Commit a97ac8cb authored by Dmitry Torokhov's avatar Dmitry Torokhov Committed by Luis Chamberlain
Browse files

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: b1ae6dc4 ("module: add in-kernel support for decompressing")
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: default avatarDouglas Anderson <dianders@chromium.org>
Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
parent 285ac8dc

kernel/module.c

+5 −4
Original line number Diff line number Diff line
@@ -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 */