From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ED6907E794 for ; Mon, 26 Feb 2024 15:25:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708961113; cv=none; b=a+Purzu9aYUjBrYRFg1KVhyS/Z3wrXOK7U0zCZsNBhaJslt+aF25o/h7Qi5pvZMDBJlA8T6DSgGB13DDbf7HrG8MkKxZ3xDfAnRhGqJkDo9P8TKQfdK9cKn2ozlBTxMWClpUnmSPQIn8OApanapAVBKKHI3Zh9f562teLHxIr1s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708961113; c=relaxed/simple; bh=Wz3peqSOXV4dKmVdRx7esjbJxrGrcE0UlnIR0sOULR8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ZT3H0QCh+z6r0X+oi5y+Z/myXMGUi+gWava0RzzugSD4SpAy8CLfTJP2kQ30B8ths+NbXN0MZSZu4BvGyZFUfzwZU43b1Vd5Up2DXfGDpK091AbgS9u2gDgrqrl/prFIKlJeSFmTL/xM3JMJEokv9AyKI9Sw9UlDKl3Gm5J3WAs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b=Sw9TPOVA; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b=Wf46oY5s; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="Sw9TPOVA"; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="Wf46oY5s" Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id EED261FB47; Mon, 26 Feb 2024 15:25:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1708961110; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=mH19wd60ZFkQYGWsbwG2uFfjoFrKPwmGO1SmRTa2+qA=; b=Sw9TPOVAorw5k78xLTHAX5LR+cEg5fKbQWFLtFhquklO81+KwmNxFvZHnuJI7YAEFOy9Xe QDHMioc9UVxQHZ0Dc+8eber/6lciIHsjPxcZsdVeY99bTjqV81f1rGoDlv+XrTCyqqT9C4 /nHJvLwkIqEmqSqqPuEUQ3ztT9b74es= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1708961109; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=mH19wd60ZFkQYGWsbwG2uFfjoFrKPwmGO1SmRTa2+qA=; b=Wf46oY5sIJQVK+oO3JIiTcQR80AVs/cPjhG1wbRS8F0H552DB/6bYQgBGD5qntS8bTUlp1 BfOui31IGcxvd7RnRSLTIcdFgtzjNpUqcXl15Cmq4A51MEwig9saCZbah8aP0GHFso1jvU d3C5y6X1E9+Pn6XgxOt31GGMsClAC5Q= Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id D39BC13A58; Mon, 26 Feb 2024 15:25:09 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id LRu2MVWt3GWPfQAAD6G6ig (envelope-from ); Mon, 26 Feb 2024 15:25:09 +0000 Date: Mon, 26 Feb 2024 16:25:09 +0100 From: Michal Hocko To: Greg Kroah-Hartman Cc: cve@kernel.org, linux-kernel@vger.kernel.org Subject: Re: CVE-2023-52451: powerpc/pseries/memhp: Fix access beyond end of drmem array Message-ID: References: <2024022257-CVE-2023-52451-7bdb@gregkh> <2024022639-wronged-grafted-6777@gregkh> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2024022639-wronged-grafted-6777@gregkh> Authentication-Results: smtp-out2.suse.de; dkim=pass header.d=suse.com header.s=susede1 header.b=Wf46oY5s X-Spamd-Result: default: False [-4.81 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; R_DKIM_ALLOW(-0.20)[suse.com:s=susede1]; SPAMHAUS_XBL(0.00)[2a07:de40:b281:104:10:150:64:97:from]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DWL_DNSWL_MED(-2.00)[suse.com:dkim]; RCVD_COUNT_THREE(0.00)[3]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; DKIM_TRACE(0.00)[suse.com:+]; MX_GOOD(-0.01)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:dkim]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; MID_RHS_NOT_FQDN(0.50)[]; RCVD_TLS_ALL(0.00)[]; BAYES_HAM(-3.00)[100.00%] X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Rspamd-Queue-Id: EED261FB47 X-Spam-Level: X-Spam-Score: -4.81 X-Spam-Flag: NO On Mon 26-02-24 16:06:51, Greg KH wrote: > On Mon, Feb 26, 2024 at 03:52:11PM +0100, Michal Hocko wrote: > > On Thu 22-02-24 17:21:58, Greg KH wrote: > > > Description > > > =========== > > > > > > In the Linux kernel, the following vulnerability has been resolved: > > > > > > powerpc/pseries/memhp: Fix access beyond end of drmem array > > > > > > dlpar_memory_remove_by_index() may access beyond the bounds of the > > > drmem lmb array when the LMB lookup fails to match an entry with the > > > given DRC index. When the search fails, the cursor is left pointing to > > > &drmem_info->lmbs[drmem_info->n_lmbs], which is one element past the > > > last valid entry in the array. The debug message at the end of the > > > function then dereferences this pointer: > > > > > > pr_debug("Failed to hot-remove memory at %llx\n", > > > lmb->base_addr); > > > > While this is a reasonable fix and the stable material it is really > > unclear to me why it has gained a CVE. Memory hotplug is a privileged > > operation. Could you clarify please? > > As you know, history has shown us that accessing out of your allocated > memory can cause problems, and we can not assume use-cases, as we don't > know how everyone uses our codebase, so marking places where we fix > out-of-bound memory accesses is resolving a weakness in the codebase, > hence a CVE assignment. Does that mean that any potentially incorrect input provided by an admin is considered CVE now? I guess we would need to ban interfaces like /dev/mem and many others. > If your systems are not vulnerable to this specific issue, wonderful, no > need to take it, but why wouldn't you want to take a fix that resolves a > known weakness? I have explicitly said, the fix is reasonable. I just do not see a point to mark it as CVE. I fail to see any thread model where this would matter as it would require untrusted privileged actor to trigger it AFAICS. I am happy to be proven wrong here. -- Michal Hocko SUSE Labs