Home Home > GIT Browse > SLE15-AZURE
summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorTakashi Iwai <tiwai@suse.de>2019-08-16 20:39:29 +0200
committerTakashi Iwai <tiwai@suse.de>2019-08-16 20:39:34 +0200
commitf98d83afebcd18db4565b72fcd807a0dc1fbda44 (patch)
treebe2128f0a6f7354882d89d8ba72e785040ade977
parent075ae89977e6607e954a35eb40e22e6768c737b8 (diff)
ALSA: usb-audio: Fix a stack buffer overflow bug in
check_input_term (CVE-2019-15118,bsc#1145922). suse-commit: c68760ff488d7dfab052a81067e9922a90286734
-rw-r--r--sound/usb/mixer.c28
1 files changed, 23 insertions, 5 deletions
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 930187127d3c..a1b97315a84a 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -82,6 +82,7 @@ struct mixer_build {
unsigned char *buffer;
unsigned int buflen;
DECLARE_BITMAP(unitbitmap, MAX_ID_ELEMS);
+ DECLARE_BITMAP(termbitmap, MAX_ID_ELEMS);
struct usb_audio_term oterm;
const struct usbmix_name_map *map;
const struct usbmix_selector_map *selector_map;
@@ -710,15 +711,24 @@ static int get_term_name(struct mixer_build *state, struct usb_audio_term *iterm
* parse the source unit recursively until it reaches to a terminal
* or a branched unit.
*/
-static int check_input_term(struct mixer_build *state, int id,
+static int __check_input_term(struct mixer_build *state, int id,
struct usb_audio_term *term)
{
int err;
void *p1;
+ unsigned char *hdr;
memset(term, 0, sizeof(*term));
- while ((p1 = find_audio_control_unit(state, id)) != NULL) {
- unsigned char *hdr = p1;
+ for (;;) {
+ /* a loop in the terminal chain? */
+ if (test_and_set_bit(id, state->termbitmap))
+ return -EINVAL;
+
+ p1 = find_audio_control_unit(state, id);
+ if (!p1)
+ break;
+
+ hdr = p1;
term->id = id;
switch (hdr[2]) {
case UAC_INPUT_TERMINAL:
@@ -733,7 +743,7 @@ static int check_input_term(struct mixer_build *state, int id,
/* call recursively to verify that the
* referenced clock entity is valid */
- err = check_input_term(state, d->bCSourceID, term);
+ err = __check_input_term(state, d->bCSourceID, term);
if (err < 0)
return err;
@@ -765,7 +775,7 @@ static int check_input_term(struct mixer_build *state, int id,
case UAC2_CLOCK_SELECTOR: {
struct uac_selector_unit_descriptor *d = p1;
/* call recursively to retrieve the channel info */
- err = check_input_term(state, d->baSourceID[0], term);
+ err = __check_input_term(state, d->baSourceID[0], term);
if (err < 0)
return err;
term->type = d->bDescriptorSubtype << 16; /* virtual type */
@@ -812,6 +822,14 @@ static int check_input_term(struct mixer_build *state, int id,
return -ENODEV;
}
+static int check_input_term(struct mixer_build *state, int id,
+ struct usb_audio_term *term)
+{
+ memset(term, 0, sizeof(*term));
+ memset(state->termbitmap, 0, sizeof(state->termbitmap));
+ return __check_input_term(state, id, term);
+}
+
/*
* Feature Unit
*/