From: =?UTF-8?q?G=C3=BCnther=20Noack?= <gnoack3000@gmail.com>
Date: Tue, 8 Aug 2023 22:11:12 +0200
Subject: [PATCH] TIOCSTI: Document CAP_SYS_ADMIN behaviour in Kconfig
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References: bsc#1012628
Patch-mainline: 6.4.13
Git-commit: 3f29d9ee323ae5cda59d144d1f8b0b10ea065be0

commit 3f29d9ee323ae5cda59d144d1f8b0b10ea065be0 upstream.

Clarifies that the LEGACY_TIOCSTI setting is safe to turn off even
when running BRLTTY, as it was introduced in commit 690c8b804ad2
("TIOCSTI: always enable for CAP_SYS_ADMIN").

Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Link: https://lore.kernel.org/r/20230808201115.23993-1-gnoack3000@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 drivers/tty/Kconfig | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
index 341abaed4ce2..069de553127c 100644
--- a/drivers/tty/Kconfig
+++ b/drivers/tty/Kconfig
@@ -164,6 +164,9 @@ config LEGACY_TIOCSTI
 	  userspace depends on this functionality to continue operating
 	  normally.
 
+	  Processes which run with CAP_SYS_ADMIN, such as BRLTTY, can
+	  use TIOCSTI even when this is set to N.
+
 	  This functionality can be changed at runtime with the
 	  dev.tty.legacy_tiocsti sysctl. This configuration option sets
 	  the default value of the sysctl.
-- 
2.35.3