HID: picoLCD: check for fb_deferred_io_init() error

fb_deferred_io_init() allocates deferred I/O state, populating
info->fbdefio_state, or leaving it NULL if an error occurs.

Currently picolcd_init_framebuffer() ignores its return value.

Therefore if an error arises in fb_deferred_io_init() (for instance, due
to an allocation failure) info->fbdefio_state is left NULL.

When the file is subsequently opened, fb_open() will dereference a NULL
pointer (calling fb_deferred_io_open()).

Fix this by checking for the error.

Also correct cleanup ordering - defio is initialised after the sysfs file,
so cleanup defio first.

Fixes: 56c134f7f1 ("fbdev: Track deferred-I/O pages in pageref struct")
Cc: stable@vger.kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
Lorenzo Stoakes (ARM) 2026-09-26 14:17:01 +01:00 committed by Helge Deller
parent 5b234b0dd2
commit feade898fc

View File

@ -531,17 +531,23 @@ int picolcd_init_framebuffer(struct picolcd_data *data)
goto err_cleanup;
}
fb_deferred_io_init(info);
error = fb_deferred_io_init(info);
if (error) {
dev_err(dev, "failed to initialize deferred I/O\n");
goto err_sysfs;
}
error = register_framebuffer(info);
if (error) {
dev_err(dev, "failed to register framebuffer\n");
goto err_sysfs;
goto err_defio;
}
return 0;
err_defio:
fb_deferred_io_cleanup(info);
err_sysfs:
device_remove_file(dev, &dev_attr_fb_update_rate);
fb_deferred_io_cleanup(info);
err_cleanup:
data->fb_info = NULL;