Commit a5544880 authored by Luis R. Rodriguez's avatar Luis R. Rodriguez Committed by Jessica Yu

module: fix memory leak on early load_module() failures

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.

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@vger.kernel.org> # v2.6.30
Fixes: e180a6b7 ("param: fix charp parameters set via sysfs")
Reviewed-by: default avatarMiroslav Benes <mbenes@suse.cz>
Reviewed-by: default avatarAaron Tomlin <atomlin@redhat.com>
Reviewed-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarLuis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: default avatarJessica Yu <jeyu@redhat.com>
parent 5ff22646
...@@ -3724,6 +3724,7 @@ static int load_module(struct load_info *info, const char __user *uargs, ...@@ -3724,6 +3724,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
mod_sysfs_teardown(mod); mod_sysfs_teardown(mod);
coming_cleanup: coming_cleanup:
mod->state = MODULE_STATE_GOING; mod->state = MODULE_STATE_GOING;
destroy_params(mod->kp, mod->num_kp);
blocking_notifier_call_chain(&module_notify_list, blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod); MODULE_STATE_GOING, mod);
klp_module_going(mod); klp_module_going(mod);
......
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