system/serenity
system/serenity
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Add some basic address validation to syscalls.

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This is extremely ineffcient, but it doesn't really matter yet.
This commit is contained in:
Andreas Kling 2018-10-27 00:25:08 +02:00
parent 2716a9e2d7
commit 509e5f9952
2 changed files with 43 additions and 1 deletions
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17
Kernel/Task.cpp
View file

@ -182,8 +182,16 @@ int Task::sys$munmap(void* addr, size_t size)
return 0;
}
#define VALIDATE_USER_BUFFER(b, s) \
do { \
LinearAddress laddr((dword)(b)); \
if (!isValidAddressForUser(laddr) || !isValidAddressForUser(laddr.offset((s) - 1))) \
return -EFAULT; \
} while(0)
int Task::sys$gethostname(char* buffer, size_t size)
{
VALIDATE_USER_BUFFER(buffer, size);
auto hostname = getHostname();
if (size < (hostname.length() + 1))
return -ENAMETOOLONG;
@ -670,6 +678,7 @@ FileHandle* Task::fileHandleIfExists(int fd)
ssize_t Task::sys$get_dir_entries(int fd, void* buffer, size_t size)
{
VALIDATE_USER_BUFFER(buffer, size);
auto* handle = fileHandleIfExists(fd);
if (!handle)
return -1;
@ -686,7 +695,7 @@ int Task::sys$seek(int fd, int offset)
ssize_t Task::sys$read(int fd, void* outbuf, size_t nread)
{
Task::checkSanity("Task::sys$read");
VALIDATE_USER_BUFFER(outbuf, nread);
#ifdef DEBUG_IO
kprintf("Task::sys$read: called(%d, %p, %u)\n", fd, outbuf, nread);
#endif
@ -726,6 +735,7 @@ int Task::sys$close(int fd)
int Task::sys$lstat(const char* path, void* statbuf)
{
VALIDATE_USER_BUFFER(statbuf, sizeof(stat));
auto handle = VirtualFileSystem::the().open(move(path), m_cwd.ptr());
if (!handle)
return -1;
@ -735,6 +745,7 @@ int Task::sys$lstat(const char* path, void* statbuf)
int Task::sys$chdir(const char* path)
{
VALIDATE_USER_BUFFER(path, strlen(path));
auto handle = VirtualFileSystem::the().open(path, m_cwd.ptr());
if (!handle)
return -ENOENT; // FIXME: More detailed error.
@ -748,6 +759,7 @@ int Task::sys$chdir(const char* path)
int Task::sys$getcwd(char* buffer, size_t size)
{
// FIXME: Implement!
VALIDATE_USER_BUFFER(buffer, size);
return -ENOTIMPL;
}
@ -756,6 +768,7 @@ int Task::sys$open(const char* path, size_t pathLength)
#ifdef DEBUG_IO
kprintf("Task::sys$open(): PID=%u, path=%s {%u}\n", m_pid, path, pathLength);
#endif
VALIDATE_USER_BUFFER(path, pathLength);
if (m_fileHandles.size() >= m_maxFileHandles)
return -EMFILE;
auto handle = VirtualFileSystem::the().open(String(path, pathLength), m_cwd.ptr());
@ -769,6 +782,7 @@ int Task::sys$open(const char* path, size_t pathLength)
int Task::sys$uname(utsname* buf)
{
VALIDATE_USER_BUFFER(buf, sizeof(utsname));
strcpy(buf->sysname, "Serenity");
strcpy(buf->release, "1.0-dev");
strcpy(buf->version, "FIXME");
@ -807,6 +821,7 @@ int Task::sys$sleep(unsigned seconds)
int Task::sys$gettimeofday(timeval* tv)
{
VALIDATE_USER_BUFFER(tv, sizeof(tv));
InterruptDisabler disabler;
auto now = RTC::now();
tv->tv_sec = now;

27
Kernel/types.h
View file

@ -41,6 +41,33 @@ struct utsname {
char machine[UTSNAME_ENTRY_LEN];
};
typedef dword ino_t;
typedef signed_dword off_t;
typedef dword dev_t;
typedef dword mode_t;
typedef dword nlink_t;
typedef dword blksize_t;
typedef dword blkcnt_t;
typedef dword time_t;
typedef dword suseconds_t;
struct stat {
dev_t st_dev; /* ID of device containing file */
ino_t st_ino; /* inode number */
mode_t st_mode; /* protection */
nlink_t st_nlink; /* number of hard links */
uid_t st_uid; /* user ID of owner */
gid_t st_gid; /* group ID of owner */
dev_t st_rdev; /* device ID (if special file) */
off_t st_size; /* total size, in bytes */
blksize_t st_blksize; /* blocksize for file system I/O */
blkcnt_t st_blocks; /* number of 512B blocks allocated */
time_t st_atime; /* time of last access */
time_t st_mtime; /* time of last modification */
time_t st_ctime; /* time of last status change */
};
struct FarPtr {
DWORD offset { 0 };
WORD selector { 0 };