From 20fe935358de5f3481790f3e3d399cf97801f830 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 14 Jun 2018 15:27:27 -0700 Subject: exofs: avoid VLA in structures On the quest to remove all VLAs from the kernel[1] this adjusts several cases where allocation is made after an array of structures that points back into the allocation. The allocations are changed to perform explicit calculations instead of using a Variable Length Array in a structure. Additionally, this lets Clang compile this code now, since Clang does not support VLAIS[2]. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com [2] https://lkml.kernel.org/r/CA+55aFy6h1c3_rP_bXFedsTXzwW+9Q9MfJaW7GUmMBrAp-fJ9A@mail.gmail.com [keescook@chromium.org: v2] Link: http://lkml.kernel.org/r/20180418163546.GA45794@beast Link: http://lkml.kernel.org/r/20180327203904.GA1151@beast Signed-off-by: Kees Cook Reviewed-by: Nick Desaulniers Cc: Boaz Harrosh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/exofs/super.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) (limited to 'fs/exofs/super.c') diff --git a/fs/exofs/super.c b/fs/exofs/super.c index 719a3152da80..41cf2fbee50d 100644 --- a/fs/exofs/super.c +++ b/fs/exofs/super.c @@ -549,27 +549,26 @@ static int exofs_devs_2_odi(struct exofs_dt_device_info *dt_dev, static int __alloc_dev_table(struct exofs_sb_info *sbi, unsigned numdevs, struct exofs_dev **peds) { - struct __alloc_ore_devs_and_exofs_devs { - /* Twice bigger table: See exofs_init_comps() and comment at - * exofs_read_lookup_dev_table() - */ - struct ore_dev *oreds[numdevs * 2 - 1]; - struct exofs_dev eds[numdevs]; - } *aoded; + /* Twice bigger table: See exofs_init_comps() and comment at + * exofs_read_lookup_dev_table() + */ + const size_t numores = numdevs * 2 - 1; struct exofs_dev *eds; unsigned i; - aoded = kzalloc(sizeof(*aoded), GFP_KERNEL); - if (unlikely(!aoded)) { + sbi->oc.ods = kzalloc(numores * sizeof(struct ore_dev *) + + numdevs * sizeof(struct exofs_dev), GFP_KERNEL); + if (unlikely(!sbi->oc.ods)) { EXOFS_ERR("ERROR: failed allocating Device array[%d]\n", numdevs); return -ENOMEM; } - sbi->oc.ods = aoded->oreds; - *peds = eds = aoded->eds; + /* Start of allocated struct exofs_dev entries */ + *peds = eds = (void *)sbi->oc.ods[numores]; + /* Initialize pointers into struct exofs_dev */ for (i = 0; i < numdevs; ++i) - aoded->oreds[i] = &eds[i].ored; + sbi->oc.ods[i] = &eds[i].ored; return 0; } -- cgit v1.2.3