| Message ID | 20210113053810.13518-1-gilad.reti@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [bpf,v2,1/2] bpf: support PTR_TO_MEM{,_OR_NULL} register spilling | expand |
On 1/12/21 9:38 PM, Gilad Reti wrote: > Add a test to check that the verifier is able to recognize spilling of > PTR_TO_MEM registers, by reserving a ringbuf buffer, forcing the spill > of a pointer holding the buffer address to the stack, filling it back > in from the stack and writing to the memory area pointed by it. > > The patch was partially contributed by CyberArk Software, Inc. > > Signed-off-by: Gilad Reti <gilad.reti@gmail.com> I didn't verify result_unpriv = ACCEPT part. I think it is correct by checking code. Acked-by: Yonghong Song <yhs@fb.com>
On Wed, Jan 13, 2021 at 5:05 PM Yonghong Song <yhs@fb.com> wrote: > > > > On 1/12/21 9:38 PM, Gilad Reti wrote: > > Add a test to check that the verifier is able to recognize spilling of > > PTR_TO_MEM registers, by reserving a ringbuf buffer, forcing the spill > > of a pointer holding the buffer address to the stack, filling it back > > in from the stack and writing to the memory area pointed by it. > > > > The patch was partially contributed by CyberArk Software, Inc. > > > > Signed-off-by: Gilad Reti <gilad.reti@gmail.com> > > I didn't verify result_unpriv = ACCEPT part. I think it is correct > by checking code. > > Acked-by: Yonghong Song <yhs@fb.com> Thanks for the description! Acked-by: KP Singh <kpsingh@kernel.org>
On Wed, Jan 13, 2021 at 6:38 AM Gilad Reti <gilad.reti@gmail.com> wrote: > > Add support for pointer to mem register spilling, to allow the verifier > to track pointers to valid memory addresses. Such pointers are returned > for example by a successful call of the bpf_ringbuf_reserve helper. > > The patch was partially contributed by CyberArk Software, Inc. > > Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") > Suggested-by: Yonghong Song <yhs@fb.com> > Signed-off-by: Gilad Reti <gilad.reti@gmail.com> Acked-by: KP Singh <kpsingh@kernel.org>
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 17270b8404f1..36af69fac591 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -2217,6 +2217,8 @@ static bool is_spillable_regtype(enum bpf_reg_type type) case PTR_TO_RDWR_BUF: case PTR_TO_RDWR_BUF_OR_NULL: case PTR_TO_PERCPU_BTF_ID: + case PTR_TO_MEM: + case PTR_TO_MEM_OR_NULL: return true; default: return false;
Add support for pointer to mem register spilling, to allow the verifier to track pointers to valid memory addresses. Such pointers are returned for example by a successful call of the bpf_ringbuf_reserve helper. The patch was partially contributed by CyberArk Software, Inc. Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") Suggested-by: Yonghong Song <yhs@fb.com> Signed-off-by: Gilad Reti <gilad.reti@gmail.com> --- kernel/bpf/verifier.c | 2 ++ 1 file changed, 2 insertions(+)