On 10/1/23 13:07, Christophe JAILLET wrote: > Prepare for the coming implementation by GCC and Clang of the __counted_by > attribute. Flexible array members annotated with __counted_by can have > their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS > (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> > --- > This patch is part of a work done in parallel of what is currently worked > on by Kees Cook. > > My patches are only related to corner cases that do NOT match the > semantic of his Coccinelle script[1]. > > In this case, in tbl_mask_array_alloc(), several things are allocated with > a single allocation. Then, some pointer arithmetic computes the address of > the memory after the flex-array. > > [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci > --- > net/openvswitch/flow_table.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/openvswitch/flow_table.h b/net/openvswitch/flow_table.h > index 9e659db78c05..8d9e83b4d62c 100644 > --- a/net/openvswitch/flow_table.h > +++ b/net/openvswitch/flow_table.h > @@ -48,7 +48,7 @@ struct mask_array { > int count, max; > struct mask_array_stats __percpu *masks_usage_stats; > u64 *masks_usage_zero_cntr; > - struct sw_flow_mask __rcu *masks[]; > + struct sw_flow_mask __rcu *masks[] __counted_by(size); Did you mean 'max'? There is no 'size' in the structure. Also, the patch subject is messed up a bit. Best regards, Ilya Maximets.
