From 0a98b51d79e78082bf4b5c0665436da2dd36f4bb Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Tue, 5 Jul 2022 17:44:26 +0800 Subject: [PATCH] EVM: fix the evm= __setup handler return value stable inclusion from stable-v5.10.110 commit d788ad472f83fc92df76deb7fff738d4d69329a2 bugzilla: https://gitee.com/openeuler/kernel/issues/I574AL Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d788ad472f83fc92df76deb7fff738d4d69329a2 -------------------------------- [ Upstream commit f2544f5e6c691679d56bb38637d2f347075b36fa ] __setup() handlers should return 1 if the parameter is handled. Returning 0 causes the entire string to be added to init's environment strings (limited to 32 strings), unnecessarily polluting it. Using the documented string "evm=fix" causes an Unknown parameter message: Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc5 evm=fix", will be passed to user space. and that string is added to init's environment string space: Run /sbin/init as init process with arguments: /sbin/init with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc5 evm=fix With this change, using "evm=fix" acts as expected and an invalid option ("evm=evm") causes a warning to be printed: evm: invalid "evm" mode but init's environment is not polluted with this string, as expected. Fixes: 7102ebcd65c1 ("evm: permit only valid security.evm xattrs to be updated") Signed-off-by: Randy Dunlap Reported-by: Igor Zhbanov Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin Signed-off-by: Yu Liao Reviewed-by: Wei Li Signed-off-by: Zheng Zengkai --- security/integrity/evm/evm_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index f3dd2641d29a..cddfc0e43a80 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -70,7 +70,7 @@ static int __init evm_set_param(char *str) else pr_err("invalid \"%s\" mode", str); - return 0; + return 1; } __setup("evm=", evm_set_param); -- GitLab