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| author | Sudeep Holla <sudeep.holla@arm.com> | 2016-08-25 15:18:51 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-31 13:05:42 +0200 |
| commit | b8392153721c83de4e5d47ee455bbfefd0c8259e (patch) | |
| tree | dfa811b1fbf79b68b38091c31d1439a83763ee55 /drivers/hwtracing | |
| parent | b605c2d913589c448d4a6887262bb8e99da12009 (diff) | |
| download | linux-b8392153721c83de4e5d47ee455bbfefd0c8259e.tar.gz linux-b8392153721c83de4e5d47ee455bbfefd0c8259e.tar.bz2 linux-b8392153721c83de4e5d47ee455bbfefd0c8259e.zip | |
coresight: access conn->child_name only if it's initialised
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>
Diffstat (limited to 'drivers/hwtracing')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index d08d1ab9bba5..ceeaaea41ed6 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -725,7 +725,8 @@ static int coresight_orphan_match(struct device *dev, void *data) /* We have found at least one orphan connection */ if (conn->child_dev == NULL) { /* Does it match this newly added device? */ - if (!strcmp(dev_name(&csdev->dev), conn->child_name)) { + if (conn->child_name && + !strcmp(dev_name(&csdev->dev), conn->child_name)) { conn->child_dev = csdev; } else { /* This component still has an orphan */ |