On Fri, Oct 22, 2021 at 3:36 AM Yang Yingliang [off-list ref] wrote:

I got memory leak as follows when doing fault injection test:

unreferenced object 0xffff888020a7a680 (size 64):
  comm "i2c-mcp23018-41", pid 23090, jiffies 4295160544 (age 8.680s)
  hex dump (first 32 bytes):
    00 48 d3 1e 80 88 ff ff 00 1a 56 c1 ff ff ff ff  .H........V.....
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<0000000083c79b35>] kmem_cache_alloc_trace+0x16d/0x360
    [<0000000051803c95>] pinctrl_init_controller+0x6ed/0xb70
    [<0000000064346707>] pinctrl_register+0x27/0x80
    [<0000000029b0e186>] devm_pinctrl_register+0x5b/0xe0
    [<00000000391f5a3e>] mcp23s08_probe_one+0x968/0x118a [pinctrl_mcp23s08]
    [<000000006112c039>] mcp230xx_probe+0x266/0x560 [pinctrl_mcp23s08_i2c]

If pinctrl_claim_hogs() fails, the 'pindesc' allocated in pinctrl_register_one_pin()
need be freed.

Reported-by: Hulk Robot <redacted>
Fixes: 950b0d91dc10 ("pinctrl: core: Fix regression caused by delayed work for hogs")
Signed-off-by: Yang Yingliang <redacted>

Excellent find and fix!

Thanks so much Yang!

Patch applied and tagged for stable.

Yours,
Linus Walleij