Messages in this thread | | | Date | Mon, 9 Jan 2023 11:33:17 +0100 | From | Greg KH <> | Subject | Re: [PATCH v2] kobject: Fix slab-out-of-bounds in fill_kobj_path() |
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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
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