From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 50A341494AC; Wed, 27 Mar 2024 14:37:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711550225; cv=none; b=KovbBO1/CgxuyEFIgEVNu1sevMW6ZC30X7iD6nk34hmXiNrHLwzjR61kY9UksyivHv7xfaE84W7JeYSk26vxdVYTj831VvAdAdHBCeu/x4qzvm24jCAW4zPuAG+pg1MX1xojGEI34RwmQ8g1NVHGEjJSwVTZdK5ChgpDZ1mz488= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711550225; c=relaxed/simple; bh=CNvTdSlrwsQbv/udDF8Dk7iqvTn3Y6HeV3CkmDU+yOs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=iWtx4oAF16idl+FGVBu7TauhjBPjzLma4YnRrc707C97yMmZtBVrqSre/chd1B8+lmgjR+oXgxZKgd5ufWRSMcnoL9xhhodNbcIQeQPraAL74UNKDwQaHE40wa3BrXQpZvZtvTdXIOKXWjYNGaSAUgHzIpt+pXZ1LtOozg39P3s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LtEJdsCC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="LtEJdsCC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 867B0C433F1; Wed, 27 Mar 2024 14:37:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1711550225; bh=CNvTdSlrwsQbv/udDF8Dk7iqvTn3Y6HeV3CkmDU+yOs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LtEJdsCCdKpsltsQU6Ytj7X4C265OAerO6/JumdSuySgr+fi/PZIZV6fjzUF4+zj3 eIcOFw82FGggfERd9RGAZd8jPx9PPULtfnL7gW6UVoofpnZOOr3JJ9TmA+n7iSNWrG wxssgc1GiQiEHR+ljTQ8kSPLatxk/4kaZkwbP82s= Date: Wed, 27 Mar 2024 15:37:02 +0100 From: Greg Kroah-Hartman To: Shung-Hsi Yu Cc: linux-cve-announce@vger.kernel.org, cve@kernel.org, linux-kernel@vger.kernel.org Subject: Re: CVE-2023-52462: bpf: fix check for attempt to corrupt spilled pointer Message-ID: <2024032752-crave-emu-c82a@gregkh> References: <2024022335-CVE-2023-52462-b663@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: On Tue, Mar 05, 2024 at 11:41:52PM +0800, Shung-Hsi Yu wrote: > On Fri, Feb 23, 2024 at 03:47:35PM +0100, Greg Kroah-Hartman wrote: > > Description > > =========== > > > > In the Linux kernel, the following vulnerability has been resolved: > > > > bpf: fix check for attempt to corrupt spilled pointer > > > > When register is spilled onto a stack as a 1/2/4-byte register, we set > > slot_type[BPF_REG_SIZE - 1] (plus potentially few more below it, > > depending on actual spill size). So to check if some stack slot has > > spilled register we need to consult slot_type[7], not slot_type[0]. > > > > To avoid the need to remember and double-check this in the future, just > > use is_spilled_reg() helper. > > > > The Linux kernel CVE team has assigned CVE-2023-52462 to this issue. > > > > > > Affected and fixed versions > > =========================== > > > > Issue introduced in 5.10.163 with commit cdd73a5ed084 and fixed in 5.10.209 with commit 2757f17972d8 > > Issue introduced in 5.15.86 with commit 07c286c10a9c and fixed in 5.15.148 with commit 67e6707f0735 > > Issue introduced in 5.16 with commit 27113c59b6d0 and fixed in 6.1.75 with commit fc3e3c50a0a4 > > Issue introduced in 5.16 with commit 27113c59b6d0 and fixed in 6.6.14 with commit 8dc15b067059 > > Issue introduced in 5.16 with commit 27113c59b6d0 and fixed in 6.7.2 with commit 40617d45ea05 > > Issue introduced in 5.16 with commit 27113c59b6d0 and fixed in 6.8-rc1 with commit ab125ed3ec1c > > While commit 27113c59b6d0 ("bpf: Check the other end of slot_type for > STACK_SPILL") is referenced in the Fixes tag, and made the switch to use > slot_type[7] instead of slot_type[0]. This shouldn't cause any issue > because its commit message stated that > > ... Verifier currently only saves the reg state if the whole 8 bytes > are spilled to the stack, so checking the slot_type[7] is the same as > checking slot_type[0]. > > It is the next commit in the series, commit 354e8f1970f8 ("bpf: Support > <8-byte scalar spill and refill"), that rendered checking slot_type[0] > problematic. > > So I believe the issue is introduced with commit 354e8f1970f8 rather > than 27113c59b6d0. That said kernel releases seems to either contain > both or none of them at all, so in pratice the difference probably > doesn't matter too much. Thanks for the information! greg k-h > > > [snip] >