6.6-stable review patch. If anyone has any objections, please let me know.
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From: Takashi Iwai tiwai@suse.de
commit ecfd41166b72b67d3bdeb88d224ff445f6163869 upstream.
UAC3 class segment descriptors need to be verified whether their sizes match with the declared lengths and whether they fit with the allocated buffer sizes, too. Otherwise malicious firmware may lead to the unexpected OOB accesses.
Fixes: 11785ef53228 ("ALSA: usb-audio: Initial Power Domain support") Reported-and-tested-by: Youngjun Lee yjjuny.lee@samsung.com Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20250814081245.8902-2-tiwai@suse.de Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- sound/usb/stream.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-)
--- a/sound/usb/stream.c +++ b/sound/usb/stream.c @@ -341,20 +341,28 @@ snd_pcm_chmap_elem *convert_chmap_v3(str
len = le16_to_cpu(cluster->wLength); c = 0; - p += sizeof(struct uac3_cluster_header_descriptor); + p += sizeof(*cluster); + len -= sizeof(*cluster);
- while (((p - (void *)cluster) < len) && (c < channels)) { + while (len > 0 && (c < channels)) { struct uac3_cluster_segment_descriptor *cs_desc = p; u16 cs_len; u8 cs_type;
+ if (len < sizeof(*p)) + break; cs_len = le16_to_cpu(cs_desc->wLength); + if (len < cs_len) + break; cs_type = cs_desc->bSegmentType;
if (cs_type == UAC3_CHANNEL_INFORMATION) { struct uac3_cluster_information_segment_descriptor *is = p; unsigned char map;
+ if (cs_len < sizeof(*is)) + break; + /* * TODO: this conversion is not complete, update it * after adding UAC3 values to asound.h @@ -456,6 +464,7 @@ snd_pcm_chmap_elem *convert_chmap_v3(str chmap->map[c++] = map; } p += cs_len; + len -= cs_len; }
if (channels < c) @@ -876,7 +885,7 @@ snd_usb_get_audioformat_uac3(struct snd_ u64 badd_formats = 0; unsigned int num_channels; struct audioformat *fp; - u16 cluster_id, wLength; + u16 cluster_id, wLength, cluster_wLength; int clock = 0; int err;
@@ -1003,6 +1012,16 @@ snd_usb_get_audioformat_uac3(struct snd_ iface_no, altno); kfree(cluster); return ERR_PTR(-EIO); + } + + cluster_wLength = le16_to_cpu(cluster->wLength); + if (cluster_wLength < sizeof(*cluster) || + cluster_wLength > wLength) { + dev_err(&dev->dev, + "%u:%d : invalid Cluster Descriptor size\n", + iface_no, altno); + kfree(cluster); + return ERR_PTR(-EIO); }
num_channels = cluster->bNrChannels;