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=1794063441; b=LXV0sgKpV1O5Rakie81WW+EtPf6kRFe96nKy8gN23NQscIO1IeZRAfWIF1Dpg39Pagct yTFevzrKsEg70wBIxRWWRtMxosHfbuiYzk+tz1mYE/GmTVrp0Qx0n7o0V8UX2v+4waTLA LpxUZmLqq000Riavj10D+rYfxAJ8ATB4gFUvmgnxa+MM8erV4kG+kO94yPOLoUD4JmNZG qc1+kvGCGE30a/1K+wDhnq+hEHbl+yXB3TSzYcXkjF4wVr5M23/0/X4XMHNizSjkyrCdI WaGD+F/WKvtCtEs7C3MVyzmRLP8+GWrs9fwoyCuIdo4UBMhkXzR5SQygnq3zAAcETiA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794063441; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=uU6Y5sE72yo2llXj4degy/lF5GVoIjE445YGhf3IOW4=; b=Q3kMvHcY9XgQVquZ2knWAdsaqOMO50PWbwYpp66XLhAd6WLo38PEg3PUwsop3wb3TcKC 6mn8yuLbjRLSn1fPuiGgTuisWpte5f/TxquQ5lj0OA6GGRrAx7yjfDIQ8Zz4mzGQe4EjE wpA2gRww7GmncfndhaBrl5JpUJel7XERrDDOyXEARMT40D+m+F4ujycrpzsp2iYoSReQU H/dDchBTklqu+2jQqTv0+/1zxZBFS8kBRliGvhNavPZr9eh6YN21oLfWOy9Tb2EqJJnxL l2R+imhXQSP/W7k67nmO0U/3S50T+OPJbBsi2mNpVLBKAIEAKkikFmIpNV3bDuPdHBg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=lwJGv9LJ; 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 9CBEC606A337; Sat, 7 Nov 2026 14:57:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=lwJGv9LJ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4D2D21F0089F; Sat, 7 Nov 2026 14:57:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794063441; bh=uU6Y5sE72yo2llXj4degy/lF5GVoIjE445YGhf3IOW4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lwJGv9LJjH96zMXK3taQrtKqZTwcyZHG63sR+6sIBoKgbDdMF156TxKCD5Krtzdc3 JbD02x1Pq2wxeGlPlYOsI2BOA1Dw6IGE4VdGV75zv/5/1CEInQPdm3CueVpEQHVIrJ pbW3a90wlDa4Ss9YYaQJX19uWCGeg74sYLT0G4AQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bui Viet Dung , Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 6.18 566/869] Bluetooth: hci_debugfs: Pin module for debugfs file operations Date: Sat, 7 Nov 2026 08:54:08 -0500 Message-ID: <20261107134912.463171324@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134852.069646174@linuxfoundation.org> References: <20261107134852.069646174@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bui Viet Dung [ Upstream commit 2a3e2287877b1ee40ffb80b7d769b633866533f3 ] An open debugfs file retains its file_operations pointer in the debugfs proxy state. However, the file_operations defined in hci_debugfs.c (use_debug_keys_fops, sc_only_mode_fops, ssp_debug_mode_fops, force_bredr_smp_fops, force_static_address_fops, force_no_mitm_fops, dut_mode_fops, vendor_diag_fops, and the DEFINE_QUIRK_ATTRIBUTE macro) have no .owner set to THIS_MODULE. As a result, full_proxy_open_regular() calls fops_get() which succeeds without taking a reference to the bluetooth module. When a userspace process opens any of these debugfs files, a subsequent controller removal and module unload (rmmod bluetooth) can succeed while the file descriptor remains open. When the userspace process subsequently closes the descriptor, full_proxy_release() accesses the already unmapped file_operations structure, triggering a kernel oops in full_proxy_release(): BUG: unable to handle page fault for address: fffffbfff8056f03 #PF: supervisor read access in kernel mode Oops: 0000 [#1] SMP KASAN NOPTI RIP: 0010:full_proxy_release+0x8e/0x140 Call Trace: __fput+0x39f/0xa60 fput_close_sync+0xff/0x200 __x64_sys_close+0x8c/0xf0 do_syscall_64+0x115/0x6a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f The issue was discovered via manual code audit of net/bluetooth/hci_debugfs.c and verified on a Linux 7.3-rc6 test VM with CONFIG_BT=m. Set .owner = THIS_MODULE on all debugfs file_operations tables in hci_debugfs.c so that debugfs keeps the module loaded until close has finished. Fixes: 0886aea6acd2 ("Bluetooth: Expose debug keys usage setting via debugfs") Cc: stable@vger.kernel.org Signed-off-by: Bui Viet Dung Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/hci_debugfs.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/net/bluetooth/hci_debugfs.c b/net/bluetooth/hci_debugfs.c index 9ae6d9224c3b7..807c9e0e212c9 100644 --- a/net/bluetooth/hci_debugfs.c +++ b/net/bluetooth/hci_debugfs.c @@ -68,6 +68,7 @@ static ssize_t __name ## _write(struct file *file, \ } \ \ static const struct file_operations __name ## _fops = { \ + .owner = THIS_MODULE, \ .open = simple_open, \ .read = __name ## _read, \ .write = __name ## _write, \ @@ -286,6 +287,7 @@ static ssize_t use_debug_keys_read(struct file *file, char __user *user_buf, } static const struct file_operations use_debug_keys_fops = { + .owner = THIS_MODULE, .open = simple_open, .read = use_debug_keys_read, .llseek = default_llseek, @@ -304,6 +306,7 @@ static ssize_t sc_only_mode_read(struct file *file, char __user *user_buf, } static const struct file_operations sc_only_mode_fops = { + .owner = THIS_MODULE, .open = simple_open, .read = sc_only_mode_read, .llseek = default_llseek, @@ -440,6 +443,7 @@ static ssize_t ssp_debug_mode_read(struct file *file, char __user *user_buf, } static const struct file_operations ssp_debug_mode_fops = { + .owner = THIS_MODULE, .open = simple_open, .read = ssp_debug_mode_read, .llseek = default_llseek, @@ -532,6 +536,7 @@ static ssize_t force_bredr_smp_write(struct file *file, } static const struct file_operations force_bredr_smp_fops = { + .owner = THIS_MODULE, .open = simple_open, .read = force_bredr_smp_read, .write = force_bredr_smp_write, @@ -781,6 +786,7 @@ static ssize_t force_static_address_write(struct file *file, } static const struct file_operations force_static_address_fops = { + .owner = THIS_MODULE, .open = simple_open, .read = force_static_address_read, .write = force_static_address_write, @@ -1184,6 +1190,7 @@ static ssize_t force_no_mitm_write(struct file *file, } static const struct file_operations force_no_mitm_fops = { + .owner = THIS_MODULE, .open = simple_open, .read = force_no_mitm_read, .write = force_no_mitm_write, @@ -1322,6 +1329,7 @@ static ssize_t dut_mode_write(struct file *file, const char __user *user_buf, } static const struct file_operations dut_mode_fops = { + .owner = THIS_MODULE, .open = simple_open, .read = dut_mode_read, .write = dut_mode_write, @@ -1378,6 +1386,7 @@ static ssize_t vendor_diag_write(struct file *file, const char __user *user_buf, } static const struct file_operations vendor_diag_fops = { + .owner = THIS_MODULE, .open = simple_open, .read = vendor_diag_read, .write = vendor_diag_write, -- 2.53.0