Thread (52 messages) 52 messages, 11 authors, 2022-01-05

[PATCH V40 29/29] lockdown: Print current->comm in restriction messages

From: Matthew Garrett <hidden>
Date: 2019-08-20 00:19:35
Also in: linux-api, lkml
Subsystem: filesystems (vfs and infrastructure), kcore, lockdown security module, proc filesystem, security subsystem, the rest · Maintainers: Alexander Viro, Christian Brauner, Omar Sandoval, Nicolas Bouchinet, Xiu Jianfeng, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds

Print the content of current->comm in messages generated by lockdown to
indicate a restriction that was hit.  This makes it a bit easier to find
out what caused the message.

The message now patterned something like:

        Lockdown: <comm>: <what> is restricted; see man kernel_lockdown.7

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <redacted>
Reviewed-by: Kees Cook <redacted>
Signed-off-by: James Morris <jmorris@namei.org>
---
 fs/proc/kcore.c              | 5 +++--
 security/lockdown/lockdown.c | 8 ++++++--
 2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index ee2c576cc94e..e2ed8e08cc7a 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -548,11 +548,12 @@ static int open_kcore(struct inode *inode, struct file *filp)
 {
 	int ret = security_locked_down(LOCKDOWN_KCORE);
 
-	if (ret)
-		return ret;
 	if (!capable(CAP_SYS_RAWIO))
 		return -EPERM;
 
+	if (ret)
+		return ret;
+
 	filp->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!filp->private_data)
 		return -ENOMEM;
diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c
index 84df03b1f5a7..0068cec77c05 100644
--- a/security/lockdown/lockdown.c
+++ b/security/lockdown/lockdown.c
@@ -81,10 +81,14 @@ early_param("lockdown", lockdown_param);
  */
 static int lockdown_is_locked_down(enum lockdown_reason what)
 {
+	if (WARN(what >= LOCKDOWN_CONFIDENTIALITY_MAX,
+		 "Invalid lockdown reason"))
+		return -EPERM;
+
 	if (kernel_locked_down >= what) {
 		if (lockdown_reasons[what])
-			pr_notice("Lockdown: %s is restricted; see man kernel_lockdown.7\n",
-				  lockdown_reasons[what]);
+			pr_notice("Lockdown: %s: %s is restricted; see man kernel_lockdown.7\n",
+				  current->comm, lockdown_reasons[what]);
 		return -EPERM;
 	}
 
-- 
2.23.0.rc1.153.gdeed80330f-goog
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