prevent CNAME/PTR parsing from reading data past the response end

[musl] / src / conf / sysconf.c

diff --git a/src/conf/sysconf.c b/src/conf/sysconf.c
index 45ef1c1..60d3e74 100644 (file)
--- a/src/conf/sysconf.c
+++ b/src/conf/sysconf.c
@@ -4,6 +4,7 @@
 #include <sys/resource.h>
 #include <signal.h>
 #include <sys/sysinfo.h>
+#include <sys/auxv.h>
 #include "syscall.h"
 #include "libc.h"
 
@@ -19,6 +20,8 @@
 #define JT_AVPHYS_PAGES JT(9)
 #define JT_ZERO JT(10)
 #define JT_DELAYTIMER_MAX JT(11)
+#define JT_MINSIGSTKSZ JT(12)
+#define JT_SIGSTKSZ JT(13)
 
 #define RLIM(x) (-32768|(RLIMIT_ ## x))
 
@@ -165,6 +168,9 @@ long sysconf(int name)
                [_SC_XOPEN_STREAMS] = JT_ZERO,
                [_SC_THREAD_ROBUST_PRIO_INHERIT] = -1,
                [_SC_THREAD_ROBUST_PRIO_PROTECT] = -1,
+
+               [_SC_MINSIGSTKSZ] = JT_MINSIGSTKSZ,
+               [_SC_SIGSTKSZ] = JT_SIGSTKSZ,
        };
 
        if (name >= sizeof(values)/sizeof(values[0]) || !values[name]) {
@@ -204,7 +210,6 @@ long sysconf(int name)
        case JT_PHYS_PAGES & 255:
        case JT_AVPHYS_PAGES & 255: ;
                unsigned long long mem;
-               int __lsysinfo(struct sysinfo *);
                struct sysinfo si;
                __lsysinfo(&si);
                if (!si.mem_unit) si.mem_unit = 1;
@@ -213,6 +218,13 @@ long sysconf(int name)
                mem *= si.mem_unit;
                mem /= PAGE_SIZE;
                return (mem > LONG_MAX) ? LONG_MAX : mem;
+       case JT_MINSIGSTKSZ & 255:
+       case JT_SIGSTKSZ & 255: ;
+               long val = __getauxval(AT_MINSIGSTKSZ);
+               if (val < MINSIGSTKSZ) val = MINSIGSTKSZ;
+               if (values[name] == JT_SIGSTKSZ)
+                       val += SIGSTKSZ - MINSIGSTKSZ;
+               return val;
        case JT_ZERO & 255:
                return 0;
        }