lkml.org 
[lkml]   [2023]   [Jan]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v2] kobject: Fix slab-out-of-bounds in fill_kobj_path()
From

在 2023/1/9 18:33, Greg KH 写道:
> On Mon, Jan 09, 2023 at 05:37:23PM +0800, Wang Hai wrote:
>> 在 2022/12/20 9:21, Wang Hai 写道:
>>> In kobject_get_path(), if kobj->name is changed between calls
>>> get_kobj_path_length() and fill_kobj_path() and the length becomes
>>> longer, then fill_kobj_path() will have an out-of-bounds bug.
>>>
>>> The actual current problem occurs when the ixgbe probe.
>>>
>>> In ixgbe_mii_bus_init(), if the length of netdev->dev.kobj.name
>>> length becomes longer, out-of-bounds will occur.
>>>
>>> cpu0 cpu1
>>> ixgbe_probe
>>> register_netdev(netdev)
>>> netdev_register_kobject
>>> device_add
>>> kobject_uevent // Sending ADD events
>>> systemd-udevd // rename netdev
>>> dev_change_name
>>> device_rename
>>> kobject_rename
>>> ixgbe_mii_bus_init |
>>> mdiobus_register |
>>> __mdiobus_register |
>>> device_register |
>>> device_add |
>>> kobject_uevent |
>>> kobject_get_path |
>>> len = get_kobj_path_length // old name |
>>> path = kzalloc(len, gfp_mask); |
>>> kobj->name = name;
>>> /* name length becomes
>>> * longer
>>> */
>>> fill_kobj_path /* kobj path length is
>>> * longer than path,
>>> * resulting in out of
>>> * bounds when filling path
>>> */
>>>
>>> This is the kasan report:
>>>
>>> ==================================================================
>>> BUG: KASAN: slab-out-of-bounds in fill_kobj_path+0x50/0xc0
>>> Write of size 7 at addr ff1100090573d1fd by task kworker/28:1/673
>>>
>>> Workqueue: events work_for_cpu_fn
>>> Call Trace:
>>> <TASK>
>>> dump_stack_lvl+0x34/0x48
>>> print_address_description.constprop.0+0x86/0x1e7
>>> print_report+0x36/0x4f
>>> kasan_report+0xad/0x130
>>> kasan_check_range+0x35/0x1c0
>>> memcpy+0x39/0x60
>>> fill_kobj_path+0x50/0xc0
>>> kobject_get_path+0x5a/0xc0
>>> kobject_uevent_env+0x140/0x460
>>> device_add+0x5c7/0x910
>>> __mdiobus_register+0x14e/0x490
>>> ixgbe_probe.cold+0x441/0x574 [ixgbe]
>>> local_pci_probe+0x78/0xc0
>>> work_for_cpu_fn+0x26/0x40
>>> process_one_work+0x3b6/0x6a0
>>> worker_thread+0x368/0x520
>>> kthread+0x165/0x1a0
>>> ret_from_fork+0x1f/0x30
>>>
>>> This reproducer triggers that bug:
>>>
>>> while:
>>> do
>>> rmmod ixgbe
>>> sleep 0.5
>>> modprobe ixgbe
>>> sleep 0.5
>>>
>>> When calling fill_kobj_path() to fill path, if the name length of
>>> kobj becomes longer, return failure and retry. This fixes the problem.
>>>
>>> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
>>> Signed-off-by: Wang Hai <wanghai38@huawei.com>
>>> ---
>> Hi, greg k-h.
>> Sorry to bother you. Can this patch be merged into the mainline?
> It's in my "to review" queue that I am working on. As this is not
> anything that a normal user can trigger, it's not that high of a
> priority, right?
>
> thanks,
>
> greg k-h
> .
Thanks, I thought you had forgotten about it. I hope I'm not disturbing you.

--
Wang Hai

\
 
 \ /
  Last update: 2023-03-26 23:32    [W:0.037 / U:0.172 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site