fgets: avoid arithmetic overflow when n==INT_MIN is passed

[musl] / src / unistd / faccessat.c

diff --git a/src/unistd/faccessat.c b/src/unistd/faccessat.c
index 821e13f..557503e 100644 (file)
--- a/src/unistd/faccessat.c
+++ b/src/unistd/faccessat.c
@@ -1,5 +1,6 @@
 #include <unistd.h>
 #include <fcntl.h>
+#include <sys/wait.h>
 #include "syscall.h"
 #include "pthread_impl.h"
 
@@ -24,14 +25,21 @@ static int checker(void *p)
 
 int faccessat(int fd, const char *filename, int amode, int flag)
 {
-       if (!flag || (flag==AT_EACCESS && getuid()==geteuid() && getgid()==getegid()))
-               return syscall(SYS_faccessat, fd, filename, amode, flag);
+       if (flag) {
+               int ret = __syscall(SYS_faccessat2, fd, filename, amode, flag);
+               if (ret != -ENOSYS) return __syscall_ret(ret);
+       }
 
-       if (flag != AT_EACCESS)
+       if (flag & ~AT_EACCESS)
                return __syscall_ret(-EINVAL);
 
+       if (!flag || (getuid()==geteuid() && getgid()==getegid()))
+               return syscall(SYS_faccessat, fd, filename, amode);
+
        char stack[1024];
        sigset_t set;
+       pid_t pid;
+       int status;
        int ret, p[2];
 
        if (pipe2(p, O_CLOEXEC)) return __syscall_ret(-EBUSY);
@@ -39,12 +47,13 @@ int faccessat(int fd, const char *filename, int amode, int flag)
 
        __block_all_sigs(&set);
        
-       ret = __clone(checker, stack+sizeof stack, 0, &c);
+       pid = __clone(checker, stack+sizeof stack, 0, &c);
        __syscall(SYS_close, p[1]);
 
-       if (ret<0 || __syscall(SYS_read, p[0], &ret, sizeof ret) != sizeof(ret))
+       if (pid<0 || __syscall(SYS_read, p[0], &ret, sizeof ret) != sizeof(ret))
                ret = -EBUSY;
        __syscall(SYS_close, p[0]);
+       __syscall(SYS_wait4, pid, &status, __WCLONE, 0);
 
        __restore_sigs(&set);