From a30b595d2ca6d39e784a1bed5f2b35f3d7a03af7 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Wed, 26 Aug 2009 14:29:20 -0700 Subject: [PATCH] flex_array: fix get function for elements in base starting at non-zero If all array elements fit into the base structure and data is copied using flex_array_put() starting at a non-zero index, flex_array_get() will fail to return the data. This fixes the bug by only checking for NULL parts when all elements do not fit in the base structure when flex_array_get() is used. Otherwise, fa_element_to_part_nr() will always be 0 since there are no parts structures needed and such element may never have been put. Thus, it will remain NULL due to the kzalloc() of the base. Additionally, flex_array_put() now only checks for a NULL part when all elements do not fit in the base structure. This is otherwise unnecessary since the base structure is guaranteed to exist (or we would have already hit a NULL pointer). Signed-off-by: David Rientjes Acked-by: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/flex_array.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/lib/flex_array.c b/lib/flex_array.c index 08f1636d296..e73c691aec3 100644 --- a/lib/flex_array.c +++ b/lib/flex_array.c @@ -198,10 +198,11 @@ int flex_array_put(struct flex_array *fa, int element_nr, void *src, gfp_t flags return -ENOSPC; if (elements_fit_in_base(fa)) part = (struct flex_array_part *)&fa->parts[0]; - else + else { part = __fa_get_part(fa, part_nr, flags); - if (!part) - return -ENOMEM; + if (!part) + return -ENOMEM; + } dst = &part->elements[index_inside_part(fa, element_nr)]; memcpy(dst, src, fa->element_size); return 0; @@ -257,11 +258,12 @@ void *flex_array_get(struct flex_array *fa, int element_nr) if (element_nr >= fa->total_nr_elements) return NULL; - if (!fa->parts[part_nr]) - return NULL; if (elements_fit_in_base(fa)) part = (struct flex_array_part *)&fa->parts[0]; - else + else { part = fa->parts[part_nr]; + if (!part) + return NULL; + } return &part->elements[index_inside_part(fa, element_nr)]; }