Re: [Xen-devel] [PATCH for-4.9 v3 3/3] xen/livepatch: Don't crash on encountering STN_UNDEF relocations

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

On Thu, Jun 22, 2017 at 07:15:29PM +0100, Andrew Cooper wrote:
> A symndx of STN_UNDEF is special, and means a symbol value of 0.  While
> legitimate in the ELF standard, its existance in a livepatch is questionable
> at best.  Until a plausible usecase presents itself, reject such a relocation
> with -EOPNOTSUPP.
> 
> Additionally, fix an off-by-one error while range checking symndx, and perform
> a safety check on elf->sym[symndx].sym before derefencing it, to avoid
> tripping over a NULL pointer when calculating val.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> ---
> CC: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> [arm32 and x86]

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel