Re: [syzbot] [usb?] memory leak in class_create

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
memory leak in class_create

BUG: memory leak
unreferenced object 0xffff88810a6af480 (size 96):
  comm "kworker/0:2", pid 1755, jiffies 4294944661 (age 9.520s)
  hex dump (first 32 bytes):
    c7 03 9b 85 ff ff ff ff 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff81544e14>] kmalloc_trace+0x24/0x90 mm/slab_common.c:1057
    [<ffffffff82b65445>] kmalloc include/linux/slab.h:559 [inline]
    [<ffffffff82b65445>] kzalloc include/linux/slab.h:680 [inline]
    [<ffffffff82b65445>] class_create+0x25/0x90 drivers/base/class.c:261
    [<ffffffff831f7a9b>] init_usb_class drivers/usb/core/file.c:91 [inline]
    [<ffffffff831f7a9b>] usb_register_dev+0x2ab/0x3e0 drivers/usb/core/file.c:179
    [<ffffffff832cfff4>] usblp_probe+0x4e4/0x750 drivers/usb/class/usblp.c:1208
    [<ffffffff831f39a9>] usb_probe_interface+0x179/0x3c0 drivers/usb/core/driver.c:396
    [<ffffffff82b62d7d>] call_driver_probe drivers/base/dd.c:579 [inline]
    [<ffffffff82b62d7d>] really_probe+0x12d/0x430 drivers/base/dd.c:658
    [<ffffffff82b63141>] __driver_probe_device+0xc1/0x1a0 drivers/base/dd.c:800
    [<ffffffff82b6324a>] driver_probe_device+0x2a/0x120 drivers/base/dd.c:830
    [<ffffffff82b6343b>] __device_attach_driver+0xfb/0x150 drivers/base/dd.c:958
    [<ffffffff82b60191>] bus_for_each_drv+0xc1/0x110 drivers/base/bus.c:457
    [<ffffffff82b63962>] __device_attach+0x102/0x2a0 drivers/base/dd.c:1030
    [<ffffffff82b618fa>] bus_probe_device+0xca/0xd0 drivers/base/bus.c:532
    [<ffffffff82b5def3>] device_add+0x993/0xc60 drivers/base/core.c:3625
    [<ffffffff831f0a89>] usb_set_configuration+0x9a9/0xc90 drivers/usb/core/message.c:2211
    [<ffffffff832033d1>] usb_generic_driver_probe+0xa1/0x100 drivers/usb/core/generic.c:238
    [<ffffffff831f3080>] usb_probe_device+0x60/0x140 drivers/usb/core/driver.c:293

BUG: memory leak
unreferenced object 0xffff888114088c00 (size 512):
  comm "kworker/0:2", pid 1755, jiffies 4294944661 (age 9.520s)
  hex dump (first 32 bytes):
    00 8c 08 14 81 88 ff ff 00 8c 08 14 81 88 ff ff  ................
    00 00 00 00 00 00 00 00 c7 03 9b 85 ff ff ff ff  ................
  backtrace:
    [<ffffffff81544e14>] kmalloc_trace+0x24/0x90 mm/slab_common.c:1057
    [<ffffffff82b65308>] kmalloc include/linux/slab.h:559 [inline]
    [<ffffffff82b65308>] kzalloc include/linux/slab.h:680 [inline]
    [<ffffffff82b65308>] class_register+0x28/0x140 drivers/base/class.c:186
    [<ffffffff82b65467>] class_create+0x47/0x90 drivers/base/class.c:270
    [<ffffffff831f7a9b>] init_usb_class drivers/usb/core/file.c:91 [inline]
    [<ffffffff831f7a9b>] usb_register_dev+0x2ab/0x3e0 drivers/usb/core/file.c:179
    [<ffffffff832cfff4>] usblp_probe+0x4e4/0x750 drivers/usb/class/usblp.c:1208
    [<ffffffff831f39a9>] usb_probe_interface+0x179/0x3c0 drivers/usb/core/driver.c:396
    [<ffffffff82b62d7d>] call_driver_probe drivers/base/dd.c:579 [inline]
    [<ffffffff82b62d7d>] really_probe+0x12d/0x430 drivers/base/dd.c:658
    [<ffffffff82b63141>] __driver_probe_device+0xc1/0x1a0 drivers/base/dd.c:800
    [<ffffffff82b6324a>] driver_probe_device+0x2a/0x120 drivers/base/dd.c:830
    [<ffffffff82b6343b>] __device_attach_driver+0xfb/0x150 drivers/base/dd.c:958
    [<ffffffff82b60191>] bus_for_each_drv+0xc1/0x110 drivers/base/bus.c:457
    [<ffffffff82b63962>] __device_attach+0x102/0x2a0 drivers/base/dd.c:1030
    [<ffffffff82b618fa>] bus_probe_device+0xca/0xd0 drivers/base/bus.c:532
    [<ffffffff82b5def3>] device_add+0x993/0xc60 drivers/base/core.c:3625
    [<ffffffff831f0a89>] usb_set_configuration+0x9a9/0xc90 drivers/usb/core/message.c:2211
    [<ffffffff832033d1>] usb_generic_driver_probe+0xa1/0x100 drivers/usb/core/generic.c:238



Tested on:

commit:         22b8cc3e Merge tag 'x86_mm_for_6.4' of git://git.kerne..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
console output: https://syzkaller.appspot.com/x/log.txt?x=14569d94280000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5046ebeca744dd40
dashboard link: https://syzkaller.appspot.com/bug?extid=e7afd76ad060fa0d2605
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch:          https://syzkaller.appspot.com/x/patch.diff?x=138259d7c80000