From acafe7e30216166a17e6e226aadc3ecb63993242 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 8 May 2018 13:45:50 -0700 Subject: treewide: Use struct_size() for kmalloc()-family One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct foo { int stuff; void *entry[]; }; instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL); This patch makes the changes for kmalloc()-family (and kvmalloc()-family) uses. It was done via automatic conversion with manual review for the "CHECKME" non-standard cases noted below, using the following Coccinelle script: // pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len * // sizeof *pkey_cache->table, GFP_KERNEL); @@ identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc"; expression GFP; identifier VAR, ELEMENT; expression COUNT; @@ - alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP) + alloc(struct_size(VAR, ELEMENT, COUNT), GFP) // mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL); @@ identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc"; expression GFP; identifier VAR, ELEMENT; expression COUNT; @@ - alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP) + alloc(struct_size(VAR, ELEMENT, COUNT), GFP) // Same pattern, but can't trivially locate the trailing element name, // or variable name. @@ identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc"; expression GFP; expression SOMETHING, COUNT, ELEMENT; @@ - alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP) + alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP) Signed-off-by: Kees Cook --- drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c | 5 ++--- drivers/net/wireless/mediatek/mt76/agg-rx.c | 3 +-- 2 files changed, 3 insertions(+), 5 deletions(-) (limited to 'drivers/net/wireless') diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c index 90f8c89ea59c..9b2e1cb58e38 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c @@ -2987,9 +2987,8 @@ static int iwl_mvm_mac_set_key(struct ieee80211_hw *hw, mvmsta = iwl_mvm_sta_from_mac80211(sta); WARN_ON(rcu_access_pointer(mvmsta->ptk_pn[keyidx])); - ptk_pn = kzalloc(sizeof(*ptk_pn) + - mvm->trans->num_rx_queues * - sizeof(ptk_pn->q[0]), + ptk_pn = kzalloc(struct_size(ptk_pn, q, + mvm->trans->num_rx_queues), GFP_KERNEL); if (!ptk_pn) { ret = -ENOMEM; diff --git a/drivers/net/wireless/mediatek/mt76/agg-rx.c b/drivers/net/wireless/mediatek/mt76/agg-rx.c index fcb208d1f276..89c7d8c7eb48 100644 --- a/drivers/net/wireless/mediatek/mt76/agg-rx.c +++ b/drivers/net/wireless/mediatek/mt76/agg-rx.c @@ -236,8 +236,7 @@ int mt76_rx_aggr_start(struct mt76_dev *dev, struct mt76_wcid *wcid, u8 tidno, mt76_rx_aggr_stop(dev, wcid, tidno); - tid = kzalloc(sizeof(*tid) + size * sizeof(tid->reorder_buf[0]), - GFP_KERNEL); + tid = kzalloc(struct_size(tid, reorder_buf, size), GFP_KERNEL); if (!tid) return -ENOMEM; -- cgit v1.2.3