From a97ac8cb24a3c3ad74794adb83717ef1605d1b47 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Thu, 13 Jan 2022 16:51:52 -0800 Subject: module: fix signature check failures when using in-kernel decompression The new flag MODULE_INIT_COMPRESSED_FILE unintentionally trips check in module_sig_check(). The check was supposed to catch case when version info or magic was removed from a signed module, making signature invalid, but it was coded too broadly and was catching this new flag as well. Change the check to only test the 2 particular flags affecting signature validity. Fixes: b1ae6dc41eaa ("module: add in-kernel support for decompressing") Signed-off-by: Dmitry Torokhov Reviewed-by: Douglas Anderson Signed-off-by: Luis Chamberlain --- kernel/module.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/module.c b/kernel/module.c index 34fe2824eb56..387ee77bdbd6 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2883,12 +2883,13 @@ static int module_sig_check(struct load_info *info, int flags) const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; const char *reason; const void *mod = info->hdr; - + bool mangled_module = flags & (MODULE_INIT_IGNORE_MODVERSIONS | + MODULE_INIT_IGNORE_VERMAGIC); /* - * Require flags == 0, as a module with version information - * removed is no longer the module that was signed + * Do not allow mangled modules as a module with version information + * removed is no longer the module that was signed. */ - if (flags == 0 && + if (!mangled_module && info->len > markerlen && memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) { /* We truncate the module to discard the signature */ -- cgit v1.2.3