From: Wei Yang <richard.weiyang@xxxxxxxxx> Subject: mm/memblock.c: check return value of memblock_reserve() in memblock_virt_alloc_internal() memblock_reserve() would add a new range to memblock.reserved in case the new range is not totally covered by any of the current memblock.reserved range. If the memblock.reserved is full and can't resize, memblock_reserve() would fail. This doesn't happen in real world now, I observed this during code review. While theoretically, it has the chance to happen. And if it happens, others would think this range of memory is still available and may corrupt the memory. This patch checks the return value and goto "done" after it succeeds. Link: http://lkml.kernel.org/r/1482363033-24754-3-git-send-email-richard.weiyang@xxxxxxxxx Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memblock.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff -puN mm/memblock.c~mm-memblockc-check-return-value-of-memblock_reserve-in-memblock_virt_alloc_internal mm/memblock.c --- a/mm/memblock.c~mm-memblockc-check-return-value-of-memblock_reserve-in-memblock_virt_alloc_internal +++ a/mm/memblock.c @@ -1299,18 +1299,17 @@ static void * __init memblock_virt_alloc if (max_addr > memblock.current_limit) max_addr = memblock.current_limit; - again: alloc = memblock_find_in_range_node(size, align, min_addr, max_addr, nid, flags); - if (alloc) + if (alloc && !memblock_reserve(alloc, size)) goto done; if (nid != NUMA_NO_NODE) { alloc = memblock_find_in_range_node(size, align, min_addr, max_addr, NUMA_NO_NODE, flags); - if (alloc) + if (alloc && !memblock_reserve(alloc, size)) goto done; } @@ -1328,7 +1327,6 @@ again: return NULL; done: - memblock_reserve(alloc, size); ptr = phys_to_virt(alloc); memset(ptr, 0, size); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
