From: Gu Zheng <guzheng1@xxxxxxxxxx>
commit 497de07d89c1410d76a15bec2bb41f24a2a89f31 upstream.
This change was missed the tmpfs modification in In CVE-2016-7097
commit 073931017b49 ("posix_acl: Clear SGID bit when setting
file permissions")
It can test by xfstest generic/375, which failed to clear
setgid bit in the following test case on tmpfs:
touch $testfile
chown 100:100 $testfile
chmod 2755 $testfile
_runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile
Signed-off-by: Gu Zheng <guzheng1@xxxxxxxxxx>
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Willy Tarreau <w@xxxxxx>
---
fs/generic_acl.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/fs/generic_acl.c b/fs/generic_acl.c
index b3f3676..7855cfb 100644
--- a/fs/generic_acl.c
+++ b/fs/generic_acl.c
@@ -82,19 +82,21 @@ generic_acl_set(struct dentry *dentry, const char *name, const void *value,
return PTR_ERR(acl);
}
if (acl) {
+ struct posix_acl *old_acl;
+
error = posix_acl_valid(acl);
if (error)
goto failed;
switch (type) {
case ACL_TYPE_ACCESS:
- error = posix_acl_equiv_mode(acl, &inode->i_mode);
+ old_acl = acl;
+ error = posix_acl_update_mode(inode, &inode->i_mode,
+ &acl);
if (error < 0)
goto failed;
+ if (!acl)
+ posix_acl_release(old_acl);
inode->i_ctime = CURRENT_TIME;
- if (error == 0) {
- posix_acl_release(acl);
- acl = NULL;
- }
break;
case ACL_TYPE_DEFAULT:
if (!S_ISDIR(inode->i_mode)) {
--
2.8.0.rc2.1.gbe9624a