]> git.kernelconcepts.de Git - karo-tx-linux.git/blobdiff - fs/fcntl.c
Merge branch 'misc.alpha' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[karo-tx-linux.git] / fs / fcntl.c
index ed051f825badcb5e64a21ed108048483bbd49efa..b6bd89628025d84dc312e15613cd2e30f57b20d6 100644 (file)
@@ -109,20 +109,34 @@ void __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
 }
 EXPORT_SYMBOL(__f_setown);
 
-void f_setown(struct file *filp, unsigned long arg, int force)
+int f_setown(struct file *filp, unsigned long arg, int force)
 {
        enum pid_type type;
-       struct pid *pid;
-       int who = arg;
+       struct pid *pid = NULL;
+       int who = arg, ret = 0;
+
        type = PIDTYPE_PID;
        if (who < 0) {
+               /* avoid overflow below */
+               if (who == INT_MIN)
+                       return -EINVAL;
+
                type = PIDTYPE_PGID;
                who = -who;
        }
+
        rcu_read_lock();
-       pid = find_vpid(who);
-       __f_setown(filp, pid, type, force);
+       if (who) {
+               pid = find_vpid(who);
+               if (!pid)
+                       ret = -ESRCH;
+       }
+
+       if (!ret)
+               __f_setown(filp, pid, type, force);
        rcu_read_unlock();
+
+       return ret;
 }
 EXPORT_SYMBOL(f_setown);
 
@@ -307,6 +321,8 @@ static long fcntl_rw_hint(struct file *file, unsigned int cmd,
 static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
                struct file *filp)
 {
+       void __user *argp = (void __user *)arg;
+       struct flock flock;
        long err = -EINVAL;
 
        switch (cmd) {
@@ -334,7 +350,11 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
        case F_OFD_GETLK:
 #endif
        case F_GETLK:
-               err = fcntl_getlk(filp, cmd, (struct flock __user *) arg);
+               if (copy_from_user(&flock, argp, sizeof(flock)))
+                       return -EFAULT;
+               err = fcntl_getlk(filp, cmd, &flock);
+               if (!err && copy_to_user(argp, &flock, sizeof(flock)))
+                       return -EFAULT;
                break;
 #if BITS_PER_LONG != 32
        /* 32-bit arches must use fcntl64() */
@@ -344,7 +364,9 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
                /* Fallthrough */
        case F_SETLK:
        case F_SETLKW:
-               err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg);
+               if (copy_from_user(&flock, argp, sizeof(flock)))
+                       return -EFAULT;
+               err = fcntl_setlk(fd, filp, cmd, &flock);
                break;
        case F_GETOWN:
                /*
@@ -358,8 +380,7 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
                force_successful_syscall_return();
                break;
        case F_SETOWN:
-               f_setown(filp, arg, 1);
-               err = 0;
+               err = f_setown(filp, arg, 1);
                break;
        case F_GETOWN_EX:
                err = f_getown_ex(filp, arg);
@@ -450,7 +471,9 @@ out:
 SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
                unsigned long, arg)
 {      
+       void __user *argp = (void __user *)arg;
        struct fd f = fdget_raw(fd);
+       struct flock64 flock;
        long err = -EBADF;
 
        if (!f.file)
@@ -468,14 +491,21 @@ SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
        switch (cmd) {
        case F_GETLK64:
        case F_OFD_GETLK:
-               err = fcntl_getlk64(f.file, cmd, (struct flock64 __user *) arg);
+               err = -EFAULT;
+               if (copy_from_user(&flock, argp, sizeof(flock)))
+                       break;
+               err = fcntl_getlk64(f.file, cmd, &flock);
+               if (!err && copy_to_user(argp, &flock, sizeof(flock)))
+                       err = -EFAULT;
                break;
        case F_SETLK64:
        case F_SETLKW64:
        case F_OFD_SETLK:
        case F_OFD_SETLKW:
-               err = fcntl_setlk64(fd, f.file, cmd,
-                               (struct flock64 __user *) arg);
+               err = -EFAULT;
+               if (copy_from_user(&flock, argp, sizeof(flock)))
+                       break;
+               err = fcntl_setlk64(fd, f.file, cmd, &flock);
                break;
        default:
                err = do_fcntl(fd, cmd, arg, f.file);
@@ -489,57 +519,56 @@ out:
 #endif
 
