On Sat, 2020-07-18 at 10:45 +0800, Macpaul Lin wrote:

From: Eddie Hung <redacted>

Well, it's strange, I simply replaced the uploader's name to my
colleague, git send-email pop up this line automatically.

Shouldn't I do that kind of change. It did not happened before.
Do I need to change it back and update patch v3?
 

There is a use-after-free issue, if access udc_name
in function gadget_dev_desc_UDC_store after another context
free udc_name in function unregister_gadget.

Context 1:
gadget_dev_desc_UDC_store()->unregister_gadget()->
free udc_name->set udc_name to NULL

Context 2:
gadget_dev_desc_UDC_show()-> access udc_name

Call trace:
dump_backtrace+0x0/0x340
show_stack+0x14/0x1c
dump_stack+0xe4/0x134
print_address_description+0x78/0x478
__kasan_report+0x270/0x2ec
kasan_report+0x10/0x18
__asan_report_load1_noabort+0x18/0x20
string+0xf4/0x138
vsnprintf+0x428/0x14d0
sprintf+0xe4/0x12c
gadget_dev_desc_UDC_show+0x54/0x64
configfs_read_file+0x210/0x3a0
__vfs_read+0xf0/0x49c
vfs_read+0x130/0x2b4
SyS_read+0x114/0x208
el0_svc_naked+0x34/0x38

Add mutex_lock to protect this kind of scenario.

Signed-off-by: Eddie Hung <redacted>
Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Reviewed-by: Peter Chen <redacted>
Cc: stable@vger.kernel.org
---
Changes for v2:
  - Fix typo %s/contex/context, Thanks Peter.

 drivers/usb/gadget/configfs.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

Thanks.
Macpaul Lin

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