Re: [PATCH 1/3] net: ethernet: bcmasp: fix possible OOB write in bcmasp_netfilt_get_all_active()
From: Paolo Abeni <pabeni@redhat.com>
Date: 2023-09-07 18:13:21
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linux-arm-kernel, linux-mediatek, lkml
On Wed, 2023-09-06 at 17:21 +0800, Hangyu Hua wrote:
quoted hunk ↗ jump to hunk
rule_locs is allocated in ethtool_get_rxnfc and the size is determined by rule_cnt from user space. So rule_cnt needs to be check before using rule_locs to avoid OOB writing or NULL pointer dereference. Fixes: c5d511c49587 ("net: bcmasp: Add support for wake on net filters") Signed-off-by: Hangyu Hua <redacted> --- drivers/net/ethernet/broadcom/asp2/bcmasp.c | 3 +++ 1 file changed, 3 insertions(+)diff --git a/drivers/net/ethernet/broadcom/asp2/bcmasp.c b/drivers/net/ethernet/broadcom/asp2/bcmasp.c index d63d321f3e7b..4df2ca871af8 100644 --- a/drivers/net/ethernet/broadcom/asp2/bcmasp.c +++ b/drivers/net/ethernet/broadcom/asp2/bcmasp.c@@ -535,6 +535,9 @@ void bcmasp_netfilt_get_all_active(struct bcmasp_intf *intf, u32 *rule_locs, int j = 0, i; for (i = 0; i < NUM_NET_FILTERS; i++) { + if (j == *rule_cnt) + break;
Side note: it's a bit unfortunate/confusing that the drivers can arbitrary return -EMSGSIZE or silently truncate the list. I think it would be clearer if we could stick to single behavior - and I'll vote for -EMSGSIZE. Cheers, Paolo