From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 38EFC168AD for ; Mon, 8 May 2023 11:21:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A92F0C433EF; Mon, 8 May 2023 11:21:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683544875; bh=71j0VKzSt/+EadfPe26/k+2pdDARW0LuA6gjjgicyDk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sBO0Li1FyKtzYNWTwyRsj7TE+FRTy1MD8QwlWWW6Zr2AOkyk756aaCD4MnRKt9Kq7 +H/WUj/2MylrBTGN8cpcwb6InMUNvf2zKKC5IQfyXwyqWxfR7rE7FM+tWKGdyepXKj YHJ3wA9j+mpgGh1E8ZVv5C1jYnxP5ksy1Y4Ub+PQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jishnu Prakash , Stephen Boyd , Sasha Levin Subject: [PATCH 6.3 552/694] spmi: Add a check for remove callback when removing a SPMI driver Date: Mon, 8 May 2023 11:46:27 +0200 Message-Id: <20230508094452.483522928@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094432.603705160@linuxfoundation.org> References: <20230508094432.603705160@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Jishnu Prakash [ Upstream commit b56eef3e16d888883fefab47425036de80dd38fc ] When removing a SPMI driver, there can be a crash due to NULL pointer dereference if it does not have a remove callback defined. This is one such call trace observed when removing the QCOM SPMI PMIC driver: dump_backtrace.cfi_jt+0x0/0x8 dump_stack_lvl+0xd8/0x16c panic+0x188/0x498 __cfi_slowpath+0x0/0x214 __cfi_slowpath+0x1dc/0x214 spmi_drv_remove+0x16c/0x1e0 device_release_driver_internal+0x468/0x79c driver_detach+0x11c/0x1a0 bus_remove_driver+0xc4/0x124 driver_unregister+0x58/0x84 cleanup_module+0x1c/0xc24 [qcom_spmi_pmic] __do_sys_delete_module+0x3ec/0x53c __arm64_sys_delete_module+0x18/0x28 el0_svc_common+0xdc/0x294 el0_svc+0x38/0x9c el0_sync_handler+0x8c/0xf0 el0_sync+0x1b4/0x1c0 If a driver has all its resources allocated through devm_() APIs and does not need any other explicit cleanup, it would not require a remove callback to be defined. Hence, add a check for remove callback presence before calling it when removing a SPMI driver. Link: https://lore.kernel.org/r/1671601032-18397-2-git-send-email-quic_jprakash@quicinc.com Fixes: 6f00f8c8635f ("mfd: qcom-spmi-pmic: Use devm_of_platform_populate()") Fixes: 5a86bf343976 ("spmi: Linux driver framework for SPMI") Signed-off-by: Jishnu Prakash Signed-off-by: Stephen Boyd Link: https://lore.kernel.org/r/20230413223834.4084793-7-sboyd@kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/spmi/spmi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/spmi/spmi.c b/drivers/spmi/spmi.c index 73551531ed437..dbc8585e8d6d0 100644 --- a/drivers/spmi/spmi.c +++ b/drivers/spmi/spmi.c @@ -350,7 +350,8 @@ static void spmi_drv_remove(struct device *dev) const struct spmi_driver *sdrv = to_spmi_driver(dev->driver); pm_runtime_get_sync(dev); - sdrv->remove(to_spmi_device(dev)); + if (sdrv->remove) + sdrv->remove(to_spmi_device(dev)); pm_runtime_put_noidle(dev); pm_runtime_disable(dev); -- 2.39.2