Re: BUG: drivers/usb/host/xhci: memleak in alloc from xhci_disable_usb3_lpm_timeout()

[Mirsad Goran Todorovac]

On 25. 03. 2023. 12:27, Mirsad Goran Todorovac wrote:
> Hi all!
> 
> Here are again the good news and the bad news:
> 
> BAD:  another kernel memory leak detected (one more to hunt down and fix)
> GOOD: another kernel memory leak detected (one less unaccounted for)
> 
> I tried to make some fun, but maintainers are busy folks, so let's get down
> to business:
> 
> ---
> Nine (9) new systemd-udevd kernel memory leaks occurred (unable to reproduce).
> 
> The platform is Ubuntu 22.10 with (relatively recent) systemd 251.4-1ubuntu7.1
> on LENOVO_MT_82H8_BU_idea_FM_IdeaPad 3 15ITL6 with BIOS GGCN51WW from 11/16/2022.
> 
> The symptom (/sys/kernel/debug/kmemleak output):
> 
> unreferenced object 0xffff909698ff9280 (size 64):
>   comm "systemd-udevd", pid 436, jiffies 4294893239 (age 6287.088s)
>   hex dump (first 32 bytes):
>     e0 51 bb 99 96 90 ff ff 00 00 00 00 00 00 00 00  .Q..............
>     40 5b bb 99 96 90 ff ff 00 00 00 00 00 00 00 00  @[..............
>   backtrace:
>     [<ffffffffb29de94c>] slab_post_alloc_hook+0x8c/0x320
>     [<ffffffffb29e5107>] __kmem_cache_alloc_node+0x1c7/0x2b0
>     [<ffffffffb2962f3b>] kmalloc_node_trace+0x2b/0xa0
>     [<ffffffffb31af2ec>] xhci_alloc_command+0x7c/0x1b0
>     [<ffffffffb31af451>] xhci_alloc_command_with_ctx+0x21/0x70
>     [<ffffffffb31a8a3e>] xhci_change_max_exit_latency+0x2e/0x1c0
>     [<ffffffffb31a8c5b>] xhci_disable_usb3_lpm_timeout+0x7b/0xb0
>     [<ffffffffb31457a7>] usb_disable_link_state+0x57/0xe0
>     [<ffffffffb3145f46>] usb_disable_lpm+0x86/0xc0
>     [<ffffffffb3145fc1>] usb_unlocked_disable_lpm+0x31/0x60
>     [<ffffffffb3155db6>] usb_disable_device+0x136/0x250
>     [<ffffffffb3156b23>] usb_set_configuration+0x583/0xa70
>     [<ffffffffb3164c6d>] usb_generic_driver_disconnect+0x2d/0x40
>     [<ffffffffb3158612>] usb_unbind_device+0x32/0x90
>     [<ffffffffb3022295>] device_remove+0x65/0x70
>     [<ffffffffb3023903>] device_release_driver_internal+0xc3/0x140
> unreferenced object 0xffff909699bb5b40 (size 32):
>   comm "systemd-udevd", pid 436, jiffies 4294893239 (age 6287.088s)
>   hex dump (first 32 bytes):
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>     50 5b bb 99 96 90 ff ff 50 5b bb 99 96 90 ff ff  P[......P[......
>   backtrace:
>     [<ffffffffb29de94c>] slab_post_alloc_hook+0x8c/0x320
>     [<ffffffffb29e5107>] __kmem_cache_alloc_node+0x1c7/0x2b0
>     [<ffffffffb2962f3b>] kmalloc_node_trace+0x2b/0xa0
>     [<ffffffffb31af364>] xhci_alloc_command+0xf4/0x1b0
>     [<ffffffffb31af451>] xhci_alloc_command_with_ctx+0x21/0x70
>     [<ffffffffb31a8a3e>] xhci_change_max_exit_latency+0x2e/0x1c0
>     [<ffffffffb31a8c5b>] xhci_disable_usb3_lpm_timeout+0x7b/0xb0
>     [<ffffffffb31457a7>] usb_disable_link_state+0x57/0xe0
>     [<ffffffffb3145f46>] usb_disable_lpm+0x86/0xc0
>     [<ffffffffb3145fc1>] usb_unlocked_disable_lpm+0x31/0x60
