| Message ID | 20230314081720.4158676-2-roberto.sassu@huaweicloud.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | evm: Do HMAC of multiple per LSM xattrs for new inodes | expand |
On Tue, Mar 14, 2023 at 4:18 AM Roberto Sassu <roberto.sassu@huaweicloud.com> wrote: > > From: Roberto Sassu <roberto.sassu@huawei.com> > > In preparation for removing security_old_inode_init_security(), switch to > security_inode_init_security(). Commit 572302af1258 ("reiserfs: Add missing > calls to reiserfs_security_free()") fixed possible memory leaks and another > issue related to adding an xattr at inode creation time. > > Define the initxattrs callback reiserfs_initxattrs(), to populate the > name/value/len triple in the reiserfs_security_handle() with the first > xattr provided by LSMs. Make a copy of the xattr value, as > security_inode_init_security() frees it. > > After the call to security_inode_init_security(), remove the check for > returning -EOPNOTSUPP, as security_inode_init_security() changes it to > zero. > > Multiple xattrs are currently not supported, as the > reiserfs_security_handle structure is exported to user space. As a > consequence, even if EVM is invoked, it will not provide an xattr (if it > is not the first to set it, its xattr will be discarded; if it is the > first, it does not have xattrs to calculate the HMAC on). > > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> > Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> > Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> > --- > fs/reiserfs/xattr_security.c | 23 ++++++++++++++++++----- > 1 file changed, 18 insertions(+), 5 deletions(-) Merged into lsm/next, thanks.
diff --git a/fs/reiserfs/xattr_security.c b/fs/reiserfs/xattr_security.c index 41c0ea84fbf..6bffdf9a4fd 100644 --- a/fs/reiserfs/xattr_security.c +++ b/fs/reiserfs/xattr_security.c @@ -39,6 +39,22 @@ static bool security_list(struct dentry *dentry) return !IS_PRIVATE(d_inode(dentry)); } +static int +reiserfs_initxattrs(struct inode *inode, const struct xattr *xattr_array, + void *fs_info) +{ + struct reiserfs_security_handle *sec = fs_info; + + sec->value = kmemdup(xattr_array->value, xattr_array->value_len, + GFP_KERNEL); + if (!sec->value) + return -ENOMEM; + + sec->name = xattr_array->name; + sec->length = xattr_array->value_len; + return 0; +} + /* Initializes the security context for a new inode and returns the number * of blocks needed for the transaction. If successful, reiserfs_security * must be released using reiserfs_security_free when the caller is done. */ @@ -56,12 +72,9 @@ int reiserfs_security_init(struct inode *dir, struct inode *inode, if (IS_PRIVATE(dir)) return 0; - error = security_old_inode_init_security(inode, dir, qstr, &sec->name, - &sec->value, &sec->length); + error = security_inode_init_security(inode, dir, qstr, + &reiserfs_initxattrs, sec); if (error) { - if (error == -EOPNOTSUPP) - error = 0; - sec->name = NULL; sec->value = NULL; sec->length = 0;