Messages in this thread | | | Date | Mon, 9 Jan 2023 19:15:05 +0800 | Subject | Re: [PATCH v2] kobject: Fix slab-out-of-bounds in fill_kobj_path() | From | Wang Hai <> |
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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
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