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ocfs2: trusted xattr missing CAP_SYS_ADMIN check

PATCH In review Sanidhya Kashyap 2 participants 2 messages Mar 24, 2015 OCFS2

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Sanidhya Kashyap

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PATCH 1/1 ocfs2: trusted xattr missing CAP_SYS_ADMIN check

The trusted extended attributes are only visible to the process which hvae CAP_SYS_ADMIN capability but the check is missing in ocfs2 xattr_handler trusted list. The check is important because this will be used for implementing mechanisms in the userspace for which other ordinary processes should not have access to.

Signed-off-by Sanidhya Kashyap <[email protected]>
---
 fs/ocfs2/xattr.c | 3 +++
 1 file changed, 3 insertions(+)
fs/ocfs2/xattr.c +3 -0
index 85b190d..71a6551 100644
@@ -7326,6 +7326,9 @@ static size_t ocfs2_xattr_trusted_list(struct dentry *dentry, char *list,
 	const size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN;
 	const size_t total_len = prefix_len + name_len + 1;
 
+	if (!capable(CAP_SYS_ADMIN))
+		return 0;
+
 	if (list && total_len <= list_size) {
 		memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
 		memcpy(list + prefix_len, name, name_len);
Signature · 1 line
2.1.0
#1 lore raw
Quoted 11 lines · On Tue, 24 Mar 2015 11:46:32 -0400 Sanidhya Kashyap…

The trusted extended attributes are only visible to the process which hvae CAP_SYS_ADMIN capability but the check is missing in ocfs2 xattr_handler trusted list. The check is important because this will be used for implementing mechanisms in the userspace for which other ordinary processes should not have access to.

...

fs/ocfs2/xattr.c static size_t ocfs2_xattr_trusted_list(struct dentry *dentry, char *list, · line 7334

Quoted 9 lines
fs/ocfs2/xattr.c +3 -0
@@ -7326,6 +7326,9 @@ static size_t ocfs2_xattr_trusted_list(struct dentry *dentry, char *list,
 	const size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN;
 	const size_t total_len = prefix_len + name_len + 1;
 
+	if (!capable(CAP_SYS_ADMIN))
+		return 0;
+
 	if (list && total_len <= list_size) {
 		memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
 		memcpy(list + prefix_len, name, name_len);

Ouch. Won't this break existing userspace?