Messages in this thread | | | Subject | Re: [PATCH] kernfs: fix potential null-ptr-deref in kernfs_path_from_node_locked() | From | "Leizhen (ThunderTown)" <> | Date | Mon, 28 Nov 2022 09:15:23 +0800 |
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On 2022/11/26 18:25, Greg Kroah-Hartman wrote: > On Sat, Nov 26, 2022 at 05:49:50PM +0800, Leizhen (ThunderTown) wrote: >> >> >> On 2022/11/24 10:52, Leizhen (ThunderTown) wrote: >>> >>> >>> On 2022/11/24 10:28, Leizhen (ThunderTown) wrote: >>>> >>>> >>>> On 2022/11/24 10:24, Leizhen (ThunderTown) wrote: >>>>> >>>>> >>>>> On 2022/11/24 0:55, Tejun Heo wrote: >>>>>> On Wed, Nov 23, 2022 at 10:04:19AM +0800, Zhen Lei wrote: >>>>>>> Ensure that the 'buf' is not empty before strlcpy() uses it. >>>>>>> >>>>>>> Commit bbe70e4e4211 ("fs: kernfs: Fix possible null-pointer dereferences >>>>>>> in kernfs_path_from_node_locked()") first noticed this, but it didn't >>>>>>> fix it completely. >>>>>>> >>>>>>> Fixes: 9f6df573a404 ("kernfs: Add API to generate relative kernfs path") >>>>>>> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> >>>>>> >>>>>> I think the right thing to do is removing that if. It makes no sense to call >>>>>> that function with NULL buf and the fact that nobody reported crashes on >>>>>> NULL buf indicates that we in fact never do. >> >> kernfs_path_from_node >> -->kernfs_path_from_node_locked >> >> EXPORT_SYMBOL_GPL(kernfs_path_from_node) >> >> I've rethought it. The export APIs need to do null pointer check, right? > > No, callers should get this right. Are there any in-tree ones that do > not?
Thanks. I got it.
> > thanks, > > greg k-h > . >
-- Regards, Zhen Lei
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