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Date: Tue, 12 Nov 2024 13:12:23 +0100
From: Greg KH <gregkh@linuxfoundation.org>
To: Agathe Porte <agathe.porte@canonical.com>
Cc: linux-kernel@vger.kernel.org, Jeff Johnson <quic_jjohnson@quicinc.com>,
	Andrew Morton <akpm@linux-foundation.org>, stable@vger.kernel.org
Subject: Re: [PATCH v2 1/1] ufs: ufs_sb_private_info: remove unused
 s_{2,3}apb fields
Message-ID: <2024111251-buggy-scarily-38dd@gregkh>
References: <20241112120304.32452-1-agathe.porte@canonical.com>
 <20241112120304.32452-2-agathe.porte@canonical.com>
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In-Reply-To: <20241112120304.32452-2-agathe.porte@canonical.com>

On Tue, Nov 12, 2024 at 01:01:54PM +0100, Agathe Porte wrote:
> These two fields are populated during and stored as a "frequently used
> value" in ufs_fill_super, but are not used afterwards in the driver.
> 
> Moreover, one of the shifts triggers UBSAN: shift-out-of-bounds when
> apbshift is 12 because 12 * 3 = 36 and 1 << 36 does not fit in the 32
> bit integer used to store the value.
> 
> Cc: stable@vger.kernel.org
> Closes: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2087853

As these values are not used, even if the shift goes off in the wild
it's not needed to backport this as it's not actually causing any
problems.  So I'd drop the cc: stable@ please.

thanks,

greg k-h