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 D8ABF32D7EC; Mon, 27 Oct 2025 18:51:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761591064; cv=none; b=rYE5pAyGtRTOoeqeDTmNOTI48c8IwtVLs7Mwyp2N3R1fkB0ffR8q1nSjmeQyTzBXQnnkb0YOCCwAh1J91uP6nS3vC7Suzb8vQkC3AXOH/91gaKmSqVpcaDzY0SXFoblQG9v0TtIRDlnCBeSAHHCyFxJsS/O6TPJZAmO9+V6wffc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761591064; c=relaxed/simple; bh=tw4fUTuQrM1oYoICEz/lwU0KGysbc/4xqJA2f0nMPvA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=k8DYa39AfDCaOZ+x11sjVljcN62PcwxArGaySQvE2HRZv92HkGqCfbewOhgTKWAiBqvH/4rW/84e0SM66AAL18C8iPscjECl/BcbtRTomByDpaqBid5uRzqxkMU5J7A84yGHU8CiqG0bhEmjgjLXqMzIPl+zpmZQl3A7qFqvPNk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0SE24mXL; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="0SE24mXL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D17DFC4CEF1; Mon, 27 Oct 2025 18:51:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1761591063; bh=tw4fUTuQrM1oYoICEz/lwU0KGysbc/4xqJA2f0nMPvA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0SE24mXLu7fmKcQSv/Wrp4aJKyCJzWD50HHEE2nM8zaTV0u/GgPrd6AEiCQVX4k2d XgM10ernfVE1UvEWNvvQBoTDBtuwNXjEDwHrtehtMQTKxOiaBebbygQXWrz+S/bx6G p048hevaOYe5sJjvOmpsqbHNLeobjndnX5Z0YXMU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Wang Liang , Calvin Owens , Sasha Levin Subject: [PATCH 5.10 053/332] pps: fix warning in pps_register_cdev when register device fail Date: Mon, 27 Oct 2025 19:31:46 +0100 Message-ID: <20251027183526.021850059@linuxfoundation.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251027183524.611456697@linuxfoundation.org> References: <20251027183524.611456697@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wang Liang [ Upstream commit b0531cdba5029f897da5156815e3bdafe1e9b88d ] Similar to previous commit 2a934fdb01db ("media: v4l2-dev: fix error handling in __video_register_device()"), the release hook should be set before device_register(). Otherwise, when device_register() return error and put_device() try to callback the release function, the below warning may happen. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 4760 at drivers/base/core.c:2567 device_release+0x1bd/0x240 drivers/base/core.c:2567 Modules linked in: CPU: 1 UID: 0 PID: 4760 Comm: syz.4.914 Not tainted 6.17.0-rc3+ #1 NONE RIP: 0010:device_release+0x1bd/0x240 drivers/base/core.c:2567 Call Trace: kobject_cleanup+0x136/0x410 lib/kobject.c:689 kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0xe9/0x130 lib/kobject.c:737 put_device+0x24/0x30 drivers/base/core.c:3797 pps_register_cdev+0x2da/0x370 drivers/pps/pps.c:402 pps_register_source+0x2f6/0x480 drivers/pps/kapi.c:108 pps_tty_open+0x190/0x310 drivers/pps/clients/pps-ldisc.c:57 tty_ldisc_open+0xa7/0x120 drivers/tty/tty_ldisc.c:432 tty_set_ldisc+0x333/0x780 drivers/tty/tty_ldisc.c:563 tiocsetd drivers/tty/tty_io.c:2429 [inline] tty_ioctl+0x5d1/0x1700 drivers/tty/tty_io.c:2728 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x194/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x5f/0x2a0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e Before commit c79a39dc8d06 ("pps: Fix a use-after-free"), pps_register_cdev() call device_create() to create pps->dev, which will init dev->release to device_create_release(). Now the comment is outdated, just remove it. Thanks for the reminder from Calvin Owens, 'kfree_pps' should be removed in pps_register_source() to avoid a double free in the failure case. Link: https://lore.kernel.org/all/20250827065010.3208525-1-wangliang74@huawei.com/ Fixes: c79a39dc8d06 ("pps: Fix a use-after-free") Signed-off-by: Wang Liang Reviewed-By: Calvin Owens Link: https://lore.kernel.org/r/20250830075023.3498174-1-wangliang74@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/pps/kapi.c | 5 +---- drivers/pps/pps.c | 5 ++--- 2 files changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c index 92d1b62ea239d..e9389876229ea 100644 --- a/drivers/pps/kapi.c +++ b/drivers/pps/kapi.c @@ -109,16 +109,13 @@ struct pps_device *pps_register_source(struct pps_source_info *info, if (err < 0) { pr_err("%s: unable to create char device\n", info->name); - goto kfree_pps; + goto pps_register_source_exit; } dev_dbg(&pps->dev, "new PPS source %s\n", info->name); return pps; -kfree_pps: - kfree(pps); - pps_register_source_exit: pr_err("%s: unable to register source\n", info->name); diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c index ea966fc67d287..dbeb67ffebf33 100644 --- a/drivers/pps/pps.c +++ b/drivers/pps/pps.c @@ -375,6 +375,7 @@ int pps_register_cdev(struct pps_device *pps) pps->info.name); err = -EBUSY; } + kfree(pps); goto out_unlock; } pps->id = err; @@ -384,13 +385,11 @@ int pps_register_cdev(struct pps_device *pps) pps->dev.devt = MKDEV(pps_major, pps->id); dev_set_drvdata(&pps->dev, pps); dev_set_name(&pps->dev, "pps%d", pps->id); + pps->dev.release = pps_device_destruct; err = device_register(&pps->dev); if (err) goto free_idr; - /* Override the release function with our own */ - pps->dev.release = pps_device_destruct; - pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, pps_major, pps->id); -- 2.51.0