>     [<ffffffffb3155db6>] usb_disable_device+0x136/0x250
>     [<ffffffffb3156b23>] usb_set_configuration+0x583/0xa70
>     [<ffffffffb3164c6d>] usb_generic_driver_disconnect+0x2d/0x40
>     [<ffffffffb3158612>] usb_unbind_device+0x32/0x90
>     [<ffffffffb3022295>] device_remove+0x65/0x70
>     [<ffffffffb3023903>] device_release_driver_internal+0xc3/0x140
> unreferenced object 0xffff909699bb51e0 (size 32):
>   comm "systemd-udevd", pid 436, jiffies 4294893239 (age 6287.088s)
>   hex dump (first 32 bytes):
>     02 00 00 00 20 04 00 00 00 a0 ff 98 96 90 ff ff  .... ...........
>     00 a0 ff 18 01 00 00 00 00 00 00 00 00 00 00 00  ................
>   backtrace:
>     [<ffffffffb29de94c>] slab_post_alloc_hook+0x8c/0x320
>     [<ffffffffb29e5107>] __kmem_cache_alloc_node+0x1c7/0x2b0
>     [<ffffffffb2962f3b>] kmalloc_node_trace+0x2b/0xa0
>     [<ffffffffb31ad86e>] xhci_alloc_container_ctx+0x7e/0x140
>     [<ffffffffb31af469>] xhci_alloc_command_with_ctx+0x39/0x70
>     [<ffffffffb31a8a3e>] xhci_change_max_exit_latency+0x2e/0x1c0
>     [<ffffffffb31a8c5b>] xhci_disable_usb3_lpm_timeout+0x7b/0xb0
>     [<ffffffffb31457a7>] usb_disable_link_state+0x57/0xe0
>     [<ffffffffb3145f46>] usb_disable_lpm+0x86/0xc0
>     [<ffffffffb3145fc1>] usb_unlocked_disable_lpm+0x31/0x60
>     [<ffffffffb3155db6>] usb_disable_device+0x136/0x250
>     [<ffffffffb3156b23>] usb_set_configuration+0x583/0xa70
>     [<ffffffffb3164c6d>] usb_generic_driver_disconnect+0x2d/0x40
>     [<ffffffffb3158612>] usb_unbind_device+0x32/0x90
>     [<ffffffffb3022295>] device_remove+0x65/0x70
>     [<ffffffffb3023903>] device_release_driver_internal+0xc3/0x140
> .
> .
> .
> 
> Please find the config, lshw output and complete /sys/kernel/debug/kmemleak
> output here:
> 
> https://domac.alu.unizg.hr/~mtodorov/linux/bugreports/systemd-udevd/kmemleak.log
> 
> https://domac.alu.unizg.hr/~mtodorov/linux/bugreports/systemd-udevd/lshw.txt
> https://domac.alu.unizg.hr/~mtodorov/linux/bugreports/systemd-udevd/config-6.3.0-rc3-kobj-rlse-00317-g65aca32efdcb
> 
> The systemd issue tracker said they accept issues only for the most recent 253 and
> 252, 251.4 seems too old for them despite being issued on May 21, 2022
> (Source: https://github.com/systemd/systemd/releases).
> 
> It is not that I want to dump this on Linux kernel developers, but I felt
> like it is a kernel memory leak problem rather than a bug in systemd-udevd.
> 
> Of course, my hunch might be wrong ...
> 
> As per Code of Conduct, I have checked for the developers and maintainers with
> scripts/get_maintainers.pl.

By the Murphy's Law, it appears that I forgot the most impotant thing:
the kernel is 6.3-rc+ commit 65aca32efdcb from Torvalds tree, with
KMEMLEAK, CONFIG_DEBUG_{KOBJECT|KOBJECT_RELEASE} enabled.

Have a nice day.

-- 
Mirsad Goran Todorovac
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu
 
System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb, Republic of Croatia
The European Union