Hi Roberto, On Thu, 2022-11-10 at 10:46 +0100, Roberto Sassu wrote: > From: Roberto Sassu <roberto.sassu@xxxxxxxxxx> > > Rewrite security_old_inode_init_security() to call > security_inode_init_security() before making changes to support multiple > LSMs providing xattrs. Do it so that the required changes are done only in > one place. Only security_inode_init_security() has support for EVM. Making security_old_inode_init_security() a wrapper for security_inode_init_security() could result in security.evm extended attributes being created that previously weren't created. In fact ocfs2 defines ocfs2_init_security_get() as a wrapper for both the old and new inode_init_security calls based on the caller's preference. Only mknod and symlink seem to use the old function. Wondering why do they differentiate between callers? (Cc'ing the ocfs2 mailing list as they're affected by this change.) "[PATCH v4 1/5] reiserfs: Add missing calls to reiserfs_security_free()" fixed a memory leak. I couldn't tell if there was a similar memory leak in ocfs2, the only other user of security_old_inode_init_security(). As ocfs2 already defines initxattrs, that leaves only reiserfs missing initxattrs(). A better, cleaner solution would be to define one. thanks, Mimi > > Define the security_initxattrs() callback and pass it to > security_inode_init_security() as argument, to obtain the first xattr > provided by LSMs. > > This behavior is a bit different from the current one. Before this patch > calling call_int_hook() could cause multiple LSMs to provide an xattr, > since call_int_hook() does not stop when an LSM returns zero. The caller of > security_old_inode_init_security() receives the last xattr set. The pointer > of the xattr value of previous LSMs is lost, causing memory leaks. > > However, in practice, this scenario does not happen as the only in-tree > LSMs providing an xattr at inode creation time are SELinux and Smack, which > are mutually exclusive. > > Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>b
