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authorSrinivas Kandagatla <srinivas.kandagatla@linaro.org>2018-06-04 15:14:08 +0100
committerRob Herring <robh@kernel.org>2018-06-04 09:46:57 -0600
commit522811e944ed9b36806faa019faec10f9d259cca (patch)
treeff112979655937aa29b28aa8f2530d00c6891c12 /drivers/of
parent7824b54dd72ddd1f1d26aa48604b7ea17cfaebc3 (diff)
downloadlinux-522811e944ed9b36806faa019faec10f9d259cca.tar.bz2
of: platform: stop accessing invalid dev in of_platform_device_destroy
Immediately after the platform_device_unregister() the device will be cleaned up. Accessing the freed pointer immediately after that will crash the system. Found this bug when kernel is built with CONFIG_PAGE_POISONING and testing loading/unloading audio drivers in a loop on Qcom platforms. Fix this by moving of_node_clear_flag() just before the unregister calls. Below is the crash trace: Unable to handle kernel paging request at virtual address 6b6b6b6b6b6c03 Mem abort info: ESR = 0x96000021 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000021 CM = 0, WnR = 0 [006b6b6b6b6b6c03] address between user and kernel address ranges Internal error: Oops: 96000021 [#1] PREEMPT SMP Modules linked in: CPU: 2 PID: 1784 Comm: sh Tainted: G W 4.17.0-rc7-02230-ge3a63a7ef641-dirty #204 Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) pstate: 80000005 (Nzcv daif -PAN -UAO) pc : clear_bit+0x18/0x2c lr : of_platform_device_destroy+0x64/0xb8 sp : ffff00000c9c3930 x29: ffff00000c9c3930 x28: ffff80003d39b200 x27: ffff000008bb1000 x26: 0000000000000040 x25: 0000000000000124 x24: ffff80003a9a3080 x23: 0000000000000060 x22: ffff00000939f518 x21: ffff80003aa79e98 x20: ffff80003aa3dae0 x19: ffff80003aa3c890 x18: ffff800009feb794 x17: 0000000000000000 x16: 0000000000000000 x15: ffff800009feb790 x14: 0000000000000000 x13: ffff80003a058778 x12: ffff80003a058728 x11: ffff80003a058750 x10: 0000000000000000 x9 : 0000000000000006 x8 : ffff80003a825988 x7 : bbbbbbbbbbbbbbbb x6 : 0000000000000001 x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000008 x2 : 0000000000000001 x1 : 6b6b6b6b6b6b6c03 x0 : 0000000000000000 Process sh (pid: 1784, stack limit = 0x (ptrval)) Call trace: clear_bit+0x18/0x2c q6afe_remove+0x20/0x38 apr_device_remove+0x30/0x70 device_release_driver_internal+0x170/0x208 device_release_driver+0x14/0x20 bus_remove_device+0xcc/0x150 device_del+0x10c/0x310 device_unregister+0x1c/0x70 apr_remove_device+0xc/0x18 device_for_each_child+0x50/0x80 apr_remove+0x18/0x20 rpmsg_dev_remove+0x38/0x68 device_release_driver_internal+0x170/0x208 device_release_driver+0x14/0x20 bus_remove_device+0xcc/0x150 device_del+0x10c/0x310 device_unregister+0x1c/0x70 qcom_smd_remove_device+0xc/0x18 device_for_each_child+0x50/0x80 qcom_smd_unregister_edge+0x3c/0x70 smd_subdev_remove+0x18/0x28 rproc_stop+0x48/0xd8 rproc_shutdown+0x60/0xe8 state_store+0xbc/0xf8 dev_attr_store+0x18/0x28 sysfs_kf_write+0x3c/0x50 kernfs_fop_write+0x118/0x1e0 __vfs_write+0x18/0x110 vfs_write+0xa4/0x1a8 ksys_write+0x48/0xb0 sys_write+0xc/0x18 el0_svc_naked+0x30/0x34 Code: d2800022 8b400c21 f9800031 9ac32043 (c85f7c22) ---[ end trace 32020935775616a2 ]--- Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Cc: stable@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'drivers/of')
-rw-r--r--drivers/of/platform.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index d75050b85d0c..0b49a62b38a3 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -548,6 +548,9 @@ int of_platform_device_destroy(struct device *dev, void *data)
if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
device_for_each_child(dev, NULL, of_platform_device_destroy);
+ of_node_clear_flag(dev->of_node, OF_POPULATED);
+ of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
+
if (dev->bus == &platform_bus_type)
platform_device_unregister(to_platform_device(dev));
#ifdef CONFIG_ARM_AMBA
@@ -555,8 +558,6 @@ int of_platform_device_destroy(struct device *dev, void *data)
amba_device_unregister(to_amba_device(dev));
#endif
- of_node_clear_flag(dev->of_node, OF_POPULATED);
- of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
return 0;
}
EXPORT_SYMBOL_GPL(of_platform_device_destroy);