在 2020年05月27日 11:15, lijiang 写道: > 在 2020年05月26日 21:59, Jiri Bohac 写道: >> On Mon, May 25, 2020 at 01:23:51PM +0800, Lianbo Jiang wrote: >>> So, here, let's simplify the logic to improve code readability. If the >>> KEXEC_SIG_FORCE enabled or kexec lockdown enabled, signature verification >>> is mandated. Otherwise, we lift the bar for any kernel image. >> >> I agree completely; in fact that was my intention when >> introducing the code, but I got overruled about the return codes: >> https://lore.kernel.org/lkml/20180119125425.l72meyyc2qtrriwe@xxxxxxxxxxxxx/ >> >> I like this simplification very much, except this part: >> >>> + if (ret) { >>> + pr_debug("kernel signature verification failed (%d).\n", ret); >> >> ... >> >>> - pr_notice("kernel signature verification failed (%d).\n", ret); >> >> I think the log level should stay at most PR_NOTICE when the >> verification failure results in rejecting the kernel. Perhaps >> even lower. >> > > Thank you for the comment, Jiri Bohac. > > I like the idea of staying at most PR_NOTICE, but the pr_notice() will output > some messages that kernel could want to ignore, such as the case you mentioned > below. > >> In case verification is not enforced and the failure is >> ignored, KERN_DEBUG seems reasonable. >> > > Yes, good understanding. It seems that the pr_debug() is still a good option here? > Any other thoughts? > Or the following change looks better? What's your opinion? static int kimage_validate_signature(struct kimage *image) { int ret; ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf, image->kernel_buf_len); if (ret) { if (IS_ENABLED(CONFIG_KEXEC_SIG_FORCE)) { pr_notice("Enforced kernel signature verification failed (%d).\n", ret); return ret; } /* * If IMA is guaranteed to appraise a signature on the kexec * image, permit it even if the kernel is otherwise locked * down. */ if (!ima_appraise_signature(READING_KEXEC_IMAGE) && security_locked_down(LOCKDOWN_KEXEC)) return -EPERM; pr_debug("kernel signature verification failed (%d).\n", ret); } return 0; } Thanks. Lianbo > Thanks. > Lianbo > > >> Regards, >> _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
