From eb82fbcf82965c18da11ada92b82f1400b36e0ad Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Sat, 21 Jan 2017 08:04:45 +0300 Subject: [PATCH] orangefs: silence harmless integer overflow warning The issue here is that in orangefs_bufmap_alloc() we do: bufmap->buffer_index_array = kzalloc(DIV_ROUND_UP(bufmap->desc_count, BITS_PER_LONG), GFP_KERNEL); If we choose a bufmap->desc_count like -31 then it means the DIV_ROUND_UP ends up having an integer overflow. The result is that kzalloc() returns the ZERO_SIZE_PTR and there is a static checker warning. But this bug is harmless because on the next lines we use ->desc_count to do a kcalloc(). That has integer overflow checking built in so the kcalloc() fails and we return an error code. Anyway, it doesn't make sense to talk about negative sizes and blocking them silences the static checker warning. Signed-off-by: Dan Carpenter Signed-off-by: Mike Marshall --- fs/orangefs/orangefs-bufmap.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/orangefs/orangefs-bufmap.c b/fs/orangefs/orangefs-bufmap.c index 75375e90a63f..6333cbbdfef7 100644 --- a/fs/orangefs/orangefs-bufmap.c +++ b/fs/orangefs/orangefs-bufmap.c @@ -344,6 +344,11 @@ int orangefs_bufmap_initialize(struct ORANGEFS_dev_map_desc *user_desc) user_desc->size, user_desc->count); + if (user_desc->total_size < 0 || + user_desc->size < 0 || + user_desc->count < 0) + goto out; + /* * sanity check alignment and size of buffer that caller wants to * work with -- 2.20.1