From c93b5b60dc9b89b8ce71da4641057c334e8d66cd Mon Sep 17 00:00:00 2001 From: Gu Zheng Date: Mon, 9 Jan 2017 09:34:48 +0800 Subject: [PATCH] tmpfs: clear S_ISGID when setting posix ACLs 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 Signed-off-by: Al Viro Signed-off-by: Jan Kara Signed-off-by: Jiri Slaby --- 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 b3f3676796d3..7855cfb938f6 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)) {