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

\
 
 \ /
  Last update: 2023-03-26 23:32    [W:0.053 / U:0.420 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site