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/misc/vexpress-syscfg.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/misc') diff --git a/drivers/misc/vexpress-syscfg.c b/drivers/misc/vexpress-syscfg.c index 9eea30f..80a6f19 100644 --- a/drivers/misc/vexpress-syscfg.c +++ b/drivers/misc/vexpress-syscfg.c @@ -182,8 +182,7 @@ static struct regmap *vexpress_syscfg_regmap_init(struct device *dev, val = energy_quirk; } - func = kzalloc(sizeof(*func) + sizeof(*func->template) * num, - GFP_KERNEL); + func = kzalloc(struct_size(func, template, num), GFP_KERNEL); if (!func) return ERR_PTR(-ENOMEM); -- cgit v1.1 From 0ed2dd03b94b7b7f66e23f25073b5385d0416589 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 8 May 2018 16:08:53 -0700 Subject: treewide: Use struct_size() for devm_kmalloc() and friends Replaces open-coded struct size calculations with struct_size() for devm_*, f2fs_*, and sock_* allocations. Automatically generated (and manually adjusted) from the following Coccinelle script: // Direct reference to struct field. @@ identifier alloc =~ "devm_kmalloc|devm_kzalloc|sock_kmalloc|f2fs_kmalloc|f2fs_kzalloc"; expression HANDLE; expression GFP; identifier VAR, ELEMENT; expression COUNT; @@ - alloc(HANDLE, sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP) + alloc(HANDLE, struct_size(VAR, ELEMENT, COUNT), GFP) // mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL); @@ identifier alloc =~ "devm_kmalloc|devm_kzalloc|sock_kmalloc|f2fs_kmalloc|f2fs_kzalloc"; expression HANDLE; expression GFP; identifier VAR, ELEMENT; expression COUNT; @@ - alloc(HANDLE, sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP) + alloc(HANDLE, struct_size(VAR, ELEMENT, COUNT), GFP) // Same pattern, but can't trivially locate the trailing element name, // or variable name. @@ identifier alloc =~ "devm_kmalloc|devm_kzalloc|sock_kmalloc|f2fs_kmalloc|f2fs_kzalloc"; expression HANDLE; expression GFP; expression SOMETHING, COUNT, ELEMENT; @@ - alloc(HANDLE, sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP) + alloc(HANDLE, CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP) Signed-off-by: Kees Cook --- drivers/misc/cb710/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/misc') diff --git a/drivers/misc/cb710/core.c b/drivers/misc/cb710/core.c index fb397e7..4d4acf7 100644 --- a/drivers/misc/cb710/core.c +++ b/drivers/misc/cb710/core.c @@ -232,8 +232,8 @@ static int cb710_probe(struct pci_dev *pdev, if (val & CB710_SLOT_SM) ++n; - chip = devm_kzalloc(&pdev->dev, - sizeof(*chip) + n * sizeof(*chip->slot), GFP_KERNEL); + chip = devm_kzalloc(&pdev->dev, struct_size(chip, slot, n), + GFP_KERNEL); if (!chip) return -ENOMEM; -- cgit v1.1