audit: add support for fcaps v3

V3 namespaced file capabilities were introduced in commit 8db6c34 ("Introduce v3 namespaced file capabilities") Add support for these by adding the "frootid" field to the existing fcaps fields in the NAME and BPRM_FCAPS records. Please see github issue linux-audit/audit-kernel#103 Signed-off-by: Richard Guy Briggs <[email protected]> Acked-by: Serge Hallyn <[email protected]> [PM: comment tweak to fit an 80 char line width] Signed-off-by: Paul Moore <[email protected]>
josf · Jan 25, 2019 · 2fec30e · 2fec30e
1 parent 4b7d248
commit 2fec30e
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Showing 5 changed files with 14 additions and 4 deletions.
diff --git a/include/linux/capability.h b/include/linux/capability.h
@@ -14,7 +14,7 @@
 #define _LINUX_CAPABILITY_H
 
 #include <uapi/linux/capability.h>
-
+#include <linux/uidgid.h>
 
 #define _KERNEL_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_3
 #define _KERNEL_CAPABILITY_U32S    _LINUX_CAPABILITY_U32S_3
@@ -25,11 +25,12 @@ typedef struct kernel_cap_struct {
 	__u32 cap[_KERNEL_CAPABILITY_U32S];
 } kernel_cap_t;
 
-/* exact same as vfs_cap_data but in cpu endian and always filled completely */
+/* same as vfs_ns_cap_data but in cpu endian and always filled completely */
 struct cpu_vfs_cap_data {
 	__u32 magic_etc;
 	kernel_cap_t permitted;
 	kernel_cap_t inheritable;
+	kuid_t rootid;
 };
 
 #define _USER_CAP_HEADER_SIZE  (sizeof(struct __user_cap_header_struct))

diff --git a/kernel/audit.c b/kernel/audit.c
@@ -2084,8 +2084,9 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
 {
 	audit_log_cap(ab, "cap_fp", &name->fcap.permitted);
 	audit_log_cap(ab, "cap_fi", &name->fcap.inheritable);
-	audit_log_format(ab, " cap_fe=%d cap_fver=%x",
-			 name->fcap.fE, name->fcap_ver);
+	audit_log_format(ab, " cap_fe=%d cap_fver=%x cap_frootid=%d",
+			 name->fcap.fE, name->fcap_ver,
+			 from_kuid(&init_user_ns, name->fcap.rootid));
 }
 
 static inline int audit_copy_fcaps(struct audit_names *name,
@@ -2104,6 +2105,7 @@ static inline int audit_copy_fcaps(struct audit_names *name,
 	name->fcap.permitted = caps.permitted;
 	name->fcap.inheritable = caps.inheritable;
 	name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
+	name->fcap.rootid = caps.rootid;
 	name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >>
 				VFS_CAP_REVISION_SHIFT;
 

diff --git a/kernel/audit.h b/kernel/audit.h
@@ -69,6 +69,7 @@ struct audit_cap_data {
 		kernel_cap_t	effective;	/* effective set of process */
 	};
 	kernel_cap_t		ambient;
+	kuid_t			rootid;
 };
 
 /* When fs/namei.c:getname() is called, we store the pointer in name and bump

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
@@ -1358,6 +1358,9 @@ static void audit_log_exit(void)
 			audit_log_cap(ab, "pi", &axs->new_pcap.inheritable);
 			audit_log_cap(ab, "pe", &axs->new_pcap.effective);
 			audit_log_cap(ab, "pa", &axs->new_pcap.ambient);
+			audit_log_format(ab, " frootid=%d",
+					 from_kuid(&init_user_ns,
+						   axs->fcap.rootid));
 			break; }
 
 		}
@@ -2271,6 +2274,7 @@ int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
 	ax->fcap.permitted = vcaps.permitted;
 	ax->fcap.inheritable = vcaps.inheritable;
 	ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
+	ax->fcap.rootid = vcaps.rootid;
 	ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
 
 	ax->old_pcap.permitted   = old->cap_permitted;

diff --git a/security/commoncap.c b/security/commoncap.c
@@ -643,6 +643,8 @@ int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data
 	cpu_caps->permitted.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK;
 	cpu_caps->inheritable.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK;
 
+	cpu_caps->rootid = rootkuid;
+
 	return 0;
 }