Hi all,
These patches fix a few bugs in init and deinit for the bluetooth module. I ran into the first one when I started running a kernel with debugfs disabled on my laptop, and I ran into the next two when I was working on the fix for the first one.
v2: * Move iso_exit() call to bt_exit() (Luiz Augusto von Dentz)
Aaron Thompson (3): Bluetooth: ISO: Fix multiple init when debugfs is disabled Bluetooth: Call iso_exit() on module unload Bluetooth: Remove debugfs directory on module init failure
net/bluetooth/af_bluetooth.c | 3 +++ net/bluetooth/iso.c | 6 +----- 2 files changed, 4 insertions(+), 5 deletions(-)
base-commit: 9852d85ec9d492ebef56dc5f229416c925758edc
From: Aaron Thompson dev@aaront.org
If bt_debugfs is not created successfully, which happens if either CONFIG_DEBUG_FS or CONFIG_DEBUG_FS_ALLOW_ALL is unset, then iso_init() returns early and does not set iso_inited to true. This means that a subsequent call to iso_init() will result in duplicate calls to proto_register(), bt_sock_register(), etc.
With CONFIG_LIST_HARDENED and CONFIG_BUG_ON_DATA_CORRUPTION enabled, the duplicate call to proto_register() triggers this BUG():
list_add double add: new=ffffffffc0b280d0, prev=ffffffffbab56250, next=ffffffffc0b280d0. ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:35! Oops: invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 2 PID: 887 Comm: bluetoothd Not tainted 6.10.11-1-ao-desktop #1 RIP: 0010:__list_add_valid_or_report+0x9a/0xa0 ... __list_add_valid_or_report+0x9a/0xa0 proto_register+0x2b5/0x340 iso_init+0x23/0x150 [bluetooth] set_iso_socket_func+0x68/0x1b0 [bluetooth] kmem_cache_free+0x308/0x330 hci_sock_sendmsg+0x990/0x9e0 [bluetooth] __sock_sendmsg+0x7b/0x80 sock_write_iter+0x9a/0x110 do_iter_readv_writev+0x11d/0x220 vfs_writev+0x180/0x3e0 do_writev+0xca/0x100 ...
This change removes the early return. The check for iso_debugfs being NULL was unnecessary, it is always NULL when iso_inited is false.
Cc: stable@vger.kernel.org Fixes: ccf74f2390d6 ("Bluetooth: Add BTPROTO_ISO socket type") Signed-off-by: Aaron Thompson dev@aaront.org --- net/bluetooth/iso.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c index d5e00d0dd1a0..c9eefb43bf47 100644 --- a/net/bluetooth/iso.c +++ b/net/bluetooth/iso.c @@ -2301,13 +2301,9 @@ int iso_init(void)
hci_register_cb(&iso_cb);
- if (IS_ERR_OR_NULL(bt_debugfs)) - return 0; - - if (!iso_debugfs) { + if (!IS_ERR_OR_NULL(bt_debugfs)) iso_debugfs = debugfs_create_file("iso", 0444, bt_debugfs, NULL, &iso_debugfs_fops); - }
iso_inited = true;
From: Aaron Thompson dev@aaront.org
If iso_init() has been called, iso_exit() must be called on module unload. Without that, the struct proto that iso_init() registered with proto_register() becomes invalid, which could cause unpredictable problems later. In my case, with CONFIG_LIST_HARDENED and CONFIG_BUG_ON_DATA_CORRUPTION enabled, loading the module again usually triggers this BUG():
list_add corruption. next->prev should be prev (ffffffffb5355fd0), but was 0000000000000068. (next=ffffffffc0a010d0). ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:29! Oops: invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 4159 Comm: modprobe Not tainted 6.10.11-4+bt2-ao-desktop #1 RIP: 0010:__list_add_valid_or_report+0x61/0xa0 ... __list_add_valid_or_report+0x61/0xa0 proto_register+0x299/0x320 hci_sock_init+0x16/0xc0 [bluetooth] bt_init+0x68/0xd0 [bluetooth] __pfx_bt_init+0x10/0x10 [bluetooth] do_one_initcall+0x80/0x2f0 do_init_module+0x8b/0x230 __do_sys_init_module+0x15f/0x190 do_syscall_64+0x68/0x110 ...
