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Staging: sst: more dereferencing user pointers
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This is another patch about making a copy of the data into kernel space
before using it.  It is easy to trigger a kernel oops in the original
code.  If you passed a NULL to SNDRV_SST_SET_TARGET_DEVICE then it
called BUG_ON().  And SNDRV_SST_DRIVER_INFO would let you write the
information to arbitrary memory locations which is a security violation.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Dan Carpenter authored and Greg Kroah-Hartman committed Nov 9, 2010
1 parent 3b97eed commit bc704e3
Showing 1 changed file with 46 additions and 29 deletions.
75 changes: 46 additions & 29 deletions drivers/staging/intel_sst/intel_sst_app_interface.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -838,25 +838,33 @@ long intel_sst_ioctl(struct file *file_ptr, unsigned int cmd, unsigned long arg)
break;

case _IOC_NR(SNDRV_SST_STREAM_SET_PARAMS): {
struct snd_sst_params *str_param = (struct snd_sst_params *)arg;
struct snd_sst_params str_param;

pr_debug("sst: IOCTL_SET_PARAMS recieved!\n");
if (minor != STREAM_MODULE) {
retval = -EBADRQC;
break;
}

if (copy_from_user(&str_param, (void __user *)arg,
sizeof(str_param))) {
retval = -EFAULT;
break;
}

if (!str_id) {

retval = sst_get_stream(str_param);
retval = sst_get_stream(&str_param);
if (retval > 0) {
struct stream_info *str_info;
char __user *dest;

sst_drv_ctx->stream_cnt++;
data->str_id = retval;
str_info = &sst_drv_ctx->streams[retval];
str_info->src = SST_DRV;
retval = copy_to_user(&str_param->stream_id,
&retval, sizeof(__u32));
dest = (char *)arg + offsetof(struct snd_sst_params, stream_id);
retval = copy_to_user(dest, &retval, sizeof(__u32));
if (retval)
retval = -EFAULT;
} else {
Expand All @@ -866,16 +874,14 @@ long intel_sst_ioctl(struct file *file_ptr, unsigned int cmd, unsigned long arg)
} else {
pr_debug("sst: SET_STREAM_PARAMS recieved!\n");
/* allocated set params only */
retval = sst_set_stream_param(str_id, str_param);
retval = sst_set_stream_param(str_id, &str_param);
/* Block the call for reply */
if (!retval) {
int sfreq = 0, word_size = 0, num_channel = 0;
sfreq = str_param->sparams.uc.pcm_params.sfreq;
word_size = str_param->sparams.
uc.pcm_params.pcm_wd_sz;
num_channel = str_param->
sparams.uc.pcm_params.num_chan;
if (str_param->ops == STREAM_OPS_CAPTURE) {
sfreq = str_param.sparams.uc.pcm_params.sfreq;
word_size = str_param.sparams.uc.pcm_params.pcm_wd_sz;
num_channel = str_param.sparams.uc.pcm_params.num_chan;
if (str_param.ops == STREAM_OPS_CAPTURE) {
sst_drv_ctx->scard_ops->\
set_pcm_audio_params(sfreq,
word_size, num_channel);
Expand Down Expand Up @@ -976,16 +982,22 @@ long intel_sst_ioctl(struct file *file_ptr, unsigned int cmd, unsigned long arg)
}

case _IOC_NR(SNDRV_SST_MMAP_PLAY):
case _IOC_NR(SNDRV_SST_MMAP_CAPTURE):
case _IOC_NR(SNDRV_SST_MMAP_CAPTURE): {
struct snd_sst_mmap_buffs mmap_buf;

pr_debug("sst: SNDRV_SST_MMAP_PLAY/CAPTURE recieved!\n");
if (minor != STREAM_MODULE) {
retval = -EBADRQC;
break;
}
retval = intel_sst_mmap_play_capture(str_id,
(struct snd_sst_mmap_buffs *)arg);
if (copy_from_user(&mmap_buf, (void __user *)arg,
sizeof(mmap_buf))) {
retval = -EFAULT;
break;
}
retval = intel_sst_mmap_play_capture(str_id, &mmap_buf);
break;

}
case _IOC_NR(SNDRV_SST_STREAM_DROP):
pr_debug("sst: SNDRV_SST_IOCTL_DROP recieved!\n");
if (minor != STREAM_MODULE) {
Expand All @@ -996,7 +1008,6 @@ long intel_sst_ioctl(struct file *file_ptr, unsigned int cmd, unsigned long arg)
break;

case _IOC_NR(SNDRV_SST_STREAM_GET_TSTAMP): {
unsigned long long *ms = (unsigned long long *)arg;
struct snd_sst_tstamp tstamp = {0};
unsigned long long time, freq, mod;

Expand All @@ -1013,7 +1024,8 @@ long intel_sst_ioctl(struct file *file_ptr, unsigned int cmd, unsigned long arg)
freq = (unsigned long long) tstamp.sampling_frequency;
time = time * 1000; /* converting it to ms */
mod = do_div(time, freq);
if (copy_to_user(ms, &time, sizeof(*ms)))
if (copy_to_user((void __user *)arg, &time,
sizeof(unsigned long long)))
retval = -EFAULT;
break;
}
Expand Down Expand Up @@ -1058,32 +1070,37 @@ long intel_sst_ioctl(struct file *file_ptr, unsigned int cmd, unsigned long arg)
}

case _IOC_NR(SNDRV_SST_SET_TARGET_DEVICE): {
struct snd_sst_target_device *target_device;
struct snd_sst_target_device target_device;

pr_debug("sst: SET_TARGET_DEVICE recieved!\n");
target_device = (struct snd_sst_target_device *)arg;
BUG_ON(!target_device);
if (copy_from_user(&target_device, (void __user *)arg,
sizeof(target_device))) {
retval = -EFAULT;
break;
}
if (minor != AM_MODULE) {
retval = -EBADRQC;
break;
}
retval = sst_target_device_select(target_device);
retval = sst_target_device_select(&target_device);
break;
}

case _IOC_NR(SNDRV_SST_DRIVER_INFO): {
struct snd_sst_driver_info *info =
(struct snd_sst_driver_info *)arg;
struct snd_sst_driver_info info;

pr_debug("sst: SNDRV_SST_DRIVER_INFO recived\n");
info->version = SST_VERSION_NUM;
info.version = SST_VERSION_NUM;
/* hard coding, shud get sumhow later */
info->active_pcm_streams = sst_drv_ctx->stream_cnt -
info.active_pcm_streams = sst_drv_ctx->stream_cnt -
sst_drv_ctx->encoded_cnt;
info->active_enc_streams = sst_drv_ctx->encoded_cnt;
info->max_pcm_streams = MAX_ACTIVE_STREAM - MAX_ENC_STREAM;
info->max_enc_streams = MAX_ENC_STREAM;
info->buf_per_stream = sst_drv_ctx->mmap_len;
info.active_enc_streams = sst_drv_ctx->encoded_cnt;
info.max_pcm_streams = MAX_ACTIVE_STREAM - MAX_ENC_STREAM;
info.max_enc_streams = MAX_ENC_STREAM;
info.buf_per_stream = sst_drv_ctx->mmap_len;
if (copy_to_user((void __user *)arg, &info,
sizeof(info)))
retval = -EFAULT;
break;
}

Expand Down

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