When calling snd_use_case_geti(uc_mgr, "_devstatus", &lvalue) the code ends up calling device_status(uc_mgr, NULL), which result in a crash in strcmp(dev->name, NULL), when there are enabled devices.
This happens because snd_use_case_geti() allows a "_devstatus" identifier even if it's only supposed to allow the form "_devstatus/{device}".
So check that the device name is not null.
The same issue occurs with "_modstatus", this change fixes that as well.
Signed-off-by: Antonio Ospite ao2@ao2.it ---
Hi,
the bug can be reproduced with a command like this:
# alsaucm -n -b - <<EOM open bytcr-rt5640 reset set _verb HiFi set _device Speaker geti _devstatus EOM Segmentation fault
I decided to add the check once per command instead of doing this:
@@ -1525,7 +1525,8 @@ int snd_use_case_geti(snd_use_case_mgr_t *uc_mgr, goto __end; } } else { - str = NULL; + err = -EINVAL; + goto __end; }
because the function body seems to be prepared to accept other forms of identifiers, possibly even without a "prefix/suffix" structure.
Ciao ciao, Antonio
P.S. the source code in src/ucm has a mixed indentation style of TABs and spaces, would you accept a patch to uniform the style?
src/ucm/main.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/src/ucm/main.c b/src/ucm/main.c index 24d9510..d5e418e 100644 --- a/src/ucm/main.c +++ b/src/ucm/main.c @@ -1528,12 +1528,20 @@ int snd_use_case_geti(snd_use_case_mgr_t *uc_mgr, str = NULL; } if (check_identifier(identifier, "_devstatus")) { + if(!str) { + err = -EINVAL; + goto __end; + } err = device_status(uc_mgr, str); if (err >= 0) { *value = err; err = 0; } } else if (check_identifier(identifier, "_modstatus")) { + if(!str) { + err = -EINVAL; + goto __end; + } err = modifier_status(uc_mgr, str); if (err >= 0) { *value = err;