diff options
| -rw-r--r-- | fs/fcntl.c | 118 |
1 files changed, 67 insertions, 51 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c index ed4283d500a3..bbf80344c125 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -506,76 +506,92 @@ 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, |