Re: [Qemu-devel] [PATCH] sd: Fix out-of-bounds assertions

[Markus Armbruster <armbru@redhat.com>]

Lidong Chen <lidong.chen@oracle.com> writes:

> Due to an off-by-one error, the assert statements allow an
> out-of-bounds array access.
>
> Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
> ---
>  hw/sd/sd.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/sd/sd.c b/hw/sd/sd.c
> index aaab15f..818f86c 100644
> --- a/hw/sd/sd.c
> +++ b/hw/sd/sd.c
> @@ -144,7 +144,7 @@ static const char *sd_state_name(enum SDCardStates state)
>      if (state == sd_inactive_state) {
>          return "inactive";
>      }
> -    assert(state <= ARRAY_SIZE(state_name));
> +    assert(state < ARRAY_SIZE(state_name));
>      return state_name[state];
>  }
>  
> @@ -165,7 +165,7 @@ static const char *sd_response_name(sd_rsp_type_t rsp)
>      if (rsp == sd_r1b) {
>          rsp = sd_r1;
>      }
> -    assert(rsp <= ARRAY_SIZE(response_name));
> +    assert(rsp < ARRAY_SIZE(response_name));
>      return response_name[rsp];
>  }

This is the second fix for this bug pattern in a fortnight.  Where's
one, there are more:

$ git-grep '<= ARRAY_SIZE'
hw/intc/arm_gicv3_cpuif.c:    assert(aprmax <= ARRAY_SIZE(cs->ich_apr[0]));
hw/intc/arm_gicv3_cpuif.c:    assert(aprmax <= ARRAY_SIZE(cs->ich_apr[0]));
hw/net/stellaris_enet.c:        if (s->tx_fifo_len + 4 <= ARRAY_SIZE(s->tx_fifo)) {
hw/sd/pxa2xx_mmci.c:        && s->tx_len <= ARRAY_SIZE(s->tx_fifo)
hw/sd/pxa2xx_mmci.c:        && s->rx_len <= ARRAY_SIZE(s->rx_fifo)
hw/sd/pxa2xx_mmci.c:        && s->resp_len <= ARRAY_SIZE(s->resp_fifo);
hw/sd/sd.c:    assert(state <= ARRAY_SIZE(state_name));
hw/sd/sd.c:    assert(rsp <= ARRAY_SIZE(response_name));
hw/usb/hcd-xhci.c:    assert(n <= ARRAY_SIZE(tmp));
target/mips/op_helper.c:    if (base_reglist > 0 && base_reglist <= ARRAY_SIZE (multiple_regs)) {
target/mips/op_helper.c:    if (base_reglist > 0 && base_reglist <= ARRAY_SIZE (multiple_regs)) {
target/mips/op_helper.c:    if (base_reglist > 0 && base_reglist <= ARRAY_SIZE (multiple_regs)) {
target/mips/op_helper.c:    if (base_reglist > 0 && base_reglist <= ARRAY_SIZE (multiple_regs)) {
target/ppc/kvm.c:           <= ARRAY_SIZE(hw_debug_points));
target/ppc/kvm.c:           <= ARRAY_SIZE(hw_debug_points));
target/ppc/kvm.c:    assert((nb_hw_breakpoint + nb_hw_watchpoint) <= ARRAY_SIZE(dbg->arch.bp));
tcg/tcg.c:    tcg_debug_assert(pi <= ARRAY_SIZE(op->args));
util/main-loop.c:    g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
util/module.c:    assert(n_dirs <= ARRAY_SIZE(dirs));

Lidong Chen, would you like to have a look at these?

Cc'ing maintainers to help with further investigation.