From: Kees Cook Date: Fri, 24 Jul 2020 21:36:24 +0000 (-0700) Subject: firmware_loader: EFI firmware loader must handle pre-allocated buffer X-Git-Tag: v5.7.16~14 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3f29275098737306d6597ad7fd6983633120722b;p=thirdparty%2Fkernel%2Fstable.git firmware_loader: EFI firmware loader must handle pre-allocated buffer commit 4fb60b158afd3ac9e0fe9975aa476213f5cc0a4d upstream. The EFI platform firmware fallback would clobber any pre-allocated buffers. Instead, correctly refuse to reallocate when too small (as already done in the sysfs fallback), or perform allocation normally when needed. Fixes: e4c2c0ff00ec ("firmware: Add new platform fallback mechanism and firmware_request_platform()") Cc: stable@vger.kernel.org Acked-by: Scott Branden Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20200724213640.389191-4-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/base/firmware_loader/fallback_platform.c b/drivers/base/firmware_loader/fallback_platform.c index c88c745590feb..723ff8bcf3e76 100644 --- a/drivers/base/firmware_loader/fallback_platform.c +++ b/drivers/base/firmware_loader/fallback_platform.c @@ -25,7 +25,10 @@ int firmware_fallback_platform(struct fw_priv *fw_priv, enum fw_opt opt_flags) if (rc) return rc; /* rc == -ENOENT when the fw was not found */ - fw_priv->data = vmalloc(size); + if (fw_priv->data && size > fw_priv->allocated_size) + return -ENOMEM; + if (!fw_priv->data) + fw_priv->data = vmalloc(size); if (!fw_priv->data) return -ENOMEM;