Use the return value of listxattr instead of tokenizing.
The end of the extended attribute list is indicated by the return
value, not an empty list item (two consecutive NULs). Using strtok
in this way thus sometimes caused add_xattr_item to reuse stack data
in xattr_list from the previous invocation, thus querying attributes
that are not actually in the file's xattr list.
Issue: #194
Signed-off-by: Vladimir Panteleev <g...@vladimir.panteleev.md>
---
mkfs/rootdir.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/mkfs/rootdir.c b/mkfs/rootdir.c
index 51411e02..c86159e7 100644
--- a/mkfs/rootdir.c
+++ b/mkfs/rootdir.c
@@ -228,10 +228,9 @@ static int add_xattr_item(struct btrfs_trans_handle *trans,
int ret;
int cur_name_len;
char xattr_list[XATTR_LIST_MAX];
+ char *xattr_list_end;
char *cur_name;
char cur_value[XATTR_SIZE_MAX];
- char delimiter = '\0';
- char *next_location = xattr_list;
ret = llistxattr(file_name, xattr_list, XATTR_LIST_MAX);
if (ret < 0) {
@@ -243,10 +242,10 @@ static int add_xattr_item(struct btrfs_trans_handle
*trans,
if (ret == 0)
return ret;
- cur_name = strtok(xattr_list, &delimiter);
- while (cur_name != NULL) {
+ xattr_list_end = xattr_list + ret;
+ cur_name = xattr_list;
+ while (cur_name < xattr_list_end) {
cur_name_len = strlen(cur_name);
- next_location += cur_name_len + 1;
ret = lgetxattr(file_name, cur_name, cur_value, XATTR_SIZE_MAX);
if (ret < 0) {
@@ -266,7 +265,7 @@ static int add_xattr_item(struct btrfs_trans_handle *trans,
file_name);
}
- cur_name = strtok(next_location, &delimiter);
+ cur_name += cur_name_len + 1;
}
return ret;
--
2.23.0
