| Message ID | 20220327223625.134198-1-jeremy@azazel.net |
|---|---|
| State | Accepted |
| Delegated to: | Pablo Neira |
| Headers | show |
| Series | [nf,v2] netfilter: bitwise: fix reduce comparisons | expand |
On Sun, Mar 27, 2022 at 11:36:25PM +0100, Jeremy Sowden wrote: > The `nft_bitwise_reduce` and `nft_bitwise_fast_reduce` functions should > compare the bitwise operation in `expr` with the tracked operation > associated with the destination register of `expr`. However, instead of > being called on `expr` and `track->regs[priv->dreg].selector`, > `nft_expr_priv` is called on `expr` twice, so both reduce functions > return true even when the operations differ. Good catch, applied thanks
diff --git a/net/netfilter/nft_bitwise.c b/net/netfilter/nft_bitwise.c index 7b727d3ebf9d..04bd2f89afe8 100644 --- a/net/netfilter/nft_bitwise.c +++ b/net/netfilter/nft_bitwise.c @@ -287,7 +287,7 @@ static bool nft_bitwise_reduce(struct nft_regs_track *track, if (!track->regs[priv->sreg].selector) return false; - bitwise = nft_expr_priv(expr); + bitwise = nft_expr_priv(track->regs[priv->dreg].selector); if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector && track->regs[priv->dreg].bitwise && track->regs[priv->dreg].bitwise->ops == expr->ops && @@ -434,7 +434,7 @@ static bool nft_bitwise_fast_reduce(struct nft_regs_track *track, if (!track->regs[priv->sreg].selector) return false; - bitwise = nft_expr_priv(expr); + bitwise = nft_expr_priv(track->regs[priv->dreg].selector); if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector && track->regs[priv->dreg].bitwise && track->regs[priv->dreg].bitwise->ops == expr->ops &&
The `nft_bitwise_reduce` and `nft_bitwise_fast_reduce` functions should compare the bitwise operation in `expr` with the tracked operation associated with the destination register of `expr`. However, instead of being called on `expr` and `track->regs[priv->dreg].selector`, `nft_expr_priv` is called on `expr` twice, so both reduce functions return true even when the operations differ. Fixes: be5650f8f47e ("netfilter: nft_bitwise: track register operations") Signed-off-by: Jeremy Sowden <jeremy@azazel.net> --- Since v1: * fix `nft_bitwise_fast_reduce` as well as `nft_bitwise_reduce`. net/netfilter/nft_bitwise.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)