b839215372
If the addition of the coresight devices get deferred, then there's a window before child_name is populated by of_get_coresight_platform_data from the respective component driver's probe and the attempted to access the same from coresight_orphan_match resulting in kernel NULL pointer dereference as below: Unable to handle kernel NULL pointer dereference at virtual address 0x0 Internal error: Oops: 96000004 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 1038 Comm: kworker/0:1 Not tainted 4.7.0-rc3 #124 Hardware name: ARM Juno development board (r2) (DT) Workqueue: events amba_deferred_retry_func PC is at strcmp+0x1c/0x160 LR is at coresight_orphan_match+0x7c/0xd0 Call trace: strcmp+0x1c/0x160 bus_for_each_dev+0x60/0xa0 coresight_register+0x264/0x2e0 tmc_probe+0x130/0x310 amba_probe+0xd4/0x1c8 driver_probe_device+0x22c/0x418 __device_attach_driver+0xbc/0x158 bus_for_each_drv+0x58/0x98 __device_attach+0xc4/0x160 device_initial_probe+0x10/0x18 bus_probe_device+0x94/0xa0 device_add+0x344/0x580 amba_device_try_add+0x194/0x238 amba_deferred_retry_func+0x48/0xd0 process_one_work+0x118/0x378 worker_thread+0x48/0x498 kthread+0xd0/0xe8 ret_from_fork+0x10/0x40 This patch adds a check for non-NULL conn->child_name before accessing the same. Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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