This patch will print cap_permitted and cap_inheritable data in the PATH

records of any file that has file capabilities set.  Files which do not
have fcaps set will not have different PATH records.

An example audit record if you run:
setcap "cap_net_admin+pie" /bin/bash
/bin/bash

type=SYSCALL msg=audit(1225741937.363:230): arch=c000003e syscall=59 success=yes exit=0 a0=2119230 a1=210da30 a2=20ee290 a3=8 items=2 ppid=2149 pid=2923 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=3 comm="ping" exe="/bin/ping" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=EXECVE msg=audit(1225741937.363:230): argc=2 a0="ping" a1="www.google.com"
type=CWD msg=audit(1225741937.363:230):  cwd="/root"
type=PATH msg=audit(1225741937.363:230): item=0 name="/bin/ping" inode=49256 dev=fd:00 mode=0104755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ping_exec_t:s0 cap_fp=0000000000002000 cap_fi=0000000000002000 cap_fe=1 cap_fver=2
type=PATH msg=audit(1225741937.363:230): item=1 name=(null) inode=507915 dev=fd:00 mode=0100755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ld_so_t:s0

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 77 insertions, 5 deletions

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index cf5bc2f5f9c3..de7e9bcba9ae 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -65,6 +65,7 @@
 #include <linux/highmem.h>
 #include <linux/syscalls.h>
 #include <linux/inotify.h>
+#include <linux/capability.h>
 
 #include "audit.h"
 
@@ -84,6 +85,15 @@ int audit_n_rules;
 /* determines whether we collect data for signals sent */
 int audit_signals;
 
+struct audit_cap_data {
+        kernel_cap_t            permitted;
+        kernel_cap_t            inheritable;
+        union {
+                unsigned int    fE;             /* effective bit of a file capability */
+                kernel_cap_t    effective;      /* effective set of a process */
+        };
+};
+
 /* When fs/namei.c:getname() is called, we store the pointer in name and
  * we don't let putname() free it (instead we free all of the saved
  * pointers at syscall exit time).
@@ -100,6 +110,8 @@ struct audit_names {
         gid_t           gid;
         dev_t           rdev;
         u32             osid;
+        struct audit_cap_data fcap;
+        unsigned int    fcap_ver;
 };
 
 struct audit_aux_data {
@@ -1171,6 +1183,35 @@ static void audit_log_execve_info(struct audit_context *context,
         kfree(buf);
 }
 
+static void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
+{
+        int i;
+
+        audit_log_format(ab, " %s=", prefix);
+        CAP_FOR_EACH_U32(i) {
+                audit_log_format(ab, "%08x", cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]);
+        }
+}
+
+static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
+{
+        kernel_cap_t *perm = &name->fcap.permitted;
+        kernel_cap_t *inh = &name->fcap.inheritable;
+        int log = 0;
+
+        if (!cap_isclear(*perm)) {
+                audit_log_cap(ab, "cap_fp", perm);
+                log = 1;
+        }
+        if (!cap_isclear(*inh)) {
+                audit_log_cap(ab, "cap_fi", inh);
+                log = 1;
+        }
+
+        if (log)
+                audit_log_format(ab, " cap_fe=%d cap_fver=%x", name->fcap.fE, name->fcap_ver);
+}
+
 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
 {
         int i, call_panic = 0;
@@ -1421,6 +1462,8 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
                         }
                 }
 
+                audit_log_fcaps(ab, n);
+
                 audit_log_end(ab);
         }
 
@@ -1787,8 +1830,36 @@ static int audit_inc_name_count(struct audit_context *context,
         return 0;
 }
 
+
+static inline int audit_copy_fcaps(struct audit_names *name, const struct dentry *dentry)
+{
+        struct cpu_vfs_cap_data caps;
+        int rc;
+
+        memset(&name->fcap.permitted, 0, sizeof(kernel_cap_t));
+        memset(&name->fcap.inheritable, 0, sizeof(kernel_cap_t));
+        name->fcap.fE = 0;
+        name->fcap_ver = 0;
+
+        if (!dentry)
+                return 0;
+
+        rc = get_vfs_caps_from_disk(dentry, &caps);
+        if (rc)
+                return rc;
+
+        name->fcap.permitted = caps.permitted;
+        name->fcap.inheritable = caps.inheritable;
+        name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
+        name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
+
+        return 0;
+}
+
+
 /* Copy inode data into an audit_names. */
-static void audit_copy_inode(struct audit_names *name, const struct inode *inode)
+static void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
+                             const struct inode *inode)
 {
         name->ino   = inode->i_ino;
         name->dev   = inode->i_sb->s_dev;
@@ -1797,6 +1868,7 @@ static void audit_copy_inode(struct audit_names *name, const struct inode *inode
         name->gid   = inode->i_gid;
         name->rdev  = inode->i_rdev;
         security_inode_getsecid(inode, &name->osid);
+        audit_copy_fcaps(name, dentry);
 }
 
 /**
@@ -1831,7 +1903,7 @@ void __audit_inode(const char *name, const struct dentry *dentry)
                 context->names[idx].name = NULL;
         }
         handle_path(dentry);
-        audit_copy_inode(&context->names[idx], inode);
+        audit_copy_inode(&context->names[idx], dentry, inode);
 }
 
 /**
@@ -1892,7 +1964,7 @@ void __audit_inode_child(const char *dname, const struct dentry *dentry,
                 if (!strcmp(dname, n->name) ||
                      !audit_compare_dname_path(dname, n->name, &dirlen)) {
                         if (inode)
-                                audit_copy_inode(n, inode);
+                                audit_copy_inode(n, NULL, inode);
                         else
                                 n->ino = (unsigned long)-1;
                         found_child = n->name;
@@ -1906,7 +1978,7 @@ add_names:
                         return;
                 idx = context->name_count - 1;
                 context->names[idx].name = NULL;
-                audit_copy_inode(&context->names[idx], parent);
+                audit_copy_inode(&context->names[idx], NULL, parent);
         }
 
         if (!found_child) {
@@ -1927,7 +1999,7 @@ add_names:
                 }
 
                 if (inode)
-                        audit_copy_inode(&context->names[idx], inode);
+                        audit_copy_inode(&context->names[idx], NULL, inode);
                 else
                         context->names[idx].ino = (unsigned long)-1;
         }