From 0ee4acb7b3bedfe264aabe4a7c47762e2cbdc97c Mon Sep 17 00:00:00 2001 From: Milton Miller Date: Thu, 29 Sep 2016 13:24:08 -0300 Subject: [PATCH] tg3: Avoid NULL pointer dereference in tg3_io_error_detected() [ Upstream commit 1b0ff89852d79354e8a091c81a88df21f5aa9f0a ] While the driver is probing the adapter, an error may occur before the netdev structure is allocated and attached to pci_dev. In this case, not only netdev isn't available, but the tg3 private structure is also not available as it is just math from the NULL pointer, so dereferences must be skipped. The following trace is seen when the error is triggered: [1.402247] Unable to handle kernel paging request for data at address 0x00001a99 [1.402410] Faulting instruction address: 0xc0000000007e33f8 [1.402450] Oops: Kernel access of bad area, sig: 11 [#1] [1.402481] SMP NR_CPUS=2048 NUMA PowerNV [1.402513] Modules linked in: [1.402545] CPU: 0 PID: 651 Comm: eehd Not tainted 4.4.0-36-generic #55-Ubuntu [1.402591] task: c000001fe4e42a20 ti: c000001fe4e88000 task.ti: c000001fe4e88000 [1.402742] NIP: c0000000007e33f8 LR: c0000000007e3164 CTR: c000000000595ea0 [1.402787] REGS: c000001fe4e8b790 TRAP: 0300 Not tainted (4.4.0-36-generic) [1.402832] MSR: 9000000100009033 CR: 28000422 XER: 20000000 [1.403058] CFAR: c000000000008468 DAR: 0000000000001a99 DSISR: 42000000 SOFTE: 1 GPR00: c0000000007e3164 c000001fe4e8ba10 c0000000015c5e00 0000000000000000 GPR04: 0000000000000001 0000000000000000 0000000000000039 0000000000000299 GPR08: 0000000000000000 0000000000000001 c000001fe4e88000 0000000000000006 GPR12: 0000000000000000 c00000000fb40000 c0000000000e6558 c000003ca1bffd00 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 c000000000d52768 GPR24: c000000000d52740 0000000000000100 c000003ca1b52000 0000000000000002 GPR28: 0000000000000900 0000000000000000 c00000000152a0c0 c000003ca1b52000 [1.404226] NIP [c0000000007e33f8] tg3_io_error_detected+0x308/0x340 [1.404265] LR [c0000000007e3164] tg3_io_error_detected+0x74/0x340 This patch avoids the NULL pointer dereference by moving the access after the netdev NULL pointer check on tg3_io_error_detected(). Also, we add a check for netdev being NULL on tg3_io_resume() [suggested by Michael Chan]. Fixes: 0486a063b1ff ("tg3: prevent ifup/ifdown during PCI error recovery") Fixes: dfc8f370316b ("net/tg3: Release IRQs on permanent error") Tested-by: Guilherme G. Piccoli Signed-off-by: Milton Miller Signed-off-by: Guilherme G. Piccoli Acked-by: Michael Chan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/broadcom/tg3.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index ca5ac5d6f4e6..49056c33be74 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -18142,14 +18142,14 @@ static pci_ers_result_t tg3_io_error_detected(struct pci_dev *pdev, rtnl_lock(); - /* We needn't recover from permanent error */ - if (state == pci_channel_io_frozen) - tp->pcierr_recovery = true; - /* We probably don't have netdev yet */ if (!netdev || !netif_running(netdev)) goto done; + /* We needn't recover from permanent error */ + if (state == pci_channel_io_frozen) + tp->pcierr_recovery = true; + tg3_phy_stop(tp); tg3_netif_stop(tp); @@ -18246,7 +18246,7 @@ static void tg3_io_resume(struct pci_dev *pdev) rtnl_lock(); - if (!netif_running(netdev)) + if (!netdev || !netif_running(netdev)) goto done; tg3_full_lock(tp, 0); -- 2.20.1