From 53d3b6b0a70802bad58ef6c2ec034aa4e8ebf3e6 Mon Sep 17 00:00:00 2001 From: Andreas Kling Date: Mon, 6 Jan 2020 10:51:50 +0100 Subject: [PATCH] LibC: Make the syscall wrappers for stat/lstat/chdir return EFAULT If we pass a null path to these syscall wrappers, just return EFAULT directly from the wrapper instead of segfaulting by calling strlen(). This is a compromise, since we now have to pass the path length to the kernel, so we can't rely on the kernel to tell us that the path is at a bad memory address. --- Libraries/LibC/unistd.cpp | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/Libraries/LibC/unistd.cpp b/Libraries/LibC/unistd.cpp index 8c0f093f3f..70cd0f7e8e 100644 --- a/Libraries/LibC/unistd.cpp +++ b/Libraries/LibC/unistd.cpp @@ -227,12 +227,20 @@ pid_t waitpid(pid_t waitee, int* wstatus, int options) int lstat(const char* path, struct stat* statbuf) { + if (!path) { + errno = EFAULT; + return -1; + } int rc = syscall(SC_lstat, path, strlen(path), statbuf); __RETURN_WITH_ERRNO(rc, rc, -1); } int stat(const char* path, struct stat* statbuf) { + if (!path) { + errno = EFAULT; + return -1; + } int rc = syscall(SC_stat, path, strlen(path), statbuf); __RETURN_WITH_ERRNO(rc, rc, -1); } @@ -245,6 +253,10 @@ int fstat(int fd, struct stat* statbuf) int chdir(const char* path) { + if (!path) { + errno = EFAULT; + return -1; + } int rc = syscall(SC_chdir, path, strlen(path)); __RETURN_WITH_ERRNO(rc, rc, -1); }