From: Roland Dreier Date: Tue, 10 Jun 2008 19:29:49 +0000 (-0700) Subject: RDMA/nes: Fix off-by-one in nes_reg_user_mr() error path X-Git-Tag: v2.6.26-rc7~15^2~1 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=24797a344293601f14f49e2d259c3ca447c4f802;p=linux-2.6 RDMA/nes: Fix off-by-one in nes_reg_user_mr() error path nes_reg_user_mr() should fail if page_count becomes >= 1024 * 512 rather than just testing for strict >, because page_count is essentially used as an index into an array with 1024 * 512 entries, so allowing the loop to continue with page_count == 1024 * 512 means that memory after the end of the array is corrupted. This leads to a crash triggerable by a userspace application that requests registration of a too-big region. Also get rid of the call to pci_free_consistent() here to avoid corrupting state with a double free, since the same memory will be freed in the code jumped to at reg_user_mr_err. Signed-off-by: Roland Dreier --- diff --git a/drivers/infiniband/hw/nes/nes_verbs.c b/drivers/infiniband/hw/nes/nes_verbs.c index 99b3c4ae86..d617da9bd3 100644 --- a/drivers/infiniband/hw/nes/nes_verbs.c +++ b/drivers/infiniband/hw/nes/nes_verbs.c @@ -2456,10 +2456,8 @@ static struct ib_mr *nes_reg_user_mr(struct ib_pd *pd, u64 start, u64 length, if ((page_count!=0)&&(page_count<<12)-(region->offset&(4096-1))>=region->length) goto enough_pages; if ((page_count&0x01FF) == 0) { - if (page_count>(1024*512)) { + if (page_count >= 1024 * 512) { ib_umem_release(region); - pci_free_consistent(nesdev->pcidev, 4096, vpbl.pbl_vbase, - vpbl.pbl_pbase); nes_free_resource(nesadapter, nesadapter->allocated_mrs, stag_index); kfree(nesmr);