mirrors/libguestfs
1
0
Fork 0
mirror of https://github.com/libguestfs/libguestfs.git synced 2026-03-21 22:53:37 +00:00
Code Issues Packages Projects Releases Wiki Activity

daemon: xattr: Filter out user.WofCompressedData from xattrs (RHBZ#1811539).

Browse Source 
See comment in code for justification.

Thanks: Yongkui Guo for finding the bug.
This commit is contained in:
Richard W.M. Jones
2020-03-12 14:40:05 +00:00
parent af8ed266a2
commit c2c11382bb
1 changed files with 40 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

43
daemon/xattr.c
View File

@@ -19,6 +19,8 @@
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <limits.h>
#include <unistd.h>
@@ -119,6 +121,29 @@ split_attr_names (char *buf, size_t len)
return take_stringsbuf (&ret);
}
/* We hide one extended attribute automatically. This is used by NTFS
* to store the compressed contents of a file when using "CompactOS"
* (per-file compression). I justify this by:
*
* (1) The attribute is only used internally by NTFS. The actual file
* contents are still available.
*
* (2) It's probably not valid to copy this attribute when copying the
* other attributes of a file. ntfs-3g-system-compression doesn't
* support writing compressed files.
*
* (3) This file isn't readable by the Linux kernel. Reading it will
* always return -E2BIG (RHBZ#1811539). So we can't read it even if
* we wanted to.
*
* (4) The Linux kernel itself hides other attributes.
*/
static bool
not_hidden_xattr (const char *attrname)
{
return STRNEQ (attrname, "user.WofCompressedData");
}
static int
compare_xattrs (const void *vxa1, const void *vxa2)
{
@@ -136,6 +161,7 @@ getxattrs (const char *path,
{
ssize_t len, vlen;
CLEANUP_FREE char *buf = NULL;
CLEANUP_FREE /* not string list */ char **names_unfiltered = NULL;
CLEANUP_FREE /* not string list */ char **names = NULL;
size_t i;
guestfs_int_xattr_list *r = NULL;
@@ -145,7 +171,10 @@ getxattrs (const char *path,
/* _listxattrs issues reply_with_perror already. */
goto error;
names = split_attr_names (buf, len);
names_unfiltered = split_attr_names (buf, len);
if (names_unfiltered == NULL)
goto error;
names = filter_list (not_hidden_xattr, names_unfiltered);
if (names == NULL)
goto error;
@@ -323,6 +352,7 @@ do_internal_lxattrlist (const char *path, char *const *names)
void *newptr;
CLEANUP_FREE char *pathname = NULL;
CLEANUP_FREE char *buf = NULL;
CLEANUP_FREE /* not string list */ char **attrnames_unfiltered = NULL;
CLEANUP_FREE /* not string list */ char **attrnames = NULL;
/* Be careful in this loop about which errors cause the whole call
@@ -381,7 +411,10 @@ do_internal_lxattrlist (const char *path, char *const *names)
if (len == -1)
continue; /* not fatal */
attrnames = split_attr_names (buf, len);
attrnames_unfiltered = split_attr_names (buf, len);
if (attrnames_unfiltered == NULL)
goto error;
attrnames = filter_list (not_hidden_xattr, attrnames_unfiltered);
if (attrnames == NULL)
goto error;
nr_attrs = guestfs_int_count_strings (attrnames);
@@ -539,6 +572,7 @@ copy_xattrs (const char *src, const char *dest)
{
ssize_t len, vlen, ret, attrval_len = 0;
CLEANUP_FREE char *buf = NULL, *attrval = NULL;
CLEANUP_FREE /* not string list */ char **names_unfiltered = NULL;
CLEANUP_FREE /* not string list */ char **names = NULL;
size_t i;
@@ -547,7 +581,10 @@ copy_xattrs (const char *src, const char *dest)
/* _listxattrs issues reply_with_perror already. */
goto error;
names = split_attr_names (buf, len);
names_unfiltered = split_attr_names (buf, len);
if (names_unfiltered == NULL)
goto error;
names = filter_list (not_hidden_xattr, names_unfiltered);
if (names == NULL)
goto error;