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: b1ae6dc41e ("module: add in-kernel support for decompressing")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
This commit is contained in:
Dmitry Torokhov 2022-01-13 16:51:52 -08:00 committed by Luis Chamberlain
parent 285ac8dca4
commit a97ac8cb24

View File

@ -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 */