diff options
| author | Gui-Dong Han <hanguidong02@gmail.com> | 2026-03-23 16:58:46 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-04-02 16:15:23 +0200 |
| commit | 7215e4552f31e53595eae56a834f7e286beecccc (patch) | |
| tree | d59d383d01d2089215447eff5a599cbde920788a /drivers/soundwire | |
| parent | 4afc929c0f74c4f22b055a82b371d50586da58ca (diff) | |
soundwire: debugfs: initialize firmware_file to empty string
Passing NULL to debugfs_create_str() causes a NULL pointer dereference,
and creating debugfs nodes with NULL string pointers is no longer
permitted.
Additionally, firmware_file is a global pointer. Previously, adding every
new slave blindly overwrote it with NULL.
Fix these issues by initializing firmware_file to an allocated empty
string once in the subsystem init path (sdw_debugfs_init), and freeing
it in the exit path. Existing driver code handles empty strings
correctly.
Fixes: fe46d2a4301d ("soundwire: debugfs: add interface to read/write commands")
Reported-by: yangshiguang <yangshiguang@xiaomi.com>
Closes: https://lore.kernel.org/lkml/17647e4c.d461.19b46144a4e.Coremail.yangshiguang1011@163.com/
Signed-off-by: Gui-Dong Han <hanguidong02@gmail.com>
Link: https://patch.msgid.link/20260323085930.88894-4-hanguidong02@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/soundwire')
| -rw-r--r-- | drivers/soundwire/debugfs.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/soundwire/debugfs.c b/drivers/soundwire/debugfs.c index ccc9670ef77c..2905ec19b838 100644 --- a/drivers/soundwire/debugfs.c +++ b/drivers/soundwire/debugfs.c @@ -358,8 +358,8 @@ void sdw_slave_debugfs_init(struct sdw_slave *slave) debugfs_create_file("go", 0200, d, slave, &cmd_go_fops); debugfs_create_file("read_buffer", 0400, d, slave, &read_buffer_fops); - firmware_file = NULL; - debugfs_create_str("firmware_file", 0200, d, &firmware_file); + if (firmware_file) + debugfs_create_str("firmware_file", 0200, d, &firmware_file); slave->debugfs = d; } @@ -371,10 +371,15 @@ void sdw_slave_debugfs_exit(struct sdw_slave *slave) void sdw_debugfs_init(void) { + if (!firmware_file) + firmware_file = kstrdup("", GFP_KERNEL); + sdw_debugfs_root = debugfs_create_dir("soundwire", NULL); } void sdw_debugfs_exit(void) { debugfs_remove_recursive(sdw_debugfs_root); + kfree(firmware_file); + firmware_file = NULL; } |