diff options
| author | Doug Ledford <dledford@redhat.com> | 2018-09-21 11:30:13 -0400 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2018-09-25 15:19:06 -0600 |
| commit | c6ce580716372d71cd119bacf73f14a62e9af2ea (patch) | |
| tree | cfec93bc6ebd1580a7498589c05db2d516078b19 | |
| parent | 3312d1c6bdee6aa912c099c0ac0662d197c52842 (diff) | |
RDMA/umem: Fix potential addition overflow
Given a large enough memory allocation, it is possible to wrap the
pinned_vm counter. Check for addition overflow to prevent such
eventualities.
Fixes: 40ddacf2dda9 ("RDMA/umem: Don't hold mmap_sem for too long")
Reported-by: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| -rw-r--r-- | drivers/infiniband/core/umem.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 1886d7709911..8da1cf29a69f 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -85,6 +85,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, struct page **page_list; struct vm_area_struct **vma_list; unsigned long lock_limit; + unsigned long new_pinned; unsigned long cur_base; struct mm_struct *mm; unsigned long npages; @@ -160,12 +161,13 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; down_write(&mm->mmap_sem); - mm->pinned_vm += npages; - if ((mm->pinned_vm > lock_limit) && !capable(CAP_IPC_LOCK)) { + if (check_add_overflow(mm->pinned_vm, npages, &new_pinned) || + (new_pinned > lock_limit && !capable(CAP_IPC_LOCK))) { up_write(&mm->mmap_sem); ret = -ENOMEM; - goto vma; + goto out; } + mm->pinned_vm = new_pinned; up_write(&mm->mmap_sem); cur_base = addr & PAGE_MASK; |