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| author | Randy Dunlap <rdunlap@infradead.org> | 2022-03-22 22:47:52 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-22 23:57:11 +0100 |
| commit | 05fe3c103f7e6b8b4fca8a7001dfc9ed4628085b (patch) | |
| tree | 939f4d52d2c04a3eb05146792898c0bd78e599e6 | |
| parent | mm: uninline copy_overflow() (diff) | |
| download | linux-05fe3c103f7e6b8b4fca8a7001dfc9ed4628085b.tar.xz linux-05fe3c103f7e6b8b4fca8a7001dfc9ed4628085b.zip | |
mm/usercopy: return 1 from hardened_usercopy __setup() handler
__setup() handlers should return 1 if the command line option is handled
and 0 if not (or maybe never return 0; it just pollutes init's
environment). This prevents:
Unknown kernel command line parameters \
"BOOT_IMAGE=/boot/bzImage-517rc5 hardened_usercopy=off", will be \
passed to user space.
Run /sbin/init as init process
with arguments:
/sbin/init
with environment:
HOME=/
TERM=linux
BOOT_IMAGE=/boot/bzImage-517rc5
hardened_usercopy=off
or
hardened_usercopy=on
but when "hardened_usercopy=foo" is used, there is no Unknown kernel
command line parameter.
Return 1 to indicate that the boot option has been handled.
Print a warning if strtobool() returns an error on the option string,
but do not mark this as in unknown command line option and do not cause
init's environment to be polluted with this string.
Link: https://lkml.kernel.org/r/20220222034249.14795-1-rdunlap@infradead.org
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Fixes: b5cb15d9372ab ("usercopy: Allow boot cmdline disabling of hardening")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Acked-by: Chris von Recklinghausen <crecklin@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/usercopy.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/mm/usercopy.c b/mm/usercopy.c index e7b0cb49daa1..bf4d57fefee1 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -284,7 +284,10 @@ static bool enable_checks __initdata = true; static int __init parse_hardened_usercopy(char *str) { - return strtobool(str, &enable_checks); + if (strtobool(str, &enable_checks)) + pr_warn("Invalid option string for hardened_usercopy: '%s'\n", + str); + return 1; } __setup("hardened_usercopy=", parse_hardened_usercopy); |