From: Alan Stern <stern@rowland.harvard.edu>
To: syzbot <syzbot+44e64397bd81d5e84cba@syzkaller.appspotmail.com>,
linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: Re: memory leak in hub_event
Date: Mon, 23 Nov 2020 14:32:30 -0500 [thread overview]
Message-ID: <20201123193230.GA718753@rowland.harvard.edu> (raw)
In-Reply-To: <00000000000031907005b4ca944b@google.com>
[CC list trimmed. I assume most people don't care about the boring
debugging details.]
On Mon, Nov 23, 2020 at 10:44:06AM -0800, syzbot wrote:
> Hello,
>
> syzbot has tested the proposed patch but the reproducer is still triggering an issue:
> memory leak in rxrpc_lookup_local
>
> write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory
> write to /proc/sys/kernel/softlockup_all_cpu_backtrace failed: No such file or directory
> BUG: memory leak
> unreferenced object 0xffff888117824d00 (size 256):
> comm "syz-executor.6", pid 8896, jiffies 4294943994 (age 432.900s)
> 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 0a 00 00 00 00 00 ad 17 81 88 ff ff ................
> backtrace:
> [<0000000069b066ee>] kmalloc include/linux/slab.h:552 [inline]
> [<0000000069b066ee>] kzalloc include/linux/slab.h:664 [inline]
> [<0000000069b066ee>] rxrpc_alloc_local net/rxrpc/local_object.c:79 [inline]
> [<0000000069b066ee>] rxrpc_lookup_local+0x1c1/0x760 net/rxrpc/local_object.c:244
> [<0000000085db7132>] rxrpc_bind+0x174/0x240 net/rxrpc/af_rxrpc.c:149
> [<00000000a2a77c59>] afs_open_socket+0xdb/0x200 fs/afs/rxrpc.c:64
> [<0000000086f4a248>] afs_net_init+0x2b4/0x340 fs/afs/main.c:126
I don't know what all this rxrpc or afs stuff is about, but it doesn't
seem to have anything to do with gspca. So it's a good bet that the
patch bailed out before the unreleased reference was acquired.
Let's try another spot. Binary search should find the right place
quickly enough.
Alan Stern
#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 4d02da97
Index: usb-devel/drivers/media/usb/gspca/gspca.c
===================================================================
--- usb-devel.orig/drivers/media/usb/gspca/gspca.c
+++ usb-devel/drivers/media/usb/gspca/gspca.c
@@ -1489,6 +1489,8 @@ int gspca_dev_probe2(struct usb_interfac
}
gspca_dev->v4l2_dev.release = gspca_release;
+// ret = -EIO;
+// goto out;
ret = v4l2_device_register(&intf->dev, &gspca_dev->v4l2_dev);
if (ret)
goto out;
@@ -1530,6 +1532,7 @@ int gspca_dev_probe2(struct usb_interfac
if (ret < 0)
goto out;
ret = sd_desc->init(gspca_dev);
+ ret = -EIO;
if (ret < 0)
goto out;
if (sd_desc->init_controls)
next prev parent reply other threads:[~2020-11-23 19:32 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-20 15:15 memory leak in hub_event syzbot
2020-11-20 16:56 ` Alan Stern
2020-11-20 16:56 ` syzbot
2020-11-20 17:00 ` Alan Stern
2020-11-23 18:29 ` Andrey Konovalov
2020-11-23 18:44 ` syzbot
2020-11-23 19:32 ` Alan Stern [this message]
2020-11-23 19:42 ` syzbot
2020-11-23 19:53 ` Alan Stern
2020-11-23 20:01 ` syzbot
2020-11-23 20:38 ` Alan Stern
2020-11-23 20:48 ` syzbot
2020-11-23 21:53 ` Alan Stern
2020-11-23 22:09 ` syzbot
2020-11-23 22:24 ` Alan Stern
2020-11-24 11:38 ` Hans Verkuil
2020-11-24 16:00 ` [PATCH] media: gspca: Fix memory leak in probe Alan Stern
2020-12-02 8:58 ` Hans Verkuil
2020-12-02 17:20 ` [PATCH v2] " Alan Stern
2020-12-02 16:22 ` memory leak in hub_event Alan Stern
2020-12-02 16:37 ` syzbot
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