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| author | David Rientjes <rientjes@google.com> | 2009-08-26 14:29:20 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-08-26 20:06:52 -0700 |
| commit | a30b595d2ca6d39e784a1bed5f2b35f3d7a03af7 (patch) | |
| tree | 101d1cdf6088a36a09ad5470a062331a74ab657d /lib | |
| parent | 054b2b13ccba4876a1ce98a7ede7dab7d6893d01 (diff) | |
| download | linux-a30b595d2ca6d39e784a1bed5f2b35f3d7a03af7.tar.bz2 | |
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 <rientjes@google.com>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/flex_array.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/lib/flex_array.c b/lib/flex_array.c index 08f1636d296a..e73c691aec36 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)]; } |