On Thu, Sep 29, 2016 at 9:24 AM, Guilherme G. Piccoli
<gpicc...@linux.vnet.ibm.com> wrote:
> From: Milton Miller <milt...@us.ibm.com>
>
> 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 <SF,HV,EE,ME,IR,DR,RI,LE> 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 <gpicc...@linux.vnet.ibm.com>
> Signed-off-by: Milton Miller <milt...@us.ibm.com>
> Signed-off-by: Guilherme G. Piccoli <gpicc...@linux.vnet.ibm.com>
Acked-by: Michael Chan <michael.c...@broadcom.com>
