thinkpad-acpi: lock down video output state access
authorHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Fri, 26 Feb 2010 01:22:22 +0000 (22:22 -0300)
committerHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Fri, 26 Feb 2010 01:22:22 +0000 (22:22 -0300)
commitb525c06cdbd8a3963f0173ccd23f9147d4c384b5
tree025b22fda39fc7a42061ab25a908abe3ae757d3b
parent08fedfc903c78e380b0baa7b57c52d367794d0a5
thinkpad-acpi: lock down video output state access

Given the right combination of ThinkPad and X.org, just reading the
video output control state is enough to hard-crash X.org.

Until the day I somehow find out a model or BIOS cut date to not
provide this feature to ThinkPads that can do video switching through
X RandR, change permissions so that only processes with CAP_SYS_ADMIN
can access any sort of video output control state.

This bug could be considered a local DoS I suppose, as it allows any
non-privledged local user to cause some versions of X.org to
hard-crash some ThinkPads.

Reported-by: Jidanni <jidanni@jidanni.org>
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: stable@kernel.org
Documentation/laptops/thinkpad-acpi.txt
drivers/platform/x86/Kconfig
drivers/platform/x86/thinkpad_acpi.c