Cc: stable@vger.kernel.org Fixes: ccf74f2390d6 ("Bluetooth: Add BTPROTO_ISO socket type") Signed-off-by: Aaron Thompson dev@aaront.org --- net/bluetooth/af_bluetooth.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c index 67604ccec2f4..9425d0680844 100644 --- a/net/bluetooth/af_bluetooth.c +++ b/net/bluetooth/af_bluetooth.c @@ -830,6 +830,8 @@ static int __init bt_init(void)
static void __exit bt_exit(void) { + iso_exit(); + mgmt_exit();
sco_exit();
From: Aaron Thompson dev@aaront.org
If bt_init() fails, the debugfs directory currently is not removed. If the module is loaded again after that, the debugfs directory is not set up properly due to the existing directory.
# modprobe bluetooth # ls -laF /sys/kernel/debug/bluetooth total 0 drwxr-xr-x 2 root root 0 Sep 27 14:26 ./ drwx------ 31 root root 0 Sep 27 14:25 ../ -r--r--r-- 1 root root 0 Sep 27 14:26 l2cap -r--r--r-- 1 root root 0 Sep 27 14:26 sco # modprobe -r bluetooth # ls -laF /sys/kernel/debug/bluetooth ls: cannot access '/sys/kernel/debug/bluetooth': No such file or directory #
# modprobe bluetooth modprobe: ERROR: could not insert 'bluetooth': Invalid argument # dmesg | tail -n 6 Bluetooth: Core ver 2.22 NET: Registered PF_BLUETOOTH protocol family Bluetooth: HCI device and connection manager initialized Bluetooth: HCI socket layer initialized Bluetooth: Faking l2cap_init() failure for testing NET: Unregistered PF_BLUETOOTH protocol family # ls -laF /sys/kernel/debug/bluetooth total 0 drwxr-xr-x 2 root root 0 Sep 27 14:31 ./ drwx------ 31 root root 0 Sep 27 14:26 ../ #
# modprobe bluetooth # dmesg | tail -n 7 Bluetooth: Core ver 2.22 debugfs: Directory 'bluetooth' with parent '/' already present! NET: Registered PF_BLUETOOTH protocol family Bluetooth: HCI device and connection manager initialized Bluetooth: HCI socket layer initialized Bluetooth: L2CAP socket layer initialized Bluetooth: SCO socket layer initialized # ls -laF /sys/kernel/debug/bluetooth total 0 drwxr-xr-x 2 root root 0 Sep 27 14:31 ./ drwx------ 31 root root 0 Sep 27 14:26 ../ #
Cc: stable@vger.kernel.org Fixes: ffcecac6a738 ("Bluetooth: Create root debugfs directory during module init") Signed-off-by: Aaron Thompson dev@aaront.org --- net/bluetooth/af_bluetooth.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c index 9425d0680844..e39fba5565c5 100644 --- a/net/bluetooth/af_bluetooth.c +++ b/net/bluetooth/af_bluetooth.c @@ -825,6 +825,7 @@ static int __init bt_init(void) bt_sysfs_cleanup(); cleanup_led: bt_leds_cleanup(); + debugfs_remove_recursive(bt_debugfs); return err; }
Hello:
This series was applied to bluetooth/bluetooth-next.git (master) by Luiz Augusto von Dentz luiz.von.dentz@intel.com:
On Fri, 4 Oct 2024 23:04:07 +0000 you wrote:
Hi all,
These patches fix a few bugs in init and deinit for the bluetooth module. I ran into the first one when I started running a kernel with debugfs disabled on my laptop, and I ran into the next two when I was working on the fix for the first one.
[...]
Here is the summary with links: - [v2,1/3] Bluetooth: ISO: Fix multiple init when debugfs is disabled https://git.kernel.org/bluetooth/bluetooth-next/c/6259a9d4578d - [v2,2/3] Bluetooth: Call iso_exit() on module unload https://git.kernel.org/bluetooth/bluetooth-next/c/d18b99bb8795 - [v2,3/3] Bluetooth: Remove debugfs directory on module init failure https://git.kernel.org/bluetooth/bluetooth-next/c/f5a04a514aa2
You are awesome, thank you!
linux-stable-mirror@lists.linaro.org
-
Aaron Thompson -
patchwork-bot+bluetooth＠kernel.org