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

[Anton Gerasimov]

Hi Ross,

thanks, I'll resubmit to yocto.

Best,
Anton


On 02/24/2017 03:47 PM, Burton, Ross wrote:
> 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
> <mailto:anton at advancedtelematic.com>> wrote:
>
>     From: Anton Gerasimov <anton at advancedtelematic.com
>     <mailto: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
>     <mailto: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
>
>     --
>     _______________________________________________
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>     poky at yoctoproject.org <mailto:poky at yoctoproject.org>
>     https://lists.yoctoproject.org/listinfo/poky
>     <https://lists.yoctoproject.org/listinfo/poky>
>
>

-- 
Anton Gerasimov, ATS Advanced Telematic Systems GmbH
Kantstrasse 162, 10623 Berlin
Managing Directors: Dirk Pöschl, Armin G. Schmidt
Register Court: HRB 151501 B, Amtsgericht Charlottenburg

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