From 19eeb2f9e750f47c805f66e3b0e889b12557d80f Mon Sep 17 00:00:00 2001 From: Alexey Khoroshilov Date: Thu, 10 Jul 2014 18:43:01 -0400 Subject: [PATCH] farsync: fix invalid memory accesses in fst_add_one() and fst_init_card() There are several issues in fst_add_one() and fst_init_card(): - invalid pointer dereference at card->ports[card->nports - 1] if register_hdlc_device() fails for the first port in fst_init_card(); - fst_card_array overflow at fst_card_array[no_of_cards_added] because there is no checks for array overflow; - use after free because pointer to deallocated card is left in fst_card_array if something fails after fst_card_array[no_of_cards_added] = card; - several leaks on failure paths in fst_add_one(). The patch fixes all the issues and makes code more readable. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov Signed-off-by: David S. Miller --- drivers/net/wan/farsync.c | 112 ++++++++++++++++++++------------------ 1 file changed, 58 insertions(+), 54 deletions(-) diff --git a/drivers/net/wan/farsync.c b/drivers/net/wan/farsync.c index 93ace042d0aa..1f041271f7fe 100644 --- a/drivers/net/wan/farsync.c +++ b/drivers/net/wan/farsync.c @@ -2363,7 +2363,7 @@ static char *type_strings[] = { "FarSync TE1" }; -static void +static int fst_init_card(struct fst_card_info *card) { int i; @@ -2374,24 +2374,21 @@ fst_init_card(struct fst_card_info *card) * we'll have to revise it in some way then. */ for (i = 0; i < card->nports; i++) { - err = register_hdlc_device(card->ports[i].dev); - if (err < 0) { - int j; + err = register_hdlc_device(card->ports[i].dev); + if (err < 0) { pr_err("Cannot register HDLC device for port %d (errno %d)\n", - i, -err); - for (j = i; j < card->nports; j++) { - free_netdev(card->ports[j].dev); - card->ports[j].dev = NULL; - } - card->nports = i; - break; - } + i, -err); + while (i--) + unregister_hdlc_device(card->ports[i].dev); + return err; + } } pr_info("%s-%s: %s IRQ%d, %d ports\n", port_to_dev(&card->ports[0])->name, port_to_dev(&card->ports[card->nports - 1])->name, type_strings[card->type], card->irq, card->nports); + return 0; } static const struct net_device_ops fst_ops = { @@ -2447,15 +2444,12 @@ fst_add_one(struct pci_dev *pdev, const struct pci_device_id *ent) /* Try to enable the device */ if ((err = pci_enable_device(pdev)) != 0) { pr_err("Failed to enable card. Err %d\n", -err); - kfree(card); - return err; + goto enable_fail; } if ((err = pci_request_regions(pdev, "FarSync")) !=0) { pr_err("Failed to allocate regions. Err %d\n", -err); - pci_disable_device(pdev); - kfree(card); - return err; + goto regions_fail; } /* Get virtual addresses of memory regions */ @@ -2464,30 +2458,21 @@ fst_add_one(struct pci_dev *pdev, const struct pci_device_id *ent) card->phys_ctlmem = pci_resource_start(pdev, 3); if ((card->mem = ioremap(card->phys_mem, FST_MEMSIZE)) == NULL) { pr_err("Physical memory remap failed\n"); - pci_release_regions(pdev); - pci_disable_device(pdev); - kfree(card); - return -ENODEV; + err = -ENODEV; + goto ioremap_physmem_fail; } if ((card->ctlmem = ioremap(card->phys_ctlmem, 0x10)) == NULL) { pr_err("Control memory remap failed\n"); - pci_release_regions(pdev); - pci_disable_device(pdev); - iounmap(card->mem); - kfree(card); - return -ENODEV; + err = -ENODEV; + goto ioremap_ctlmem_fail; } dbg(DBG_PCI, "kernel mem %p, ctlmem %p\n", card->mem, card->ctlmem); /* Register the interrupt handler */ if (request_irq(pdev->irq, fst_intr, IRQF_SHARED, FST_DEV_NAME, card)) { pr_err("Unable to register interrupt %d\n", card->irq); - pci_release_regions(pdev); - pci_disable_device(pdev); - iounmap(card->ctlmem); - iounmap(card->mem); - kfree(card); - return -ENODEV; + err = -ENODEV; + goto irq_fail; } /* Record info we need */ @@ -2513,13 +2498,8 @@ fst_add_one(struct pci_dev *pdev, const struct pci_device_id *ent) while (i--) free_netdev(card->ports[i].dev); pr_err("FarSync: out of memory\n"); - free_irq(card->irq, card); - pci_release_regions(pdev); - pci_disable_device(pdev); - iounmap(card->ctlmem); - iounmap(card->mem); - kfree(card); - return -ENODEV; + err = -ENOMEM; + goto hdlcdev_fail; } card->ports[i].dev = dev; card->ports[i].card = card; @@ -2565,9 +2545,16 @@ fst_add_one(struct pci_dev *pdev, const struct pci_device_id *ent) pci_set_drvdata(pdev, card); /* Remainder of card setup */ + if (no_of_cards_added >= FST_MAX_CARDS) { + pr_err("FarSync: too many cards\n"); + err = -ENOMEM; + goto card_array_fail; + } fst_card_array[no_of_cards_added] = card; card->card_no = no_of_cards_added++; /* Record instance and bump it */ - fst_init_card(card); + err = fst_init_card(card); + if (err) + goto init_card_fail; if (card->family == FST_FAMILY_TXU) { /* * Allocate a dma buffer for transmit and receives @@ -2577,29 +2564,46 @@ fst_add_one(struct pci_dev *pdev, const struct pci_device_id *ent) &card->rx_dma_handle_card); if (card->rx_dma_handle_host == NULL) { pr_err("Could not allocate rx dma buffer\n"); - fst_disable_intr(card); - pci_release_regions(pdev); - pci_disable_device(pdev); - iounmap(card->ctlmem); - iounmap(card->mem); - kfree(card); - return -ENOMEM; + err = -ENOMEM; + goto rx_dma_fail; } card->tx_dma_handle_host = pci_alloc_consistent(card->device, FST_MAX_MTU, &card->tx_dma_handle_card); if (card->tx_dma_handle_host == NULL) { pr_err("Could not allocate tx dma buffer\n"); - fst_disable_intr(card); - pci_release_regions(pdev); - pci_disable_device(pdev); - iounmap(card->ctlmem); - iounmap(card->mem); - kfree(card); - return -ENOMEM; + err = -ENOMEM; + goto tx_dma_fail; } } return 0; /* Success */ + +tx_dma_fail: + pci_free_consistent(card->device, FST_MAX_MTU, + card->rx_dma_handle_host, + card->rx_dma_handle_card); +rx_dma_fail: + fst_disable_intr(card); + for (i = 0 ; i < card->nports ; i++) + unregister_hdlc_device(card->ports[i].dev); +init_card_fail: + fst_card_array[card->card_no] = NULL; +card_array_fail: + for (i = 0 ; i < card->nports ; i++) + free_netdev(card->ports[i].dev); +hdlcdev_fail: + free_irq(card->irq, card); +irq_fail: + iounmap(card->ctlmem); +ioremap_ctlmem_fail: + iounmap(card->mem); +ioremap_physmem_fail: + pci_release_regions(pdev); +regions_fail: + pci_disable_device(pdev); +enable_fail: + kfree(card); + return err; } /* -- 2.20.1