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Groups > linux.kernel > #1491481
| From | Alexei Starovoitov <alexei.starovoitov@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v3] bpf: Set register type according to is_valid_access() |
| Date | 2016-09-26 20:00 +0200 |
| Message-ID | <slIm5-6Ps-3@gated-at.bofh.it> (permalink) |
| References | <skZyG-4ic-1@gated-at.bofh.it> <slFod-52M-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Mon, Sep 26, 2016 at 04:49:17PM +0200, Daniel Borkmann wrote: > On 09/24/2016 08:01 PM, Mickaël Salaün wrote: > >This prevent future potential pointer leaks when an unprivileged eBPF > >program will read a pointer value from its context. Even if > >is_valid_access() returns a pointer type, the eBPF verifier replace it > >with UNKNOWN_VALUE. The register value that contains a kernel address is > >then allowed to leak. Moreover, this fix allows unprivileged eBPF > >programs to use functions with (legitimate) pointer arguments. > > > >Not an issue currently since reg_type is only set for PTR_TO_PACKET or > >PTR_TO_PACKET_END in XDP and TC programs that can only be loaded as > >privileged. For now, the only unprivileged eBPF program allowed is for > >socket filtering and all the types from its context are UNKNOWN_VALUE. > >However, this fix is important for future unprivileged eBPF programs > >which could use pointers in their context. > > > >Signed-off-by: Mickaël Salaün <mic@digikod.net> > >Cc: Alexei Starovoitov <ast@kernel.org> > >Cc: Daniel Borkmann <daniel@iogearbox.net> > > Seems okay to me: > > Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Mickael, please mention [PATCH net-next] in subject next time. Thanks
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[PATCH v3] bpf: Set register type according to is_valid_access() Mickaël Salaün <mic@digikod.net> - 2016-09-24 20:10 +0200
Re: [PATCH v3] bpf: Set register type according to is_valid_access() Daniel Borkmann <daniel@iogearbox.net> - 2016-09-26 16:50 +0200
Re: [PATCH v3] bpf: Set register type according to is_valid_access() Alexei Starovoitov <alexei.starovoitov@gmail.com> - 2016-09-26 20:00 +0200
Re: [PATCH v3] bpf: Set register type according to is_valid_access() David Miller <davem@davemloft.net> - 2016-09-27 10:00 +0200
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