From: Stian Skjelstad stian.skjelstad@gmail.com
* maximum write size was calculated in words (16bit), but checked against byte-size length. This causes memcpy later to overflow the buffer (normally by up to 12KB). * remove a double free (by marking free'd data with NULL)
* mmap returns MMAP_FAILED on error, not NULL
I suspect that this plugin/driver might have other issues aswell, since I am unable to find any logic for checking DSP buffer status, and no implementation for odelay reporting.
Author: Stian Skjelstad stian.skjelstad@gmail.com Signed-off-by: Stian Skjelstad stian.skjelstad@gmail.com
diff --git a/maemo/alsa-dsp.c b/maemo/alsa-dsp.c index 7e04f6a..3307384 100644 --- a/maemo/alsa-dsp.c +++ b/maemo/alsa-dsp.c @@ -135,18 +135,18 @@ static snd_pcm_sframes_t alsa_dsp_transfer(snd_pcm_ioplug_t * io, snd_pcm_alsa_dsp_t *alsa_dsp = io->private_data; DENTER(); char *buf; - int words; + int bytes, words; ssize_t result;
- words = size * alsa_dsp->bytes_per_frame; - words /= 2; - DPRINT("***** Info: words %d size %lu bpf: %d\n", words, size, - alsa_dsp->bytes_per_frame); - if (words > alsa_dsp->dsp_protocol->mmap_buffer_size) { - DERROR("Requested too much data transfer (playing only %d)\n", - alsa_dsp->dsp_protocol->mmap_buffer_size); - words = alsa_dsp->dsp_protocol->mmap_buffer_size; + bytes = size * alsa_dsp->bytes_per_frame; + DPRINT("***** Info: samples %lu * bpf %d => bytes %d\n", + size, alsa_dsp->bytes_per_frame, bytes); + if (bytes > alsa_dsp->dsp_protocol->mmap_buffer_size) { + DERROR("Requested too much data transfer (requested %d, playing only %d)\n", + bytes, alsa_dsp->dsp_protocol->mmap_buffer_size); + bytes = alsa_dsp->dsp_protocol->mmap_buffer_size; } + words = bytes / 2; if (alsa_dsp->dsp_protocol->state != STATE_PLAYING) { DPRINT("I did nothing - No start sent\n"); alsa_dsp_start(io); diff --git a/maemo/dsp-ctl.c b/maemo/dsp-ctl.c index 5bcda36..ac05942 100644 --- a/maemo/dsp-ctl.c +++ b/maemo/dsp-ctl.c @@ -93,6 +93,7 @@ static void dsp_ctl_close(snd_ctl_ext_t * ext) snd_ctl_dsp_t *dsp_ctl = ext->private_data; DENTER(); free(dsp_ctl->controls); + dsp_ctl->controls = NULL; free_control_list(&(dsp_ctl->playback_devices)); free_control_list(&(dsp_ctl->recording_devices)); // free(dsp_ctl); diff --git a/maemo/dsp-protocol.c b/maemo/dsp-protocol.c index af67251..32193d3 100644 --- a/maemo/dsp-protocol.c +++ b/maemo/dsp-protocol.c @@ -194,7 +194,7 @@ int dsp_protocol_open_node(dsp_protocol_t * dsp_protocol, const char *device) mmap((void *)0, dsp_protocol->mmap_buffer_size, PROT_READ | PROT_WRITE, MAP_SHARED, dsp_protocol->fd, 0);
- if (dsp_protocol->mmap_buffer == NULL) { + if (dsp_protocol->mmap_buffer == MAP_FAILED) { report_dsp_protocol("Cannot mmap data buffer", dsp_protocol); ret = -ENOMEM; goto unlock;