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Date: Tue, 16 Sep 1997 20:33:05 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199709161033.UAA28695@godzilla.zeta.org.au>
To: bde@FreeBSD.ORG, cvs-all@FreeBSD.ORG, cvs-committers@FreeBSD.ORG,
        cvs-sys@FreeBSD.ORG
Subject: Re: cvs commit: src/sys/kern subr_diskslice.c
Sender: owner-cvs-sys@FreeBSD.ORG
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>bde         1997/09/16 03:11:54 PDT
>
>  Modified files:
>    sys/kern             subr_diskslice.c 
>  Log:
>  Reject attempts to set an in-core label which says that the "disk"
>  or a partition is larger than the slice.
>  
>  Now `disklabel -Brw sdX auto' should fail properly on sliced disks
>  without partition of type 165, e.g., on zip disks with the factory
>  default formatting.  Previously it set a bogus in-core label for
>  the compatibility slice and used this to corrupt the MBR (the slice
>  has offset 0 and size 0, but setting the label in effect corrupted
>  its size to nonzero).
>  
>  `disklabel -Brw sdX auto' already failed properly on normally (not
>  dangerously dedicated) sliced disks _with_ partition of type 165,
>  because the compatibility slice has a nonzero offset so the MBR
>  remained inaccessible when the size was corrupted.
>  
>  This bug only affected in-core labels.  On-disk labels are checked
>  carefully when they read and written.
>  
>  Revision  Changes    Path
>  1.38      +10 -4     src/sys/kern/subr_diskslice.c

This should go in all stable versions (after testing of course).

Bruce