[RFC PATCH ghak100 V1 2/2] audit: moar filter PATH records keyed on filesystem magic

Like 42d5e37654e4 ("audit: filter PATH records keyed on filesystem magic") Any user or remote filesystem could become unavailable and effectively block on a forced unmount. -a always,exit -S umount2 -F key=umount2 Provide a method to ignore these user and remote filesystems to prevent them from being impossible to unmount. Extend the "AUDIT_FILTER_FS" filter that uses the field type AUDIT_FSTYPE keying off the filesystem 4-octet hexadecimal magic identifier to filter specific filesystems to cover audit_inode() to address this blockage. An example rule would look like: -a never,filesystem -F fstype=0x517B -F key=ignore_smb -a never,filesystem -F fstype=0x6969 -F key=ignore_nfs Arguably the better way to address this issue is to disable auditing processes that touch removable filesystems. Please see the github issue tracker https://github.com/linux-audit/audit-kernel/issues/100 Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; --- kernel/auditsc.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index d39a7fbaf944..59d6d3fbc00e 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1777,10 +1777,33 @@ void __audit_inode(struct filename *name, const struct dentry *dentry, struct inode *inode = d_backing_inode(dentry); struct audit_names *n; bool parent = flags & AUDIT_INODE_PARENT; + struct audit_entry *e; + struct list_head *list = &audit_filter_list[AUDIT_FILTER_FS]; + int i; if (!context->in_syscall) return; + rcu_read_lock(); + if (!list_empty(list)) { + list_for_each_entry_rcu(e, list, list) { + for (i = 0; i < e->rule.field_count; i++) { + struct audit_field *f = &e->rule.fields[i]; + + if (f->type == AUDIT_FSTYPE) { + if (audit_comparator(inode->i_sb->s_magic, + f->op, f->val)) { + if (e->rule.action == AUDIT_NEVER) { + rcu_read_unlock(); + return; + } + } + } + } + } + } + rcu_read_unlock(); + if (!name) goto out_alloc; -- 1.8.3.1