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| author | Randy Dunlap <rdunlap@infradead.org> | 2022-02-22 13:45:18 -0800 |
|---|---|---|
| committer | Mimi Zohar <zohar@linux.ibm.com> | 2022-02-22 18:11:33 -0500 |
| commit | f2544f5e6c691679d56bb38637d2f347075b36fa (patch) | |
| tree | 4464c55205df89d88f3b3f4abcdbdcad67686b03 /security | |
| parent | cd3bc044af483422cc81a93f23c78c20c978b17c (diff) | |
| download | lwn-f2544f5e6c691679d56bb38637d2f347075b36fa.tar.gz lwn-f2544f5e6c691679d56bb38637d2f347075b36fa.zip | |
EVM: fix the evm= __setup handler return value
__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 <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Diffstat (limited to 'security')
| -rw-r--r-- | security/integrity/evm/evm_main.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 08f907382c61..7d87772f0ce6 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -86,7 +86,7 @@ static int __init evm_set_fixmode(char *str) else pr_err("invalid \"%s\" mode", str); - return 0; + return 1; } __setup("evm=", evm_set_fixmode); |