18.11.2022 01:20, coverity-bot пишет:
Coverity reported the following:
*** CID 1527352: Memory - illegal accesses (OVERRUN)
mm/zblock.c:320 in zblock_alloc()
314 }
315 list = &(pool->block_lists[block_type]);
316
317 check:
318 spin_lock(&list->lock);
319 /* check if there are free slots in cache */
vvv CID 1527352: Memory - illegal accesses (OVERRUN)
vvv Overrunning array of 10208 bytes at byte offset 10208 by dereferencing pointer "list".
320 block = cache_find_block(list);
321 if (block)
322 goto found;
323 spin_unlock(&list->lock);
324
325 /* not found block with free slots try to allocate new empty block */
If this is a false positive, please let us know so we can mark it as
such, or teach the Coverity rules to be smarter. If not, please make
sure fixes get into linux-next. :) For patches fixing this, please
include these lines (but double-check the "Fixes" first):
Reported-by: coverity-bot <keescook+coverity-bot@xxxxxxxxxxxx>
Addresses-Coverity-ID: 1527352 ("Memory - illegal accesses")
Fixes: 9097e28c25c8 ("mm: add zblock - new allocator for use via zpool API")
It looks like block_type is not checked to be < ARRAY_SIZE(block_desc)
after exiting the earlier loop, so the access through "list" may be past
the end of pool->block_lists.
There is no need for this check because it is guaranteed that this code
will be executed only if size <= PAGE_SIZE. Since slot_size for the last
list even exceeds PAGE_SIZE, block_type will be always valid.
