linux-kernel - [PATCH AUTOSEL 6.12 146/486] printk: Check CON

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250505223922.2682012-146-sashal@kernel.org>
Date: Mon,  5 May 2025 18:33:42 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Marcos Paulo de Souza <mpdesouza@...e.com>,
	Petr Mladek <pmladek@...e.com>,
	John Ogness <john.ogness@...utronix.de>,
	Sasha Levin <sashal@...nel.org>
Subject: [PATCH AUTOSEL 6.12 146/486] printk: Check CON_SUSPEND when unblanking a console

From: Marcos Paulo de Souza <mpdesouza@...e.com>

[ Upstream commit 72c96a2dacc0fb056d13a5f02b0845c4c910fe54 ]

The commit 9e70a5e109a4 ("printk: Add per-console suspended state")
introduced the CON_SUSPENDED flag for consoles. The suspended consoles
will stop receiving messages, so don't unblank suspended consoles
because it won't be showing anything either way.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@...e.com>
Reviewed-by: Petr Mladek <pmladek@...e.com>
Reviewed-by: John Ogness <john.ogness@...utronix.de>
Link: https://lore.kernel.org/r/20250226-printk-renaming-v1-5-0b878577f2e6@suse.com
Signed-off-by: Petr Mladek <pmladek@...e.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 kernel/printk/printk.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 881a26e18c658..3a91b739e8f30 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -3310,7 +3310,12 @@ void console_unblank(void)
 	 */
 	cookie = console_srcu_read_lock();
 	for_each_console_srcu(c) {
-		if ((console_srcu_read_flags(c) & CON_ENABLED) && c->unblank) {
+		short flags = console_srcu_read_flags(c);
+
+		if (flags & CON_SUSPENDED)
+			continue;
+
+		if ((flags & CON_ENABLED) && c->unblank) {
 			found_unblank = true;
 			break;
 		}
@@ -3347,7 +3352,12 @@ void console_unblank(void)
 
 	cookie = console_srcu_read_lock();
 	for_each_console_srcu(c) {
-		if ((console_srcu_read_flags(c) & CON_ENABLED) && c->unblank)
+		short flags = console_srcu_read_flags(c);
+
+		if (flags & CON_SUSPENDED)
+			continue;
+
+		if ((flags & CON_ENABLED) && c->unblank)
 			c->unblank();
 	}
 	console_srcu_read_unlock(cookie);
-- 
2.39.5