From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (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 2693855E73; Fri, 24 May 2024 10:02:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716544933; cv=none; b=M7Ks7+6Eq3oeNTcJZBqPicJEZCZ+GPSk4qZtIQVZsIxtwHfV2YgMjEENBbZQ0nhVfZh584fztWzk/NAXeG9qryVlqgF4ozyJHkjGmiaH0/22sZJli/2+S6G1bnL0UxGOJLFdrlFlkrdnllqOwW+S3++HkP3NpwUznZC1g8pTrqc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716544933; c=relaxed/simple; bh=WGWTQ88lZDy9oTdVJgnyIUfB1dQtFV5h7aTFZonsxc0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dEQbCMhmr8wItNhVFbulOVOgn+XsNbpisL9cDHUEoXO/e4KjSXSitTZ0aBHa0dVdhrC8uQvQLUNUS1Sp5o3vu4J6zlWLqPq8mD/lvd6OYPqO+kte6pIb9YFGmdO413+wx95sJMZq78j77yTheNIw0VXu/jiyvppi+4+Uy4Ic43Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz; spf=pass smtp.mailfrom=suse.cz; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b=XhRmepdG; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b=Mm108XQm; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b=XhRmepdG; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b=Mm108XQm; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.cz Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b="XhRmepdG"; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b="Mm108XQm"; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b="XhRmepdG"; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b="Mm108XQm" Received: from localhost (unknown [10.100.12.32]) by smtp-out1.suse.de (Postfix) with ESMTP id 3686D339FD; Fri, 24 May 2024 10:02:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1716544930; 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=m/OEvrzWeGwb1dUHEq64+dHG7ZwZd+5GEDO1Ba+pFW4=; b=XhRmepdGTrrFnqxO+ClvvJHopazd1ctZTY8rYZEh7ZSjX3gtbirDqMCdhsffm3L2f2IbRo 5nLL/RiI/xU3qYdsnvPwOIS5xfSElPEUHP6SQhBiKdgxpOfSBWQHXPZOLvRtWMmX0s6Ink 2TbcJeOeXMaJMy3cohOlYyOgAn22wRw= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1716544930; 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=m/OEvrzWeGwb1dUHEq64+dHG7ZwZd+5GEDO1Ba+pFW4=; b=Mm108XQmAJJG6HE75E4M537VgfCYxaPopdC2tzOKUEioGzeAIg5vJg/J2em9jrR1aKmFO8 V55JzhDyP4Ks1oAQ== Authentication-Results: smtp-out1.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1716544930; 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=m/OEvrzWeGwb1dUHEq64+dHG7ZwZd+5GEDO1Ba+pFW4=; b=XhRmepdGTrrFnqxO+ClvvJHopazd1ctZTY8rYZEh7ZSjX3gtbirDqMCdhsffm3L2f2IbRo 5nLL/RiI/xU3qYdsnvPwOIS5xfSElPEUHP6SQhBiKdgxpOfSBWQHXPZOLvRtWMmX0s6Ink 2TbcJeOeXMaJMy3cohOlYyOgAn22wRw= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1716544930; 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=m/OEvrzWeGwb1dUHEq64+dHG7ZwZd+5GEDO1Ba+pFW4=; b=Mm108XQmAJJG6HE75E4M537VgfCYxaPopdC2tzOKUEioGzeAIg5vJg/J2em9jrR1aKmFO8 V55JzhDyP4Ks1oAQ== Date: Fri, 24 May 2024 12:02:10 +0200 From: Jiri Bohac To: cve@kernel.org, linux-kernel@vger.kernel.org Cc: linux-cve-announce@vger.kernel.org, Greg Kroah-Hartman , Eric Biederman , kexec@lists.infradead.org Subject: Re: CVE-2023-52823: kernel: kexec: copy user-array safely Message-ID: References: <2024052106-CVE-2023-52823-3d81@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: <2024052106-CVE-2023-52823-3d81@gregkh> X-Spam-Level: X-Spamd-Result: default: False [-3.47 / 50.00]; BAYES_HAM(-2.17)[96.01%]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-0.995]; MIME_GOOD(-0.10)[text/plain]; RCVD_COUNT_ZERO(0.00)[0]; MIME_TRACE(0.00)[0:+]; ARC_NA(0.00)[]; MISSING_XM_UA(0.00)[]; MID_RHS_MATCH_FROMTLD(0.00)[]; FROM_HAS_DN(0.00)[]; DKIM_SIGNED(0.00)[suse.cz:s=susede2_rsa,suse.cz:s=susede2_ed25519]; FROM_EQ_ENVFROM(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; RCPT_COUNT_FIVE(0.00)[6] X-Spam-Score: -3.47 X-Spam-Flag: NO On Tue, May 21, 2024 at 05:31:59PM +0200, Greg Kroah-Hartman wrote: > kernel: kexec: copy user-array safely > > Currently, there is no overflow-check with memdup_user(). This is false. Therefore, I'd like to dispute this CVE. The overflow check is in the kexec_load_check() function called shortly before the memdup_user() call: SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, struct kexec_segment __user *, segments, unsigned long, flags) { result = kexec_load_check(nr_segments, flags); if (result) return result; ... ksegments = memdup_user(segments, nr_segments * sizeof(ksegments[0])); ... } #define KEXEC_SEGMENT_MAX 16 static inline int kexec_load_check(unsigned long nr_segments, unsigned long flags) { ... if (nr_segments > KEXEC_SEGMENT_MAX) return -EINVAL; } Thanks, -- Jiri Bohac SUSE Labs, Prague, Czechia