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FAILED: patch "[PATCH] module: fix memory leak on early load_module() failures" failed to apply to 4.9-stable tree

PATCH [email protected] 1 participant 1 message Mar 10, 2017 Stable branch

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The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From a5544880aff90baf1bd4443ac7ff65182213ffcd Mon Sep 17 00:00:00 2001

From: "Luis R. Rodriguez" <[email protected]>
Date: Fri, 10 Feb 2017 14:06:22 -0800
Subject: [PATCH] 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 <[email protected]> # v2.6.30
Fixes e180a6b7759a ("param: fix charp parameters set via sysfs")
kernel/module.c +1 -0
index 32d0d32abbf6..14da88b5d0fb 100644
@@ -3724,6 +3724,7 @@ 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);