 #ifdef CONFIG_COMPAT
+/* careful - don't use anywhere else */
+#define copy_flock_fields(from, to)            \
+       (to).l_type = (from).l_type;            \
+       (to).l_whence = (from).l_whence;        \
+       (to).l_start = (from).l_start;          \
+       (to).l_len = (from).l_len;              \
+       (to).l_pid = (from).l_pid;
+
 static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
 {
-       if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
-           __get_user(kfl->l_type, &ufl->l_type) ||
-           __get_user(kfl->l_whence, &ufl->l_whence) ||
-           __get_user(kfl->l_start, &ufl->l_start) ||
-           __get_user(kfl->l_len, &ufl->l_len) ||
-           __get_user(kfl->l_pid, &ufl->l_pid))
+       struct compat_flock fl;
+
+       if (copy_from_user(&fl, ufl, sizeof(struct compat_flock)))
                return -EFAULT;
+       copy_flock_fields(*kfl, fl);
        return 0;
 }
 
-static int put_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
+static int get_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
 {
-       if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
-           __put_user(kfl->l_type, &ufl->l_type) ||
-           __put_user(kfl->l_whence, &ufl->l_whence) ||
-           __put_user(kfl->l_start, &ufl->l_start) ||
-           __put_user(kfl->l_len, &ufl->l_len) ||
-           __put_user(kfl->l_pid, &ufl->l_pid))
+       struct compat_flock64 fl;
+
+       if (copy_from_user(&fl, ufl, sizeof(struct compat_flock64)))
                return -EFAULT;
+       copy_flock_fields(*kfl, fl);
        return 0;
 }
 
-#ifndef HAVE_ARCH_GET_COMPAT_FLOCK64
-static int get_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
+static int put_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
 {
-       if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
-           __get_user(kfl->l_type, &ufl->l_type) ||
-           __get_user(kfl->l_whence, &ufl->l_whence) ||
-           __get_user(kfl->l_start, &ufl->l_start) ||
-           __get_user(kfl->l_len, &ufl->l_len) ||
-           __get_user(kfl->l_pid, &ufl->l_pid))
+       struct compat_flock fl;
+
+       memset(&fl, 0, sizeof(struct compat_flock));
+       copy_flock_fields(fl, *kfl);
+       if (copy_to_user(ufl, &fl, sizeof(struct compat_flock)))
                return -EFAULT;
        return 0;
 }
-#endif
 
-#ifndef HAVE_ARCH_PUT_COMPAT_FLOCK64
 static int put_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
 {
-       if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
-           __put_user(kfl->l_type, &ufl->l_type) ||
-           __put_user(kfl->l_whence, &ufl->l_whence) ||
-           __put_user(kfl->l_start, &ufl->l_start) ||
-           __put_user(kfl->l_len, &ufl->l_len) ||
-           __put_user(kfl->l_pid, &ufl->l_pid))
+       struct compat_flock64 fl;
+
+       memset(&fl, 0, sizeof(struct compat_flock64));
+       copy_flock_fields(fl, *kfl);
+       if (copy_to_user(ufl, &fl, sizeof(struct compat_flock64)))
                return -EFAULT;
        return 0;
 }
-#endif
+#undef copy_flock_fields
 
 static unsigned int
 convert_fcntl_cmd(unsigned int cmd)
@@ -556,76 +585,92 @@ convert_fcntl_cmd(unsigned int cmd)
        return cmd;
 }
 
+/*
+ * GETLK was successful and we need to return the data, but it needs to fit in
+ * the compat structure.
+ * l_start shouldn't be too big, unless the original start + end is greater than
+ * COMPAT_OFF_T_MAX, in which case the app was asking for trouble, so we return
+ * -EOVERFLOW in that case.  l_len could be too big, in which case we just
+ * truncate it, and only allow the app to see that part of the conflicting lock
+ * that might make sense to it anyway
+ */
+static int fixup_compat_flock(struct flock *flock)
+{
+       if (flock->l_start > COMPAT_OFF_T_MAX)
+               return -EOVERFLOW;
+       if (flock->l_len > COMPAT_OFF_T_MAX)
+               flock->l_len = COMPAT_OFF_T_MAX;
+       return 0;
+}
+
 COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
                       compat_ulong_t, arg)
 {
-       mm_segment_t old_fs;
-       struct flock f;
-       long ret;
-       unsigned int conv_cmd;
+       struct fd f = fdget_raw(fd);
+       struct flock flock;
+       long err = -EBADF;
+
+       if (!f.file)
+               return err;
+
+       if (unlikely(f.file->f_mode & FMODE_PATH)) {
+               if (!check_fcntl_cmd(cmd))
+                       goto out_put;
+       }
+
+       err = security_file_fcntl(f.file, cmd, arg);
+       if (err)
+               goto out_put;
 
