Messages in this thread | | | Date | Wed, 18 Jun 2014 09:35:55 +0100 | From | Matt Fleming <> | Subject | Re: [PATCH] pstore: Fix an overflow on 32-bit builds. |
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On Mon, 09 Jun, at 01:24:43PM, David Rientjes wrote: > On Mon, 9 Jun 2014, Andrzej Zaborowski wrote: > > > [resend] > > In generic_id the long int timestamp is multiplied by 100000 and needs > > an explicit cast to u64. > > > > Without that the id in the resulting pstore filename is wrong and > > userspace may have problems parsing it, but more importantly files in > > pstore can never be deleted and may fill the EFI flash (brick device?). > > This happens because when generic pstore code wants to delete a file, > > it passes the id to the EFI backend which reinterpretes it and a wrong > > variable name is attempted to be deleted. There's no error message but > > after remounting pstore, deleted files would reappear.
It shouldn't be possible to brick devices because the efi-pstore code still goes through efivar_entry_set_safe() whic has the necessary checks. Please let me know if you've witnessed any fallout from this bug other than being unable to delete files.
> This fixes commit fdeadb43fdf1 ("efi-pstore: Make efi-pstore return a > unique id") that went into stable, so I'm not sure if this should go into > stable as well.
I think it should go to stable too. Tony?
> You probably had to resend this because you didn't email any of the > maintainers (fixed). Use scripts/get_maintainer.pl to figure out who to > email about a patch.
Thanks for triaging this David.
Unless anyone speaks up I'm going to throw this into the EFI tree with David's Acked-by.
-- Matt Fleming, Intel Open Source Technology Center
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