BUG/MEDIUM: signal: signal handler does not properly check for signal bounds
sig is checked for < 0 or > MAX_SIGNAL, but the signal array is
MAX_SIGNAL in size. At the moment, MAX_SIGNAL is 256. If a system supports
more than MAX_SIGNAL signals, then sending signal MAX_SIGNAL to the process
will corrupt one integer in its memory and might also crash the process.
This bug is also present in 1.4 and 1.3, and the fix must be backported.
Reported-by: Dinko Korunic <dkorunic@reflected.net>
diff --git a/src/signal.c b/src/signal.c
index fb6980b..e9301ed 100644
--- a/src/signal.c
+++ b/src/signal.c
@@ -37,7 +37,7 @@
*/
void signal_handler(int sig)
{
- if (sig < 0 || sig > MAX_SIGNAL) {
+ if (sig < 0 || sig >= MAX_SIGNAL) {
/* unhandled signal */
signal(sig, SIG_IGN);
qfprintf(stderr, "Received unhandled signal %d. Signal has been disabled.\n", sig);
@@ -142,7 +142,7 @@
{
struct sig_handler *sh;
- if (sig < 0 || sig > MAX_SIGNAL)
+ if (sig < 0 || sig >= MAX_SIGNAL)
return NULL;
if (sig)
@@ -174,7 +174,7 @@
{
struct sig_handler *sh;
- if (sig < 0 || sig > MAX_SIGNAL)
+ if (sig < 0 || sig >= MAX_SIGNAL)
return NULL;
if (sig)
@@ -213,7 +213,7 @@
{
struct sig_handler *sh, *shb;
- if (sig < 0 || sig > MAX_SIGNAL)
+ if (sig < 0 || sig >= MAX_SIGNAL)
return;
if (!target)