[poky] [PATCH 1/1] Filter out erroneous POSIX ACLs

[Burton, Ross]

Hi Anton,

Thanks for the patch, but this should go to the yocto@ list, not poky at .

Also please ensure that the subject line has [pseudo] in so that Peter
notices it!

Ross

On 24 February 2017 at 09:20, <anton at advancedtelematic.com> wrote:

> From: Anton Gerasimov <anton at advancedtelematic.com>
>
> The difference between what we see in pseudo and what happens without
> pseudo can be seen by typing:
>
>     mkdir setfattr-test
>     setfattr -n system.posix_acl_default -v 0x02000000 setfattr-test
>     getfattr -n system.posix_acl_default setfattr-test
>
> Under some kernel configurations this difference leads to annoying
> errors, e.g. directories copied with 'cp -a' get broken in a fancy way.
>
> Signed-off-by: Anton Gerasimov <anton at advancedtelematic.com>
> ---
>  ports/linux/xattr/pseudo_wrappers.c | 23 +++++++++++++++++++++--
>  1 file changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/ports/linux/xattr/pseudo_wrappers.c
> b/ports/linux/xattr/pseudo_wrappers.c
> index 46bc053..31a6baf 100644
> --- a/ports/linux/xattr/pseudo_wrappers.c
> +++ b/ports/linux/xattr/pseudo_wrappers.c
> @@ -64,7 +64,7 @@ posix_permissions(const acl_header *header, int entries,
> int *extra, int *mode)
>         if (le32(header->version) != 2) {
>                 pseudo_diag("Fatal: ACL support no available for header
> version %d.\n",
>                         le32(header->version));
> -               return 1;
> +               return -1;
>         }
>         *mode = 0;
>         *extra = 0;
> @@ -140,12 +140,27 @@ static int shared_setxattr(const char *path, int fd,
> const char *name, const voi
>         pseudo_debug(PDBGF_XATTR, "setxattr(%s [fd %d], %s => '%.*s')\n",
>                 path ? path : "<no path>", fd, name, (int) size, (char *)
> value);
>
> +       /* Filter out erroneous sizes for POSIX ACL
> +        *  see posix_acl_xattr_count in include/linux/posix_acl_xattr.h
> of Linux source code */
> +       if (!strcmp(name, "system.posix_acl_access") || !strcmp(name,
> "system.posix_acl_default")) {
> +               // ACL is corrupt, issue an error
> +               if(size < sizeof(acl_header) || (size -
> sizeof(acl_header)) % sizeof(acl_entry) != 0) {
> +                       errno = EINVAL;
> +                       return -1;
> +               }
> +
> +               // ACL is empty, do nothing
> +               if((size - sizeof(acl_header)) / sizeof(acl_entry) == 0) {
> +                       return 0;
> +               }
> +       }
>         /* this may be a plain chmod */
>         if (!strcmp(name, "system.posix_acl_access")) {
>                 int extra;
>                 int mode;
>                 int entries = (size - sizeof(acl_header)) /
> sizeof(acl_entry);
> -               if (!posix_permissions(value, entries, &extra, &mode)) {
> +               int res = posix_permissions(value, entries, &extra, &mode);
> +               if (res == 0) {
>                         pseudo_debug(PDBGF_XATTR, "posix_acl_access
> translated to mode %04o. Remaining attribute(s): %d.\n",
>                                 mode, extra);
>                         buf.st_mode = mode;
> @@ -164,8 +179,12 @@ static int shared_setxattr(const char *path, int fd,
> const char *name, const voi
>                         if (!extra) {
>                                 return 0;
>                         }
> +               } else if (res == -1) {
> +                       errno = EOPNOTSUPP;
> +                       return -1;
>                 }
>         }
> +
>         if (!strcmp(name, "user.pseudo_data")) {
>                 pseudo_debug(PDBGF_XATTR | PDBGF_XATTRDB,
> "user.pseudo_data xattribute does not get to go in database.\n");
>                 return -1;
> --
> 2.11.1
>
> --
> _______________________________________________
> poky mailing list
> poky at yoctoproject.org
> https://lists.yoctoproject.org/listinfo/poky
>
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