"Luis R. Rodriguez" <mcgrof@xxxxxxxxxx> writes:
> While looking for early possible module loading failures I was
> able to reproduce a memory leak possible with kmemleak. There
> are a few rare ways to trigger a failure:
>
> o we've run into a failure while processing kernel parameters
> (parse_args() returns an error)
> o mod_sysfs_setup() fails
> o we're a live patch module and copy_module_elf() fails
>
> Chances of running into this issue is really low.
Good catch!
Reviewed-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cheers,
Rusty.
>
> kmemleak splat:
>
> unreferenced object 0xffff9f2c4ada1b00 (size 32):
> comm "kworker/u16:4", pid 82, jiffies 4294897636 (age 681.816s)
> hex dump (first 32 bytes):
> 6d 65 6d 73 74 69 63 6b 30 00 00 00 00 00 00 00 memstick0.......
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> backtrace:
> [<ffffffff8c6cfeba>] kmemleak_alloc+0x4a/0xa0
> [<ffffffff8c200046>] __kmalloc_track_caller+0x126/0x230
> [<ffffffff8c1bc581>] kstrdup+0x31/0x60
> [<ffffffff8c1bc5d4>] kstrdup_const+0x24/0x30
> [<ffffffff8c3c23aa>] kvasprintf_const+0x7a/0x90
> [<ffffffff8c3b5481>] kobject_set_name_vargs+0x21/0x90
> [<ffffffff8c4fbdd7>] dev_set_name+0x47/0x50
> [<ffffffffc07819e5>] memstick_check+0x95/0x33c [memstick]
> [<ffffffff8c09c893>] process_one_work+0x1f3/0x4b0
> [<ffffffff8c09cb98>] worker_thread+0x48/0x4e0
> [<ffffffff8c0a2b79>] kthread+0xc9/0xe0
> [<ffffffff8c6dab5f>] ret_from_fork+0x1f/0x40
> [<ffffffffffffffff>] 0xffffffffffffffff
>
> Cc: stable <stable@xxxxxxxxxxxxxxx> # v2.6.30
> Fixes: e180a6b7759a ("param: fix charp parameters set via sysfs")
> Reviewed-by: Miroslav Benes <mbenes@xxxxxxx>
> Reviewed-by: Aaron Tomlin <atomlin@xxxxxxxxxx>
> Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
> ---
> kernel/module.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/module.c b/kernel/module.c
> index 38d4270925d4..8409a82424d2 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -3722,6 +3722,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
> mod_sysfs_teardown(mod);
> coming_cleanup:
> mod->state = MODULE_STATE_GOING;
> + destroy_params(mod->kp, mod->num_kp);
> blocking_notifier_call_chain(&module_notify_list,
> MODULE_STATE_GOING, mod);
> klp_module_going(mod);
> --
> 2.10.2
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