memory leak in vq_meta

memory leak in vq_meta_prefetch
Status: upstream: reported C repro on 2019/07/24 19:18
Reported-by: syzbot+a871c1e6ea00685e73d7@syzkaller.appspotmail.com
First crash: 585d, last: 585d

Cause bisection: introduced by (bisect log) :
commit 0e5f7d0b39e1f184dc25e3adb580c79e85332167
Author: Nicolas Ferre <nicolas.ferre@atmel.com>
Date: Wed Mar 16 13:19:49 2016 +0000

ARM: dts: at91: shdwc binding: add new shutdown controller documentation

Crash: memory leak in police_init_net (log)
Repro: C syz .config

Patch testing requests:
Created	Duration	User	Patch	Repo	Result
2020/10/16 23:38	16m	anant.thazhemadam@gmail.com		upstream	OK
2020/09/23 10:41	3m	anant.thazhemadam@gmail.com		upstream	error

Sample crash report:

executing program
executing program
executing program
executing program
executing program
BUG: memory leak
unreferenced object 0xffff88811b327cc0 (size 32):
  comm "vhost-7201", pid 7205, jiffies 4294952492 (age 19.700s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<000000009e106308>] kmemleak_alloc_recursive /./include/linux/kmemleak.h:43 [inline]
    [<000000009e106308>] slab_post_alloc_hook /mm/slab.h:522 [inline]
    [<000000009e106308>] slab_alloc /mm/slab.c:3319 [inline]
    [<000000009e106308>] kmem_cache_alloc_trace+0x145/0x280 /mm/slab.c:3548
    [<00000000ed2eec2d>] kmalloc /./include/linux/slab.h:552 [inline]
    [<00000000ed2eec2d>] vhost_map_prefetch /drivers/vhost/vhost.c:877 [inline]
    [<00000000ed2eec2d>] vhost_vq_map_prefetch /drivers/vhost/vhost.c:1838 [inline]
    [<00000000ed2eec2d>] vq_meta_prefetch+0x18e/0x350 /drivers/vhost/vhost.c:1849
    [<000000009d9c11b8>] handle_rx+0x9d/0xc00 /drivers/vhost/net.c:1128
    [<000000008f883d86>] handle_rx_net+0x19/0x20 /drivers/vhost/net.c:1270
    [<00000000577ffdd8>] vhost_worker+0xc6/0x120 /drivers/vhost/vhost.c:519
    [<000000001201f3db>] kthread+0x13e/0x160 /kernel/kthread.c:255
    [<00000000093cd85a>] ret_from_fork+0x1f/0x30 /arch/x86/entry/entry_64.S:352

BUG: memory leak
unreferenced object 0xffff88811b327cc0 (size 32):
  comm "vhost-7201", pid 7205, jiffies 4294952492 (age 20.600s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<000000009e106308>] kmemleak_alloc_recursive /./include/linux/kmemleak.h:43 [inline]
    [<000000009e106308>] slab_post_alloc_hook /mm/slab.h:522 [inline]
    [<000000009e106308>] slab_alloc /mm/slab.c:3319 [inline]
    [<000000009e106308>] kmem_cache_alloc_trace+0x145/0x280 /mm/slab.c:3548
    [<00000000ed2eec2d>] kmalloc /./include/linux/slab.h:552 [inline]
    [<00000000ed2eec2d>] vhost_map_prefetch /drivers/vhost/vhost.c:877 [inline]
    [<00000000ed2eec2d>] vhost_vq_map_prefetch /drivers/vhost/vhost.c:1838 [inline]
    [<00000000ed2eec2d>] vq_meta_prefetch+0x18e/0x350 /drivers/vhost/vhost.c:1849
    [<000000009d9c11b8>] handle_rx+0x9d/0xc00 /drivers/vhost/net.c:1128
    [<000000008f883d86>] handle_rx_net+0x19/0x20 /drivers/vhost/net.c:1270
    [<00000000577ffdd8>] vhost_worker+0xc6/0x120 /drivers/vhost/vhost.c:519
    [<000000001201f3db>] kthread+0x13e/0x160 /kernel/kthread.c:255
    [<00000000093cd85a>] ret_from_fork+0x1f/0x30 /arch/x86/entry/entry_64.S:352

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci-upstream-gce-leak	2019/07/23 10:18	upstream	c6dd78fc	55e0c077	.config	log	report	syz	C