The opening paragraph ("Hi Steve, ...") is a personal reply to a reviewer and should go below the "---" separator line so it is not recorded in git history. Also, since commit 83f40318dab0 ("ring-buffer: Make removal of ring buffer pages atomic") rewrote rb_remove_pages() to unlink pages in place without calling rb_reset_cpu() to reinitialize cpu_buffer->reader_page->list, should this include: Fixes: 83f40318dab0 ("ring-buffer: Make removal of ring buffer pages atom= ic") --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261113033612.1349= -1-26031212468@stu.xidian.edu.cn?part=3D1