        switch (cmd) {
        case F_GETLK:
+               err = get_compat_flock(&flock, compat_ptr(arg));
+               if (err)
+                       break;
+               err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock);
+               if (err)
+                       break;
+               err = fixup_compat_flock(&flock);
+               if (err)
+                       return err;
+               err = put_compat_flock(&flock, compat_ptr(arg));
+               break;
+       case F_GETLK64:
+       case F_OFD_GETLK:
+               err = get_compat_flock64(&flock, compat_ptr(arg));
+               if (err)
+                       break;
+               err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock);
+               if (err)
+                       break;
+               err = fixup_compat_flock(&flock);
+               if (err)
+                       return err;
+               err = put_compat_flock64(&flock, compat_ptr(arg));
+               break;
        case F_SETLK:
        case F_SETLKW:
-               ret = get_compat_flock(&f, compat_ptr(arg));
-               if (ret != 0)
+               err = get_compat_flock(&flock, compat_ptr(arg));
+               if (err)
                        break;
-               old_fs = get_fs();
-               set_fs(KERNEL_DS);
-               ret = sys_fcntl(fd, cmd, (unsigned long)&f);
-               set_fs(old_fs);
-               if (cmd == F_GETLK && ret == 0) {
-                       /* GETLK was successful and we need to return the data...
-                        * but it needs to fit in the compat structure.
-                        * l_start shouldn't be too big, unless the original
-                        * start + end is greater than COMPAT_OFF_T_MAX, in which
-                        * case the app was asking for trouble, so we return
-                        * -EOVERFLOW in that case.
-                        * l_len could be too big, in which case we just truncate it,
-                        * and only allow the app to see that part of the conflicting
-                        * lock that might make sense to it anyway
-                        */
-
-                       if (f.l_start > COMPAT_OFF_T_MAX)
-                               ret = -EOVERFLOW;
-                       if (f.l_len > COMPAT_OFF_T_MAX)
-                               f.l_len = COMPAT_OFF_T_MAX;
-                       if (ret == 0)
-                               ret = put_compat_flock(&f, compat_ptr(arg));
-               }
+               err = fcntl_setlk(fd, f.file, convert_fcntl_cmd(cmd), &flock);
                break;
-
-       case F_GETLK64:
        case F_SETLK64:
        case F_SETLKW64:
-       case F_OFD_GETLK:
        case F_OFD_SETLK:
        case F_OFD_SETLKW:
-               ret = get_compat_flock64(&f, compat_ptr(arg));
-               if (ret != 0)
+               err = get_compat_flock64(&flock, compat_ptr(arg));
+               if (err)
                        break;
-               old_fs = get_fs();
-               set_fs(KERNEL_DS);
-               conv_cmd = convert_fcntl_cmd(cmd);
-               ret = sys_fcntl(fd, conv_cmd, (unsigned long)&f);
-               set_fs(old_fs);
-               if ((conv_cmd == F_GETLK || conv_cmd == F_OFD_GETLK) && ret == 0) {
-                       /* need to return lock information - see above for commentary */
-                       if (f.l_start > COMPAT_LOFF_T_MAX)
-                               ret = -EOVERFLOW;
-                       if (f.l_len > COMPAT_LOFF_T_MAX)
-                               f.l_len = COMPAT_LOFF_T_MAX;
-                       if (ret == 0)
-                               ret = put_compat_flock64(&f, compat_ptr(arg));
-               }
+               err = fcntl_setlk(fd, f.file, convert_fcntl_cmd(cmd), &flock);
                break;
-
        default:
-               ret = sys_fcntl(fd, cmd, arg);
+               err = do_fcntl(fd, cmd, arg, f.file);
                break;
        }
-       return ret;
+out_put:
+       fdput(f);
+       return err;
 }
 
 COMPAT_SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd,