> On Nov 7, 2021, at 5:48 AM, Richard Henderson <richard.hender...@linaro.org>
> wrote:
>
> We currently use a flexible array member for target_dirent,
> but use incorrectly fixed length arrays for target_dirent64,
> linux_dirent and linux_dirent64.
>
> This requires that we adjust the definition of the VFAT READDIR
> ioctls which hard-code the 256 namelen size into the ioctl constant.
>
> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
> ---
> linux-user/syscall_defs.h | 6 +++---
> linux-user/syscall.c | 6 ++++--
> 2 files changed, 7 insertions(+), 5 deletions(-)
Reviewed by: Warner Losh <i...@bsdimp.com>
> diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
> index a5ce487dcc..98b09ee6d6 100644
> --- a/linux-user/syscall_defs.h
> +++ b/linux-user/syscall_defs.h
> @@ -441,7 +441,7 @@ struct target_dirent64 {
> int64_t d_off;
> unsigned short d_reclen;
> unsigned char d_type;
> - char d_name[256];
> + char d_name[];
> };
>
>
> @@ -2714,7 +2714,7 @@ struct linux_dirent {
> long d_ino;
> unsigned long d_off;
> unsigned short d_reclen;
> - char d_name[256]; /* We must not include limits.h! */
> + char d_name[];
> };
>
> struct linux_dirent64 {
> @@ -2722,7 +2722,7 @@ struct linux_dirent64 {
> int64_t d_off;
> unsigned short d_reclen;
> unsigned char d_type;
> - char d_name[256];
> + char d_name[];
> };
>
> struct target_mq_attr {
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index a2f605dec4..499415ad81 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -197,8 +197,10 @@
> //#define DEBUG_ERESTARTSYS
>
> //#include <linux/msdos_fs.h>
> -#define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct
> linux_dirent [2])
> -#define VFAT_IOCTL_READDIR_SHORT _IOR('r', 2, struct
> linux_dirent [2])
> +#define VFAT_IOCTL_READDIR_BOTH \
> + _IOC(_IOC_READ, 'r', 1, (sizeof(struct linux_dirent) + 256) * 2)
> +#define VFAT_IOCTL_READDIR_SHORT \
> + _IOC(_IOC_READ, 'r', 2, (sizeof(struct linux_dirent) + 256) * 2)
>
> #undef _syscall0
> #undef _syscall1
> --
> 2.25.1
>
>
