Commit 497de07d authored Jan 09, 2017 by Gu Zheng Committed by Al Viro Jan 10, 2017

tmpfs: clear S_ISGID when setting posix ACLs



This change was missed the tmpfs modification in In CVE-2016-7097
commit 07393101 ("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@huawei.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

parent b4b8664d

fs/posix_acl.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -922,11 +922,10 @@ int simple_set_acl(struct inode inode, struct posix_acl acl, int type)
		int error;

		if (type == ACL_TYPE_ACCESS) {
		error = posix_acl_equiv_mode(acl, &inode->i_mode);
		if (error < 0)
		return 0;
		if (error == 0)
		acl = NULL;
		error = posix_acl_update_mode(inode,
		&inode->i_mode, &acl);
		if (error)
		return error;
		}

		inode->i_ctime = current_time(inode);

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