On Wed, Jun 10, 2020 at 09:51:11PM +0100, Russell King wrote: > When using ip_set with counters and comment, traffic causes the kernel > to panic on 32-bit ARM: > > Alignment trap: not handling instruction e1b82f9f at [<bf01b0dc>] > Unhandled fault: alignment exception (0x221) at 0xea08133c > PC is at ip_set_match_extensions+0xe0/0x224 [ip_set] > > The problem occurs when we try to update the 64-bit counters - the > faulting address above is not 64-bit aligned. The problem occurs > due to the way elements are allocated, for example: > > set->dsize = ip_set_elem_len(set, tb, 0, 0); > map = ip_set_alloc(sizeof(*map) + elements * set->dsize); > > If the element has a requirement for a member to be 64-bit aligned, > and set->dsize is not a multiple of 8, but is a multiple of four, > then every odd numbered elements will be misaligned - and hitting > an atomic64_add() on that element will cause the kernel to panic. > > ip_set_elem_len() must return a size that is rounded to the maximum > alignment of any extension field stored in the element. This change > ensures that is the case. Applied, thanks.
