[dpdk-dev] [PATCH] malloc: fix finding maximum contiguous IOVA size
Yongseok Koh
yskoh at mellanox.com
Wed Dec 12 12:10:54 CET 2018
malloc_elem_find_max_iova_contig() could return invalid size due to a
missing sanity check. The following gdb output shows how 'cur_size' can be
invalid in find_biggest_element().
(gdb) p/x cur_size
$4 = 0xffffffffffe42900
(gdb) p elem
$1 = (struct malloc_elem *) 0x12e842000
(gdb) p *elem
$2 = {heap = 0x7ffff7ff387c, prev = 0x12e831fc0, next =
0x12e842900, free_list = {le_next = 0x109538000, le_prev =
0x7ffff7ff3894}, msl = 0x7ffff7ff107c, state = ELEM_FREE,
pad = 0, size = 2304}
(gdb) p *elem->msl
$5 = {{base_va = 0x100200000, addr_64 = 4297064448}, page_sz =
2097152, socket_id = 0, version = 790, len = 17179869184,
external = 0, memseg_arr = {name = "memseg-2048k-0-0",
'\000' <repeats 47 times>, count = 493, len = 8192, elt_sz
= 48, data = 0x10002e000, rwlock = {cnt = 0}}}
Fixes: 9fe6bceafd51 ("malloc: add finding biggest free IOVA-contiguous element")
Cc: stable at dpdk.org
Cc: anatoly.burakov at intel.com
Signed-off-by: Yongseok Koh <yskoh at mellanox.com>
---
lib/librte_eal/common/malloc_elem.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/lib/librte_eal/common/malloc_elem.c b/lib/librte_eal/common/malloc_elem.c
index 9d3dcb6a9e..052aeeb7be 100644
--- a/lib/librte_eal/common/malloc_elem.c
+++ b/lib/librte_eal/common/malloc_elem.c
@@ -38,6 +38,10 @@ malloc_elem_find_max_iova_contig(struct malloc_elem *elem, size_t align)
/* segment must start after header and with specified alignment */
contig_seg_start = RTE_PTR_ALIGN_CEIL(data_start, align);
+ /* return if aligned address is already out of malloc element */
+ if (contig_seg_start > data_end)
+ return 0;
+
/* if we're in IOVA as VA mode, or if we're in legacy mode with
* hugepages, all elements are IOVA-contiguous. however, we can only
* make these assumptions about internal memory - externally allocated
--
2.11.0
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