| Message ID | 20180601183144.17374-1-xiyou.wangcong@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Jason Gunthorpe |
| Headers | show |
On Fri, Jun 01, 2018 at 11:31:44AM -0700, Cong Wang wrote: > ucma_process_join() will free the new allocated "mc" struct, > if there is any error after that, especially the copy_to_user(). > > But in parallel, ucma_leave_multicast() could find this "mc" > through idr_find() before ucma_process_join() frees it, since it > is already published. > > So "mc" could be used in ucma_leave_multicast() after it is been > allocated and freed in ucma_process_join(), since we don't refcnt > it. > > Fix this by separating "publish" from ID allocation, so that we > can get an ID first and publish it later after copy_to_user(). > > Fixes c8f6a362bf3e ("RDMA/cma: Add multicast communication support") > Reported-by: Noam Rathaus <noamr@beyondsecurity.com> > Cc: Sean Hefty <sean.hefty@intel.com> > Cc: Doug Ledford <dledford@redhat.com> > Cc: Jason Gunthorpe <jgg@ziepe.ca> > Cc: linux-rdma@vger.kernel.org > Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> > --- > drivers/infiniband/core/ucma.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) Looks good to me, and we already fixed the same sort of bug in the non-multicast IDs.. Applied to for-next Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c index eab43b17e9cf..ec8fb289621f 100644 --- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -235,7 +235,7 @@ static struct ucma_multicast* ucma_alloc_multicast(struct ucma_context *ctx) return NULL; mutex_lock(&mut); - mc->id = idr_alloc(&multicast_idr, mc, 0, 0, GFP_KERNEL); + mc->id = idr_alloc(&multicast_idr, NULL, 0, 0, GFP_KERNEL); mutex_unlock(&mut); if (mc->id < 0) goto error; @@ -1421,6 +1421,10 @@ static ssize_t ucma_process_join(struct ucma_file *file, goto err3; } + mutex_lock(&mut); + idr_replace(&multicast_idr, mc, mc->id); + mutex_unlock(&mut); + mutex_unlock(&file->mut); ucma_put_ctx(ctx); return 0;
ucma_process_join() will free the new allocated "mc" struct, if there is any error after that, especially the copy_to_user(). But in parallel, ucma_leave_multicast() could find this "mc" through idr_find() before ucma_process_join() frees it, since it is already published. So "mc" could be used in ucma_leave_multicast() after it is been allocated and freed in ucma_process_join(), since we don't refcnt it. Fix this by separating "publish" from ID allocation, so that we can get an ID first and publish it later after copy_to_user(). Fixes c8f6a362bf3e ("RDMA/cma: Add multicast communication support") Reported-by: Noam Rathaus <noamr@beyondsecurity.com> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Doug Ledford <dledford@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: linux-rdma@vger.kernel.org Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> --- drivers/infiniband/core/ucma.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)