Re: [PATCH] kho: fix error handling in kho_add_subtree()

[Breno Leitao <leitao@debian.org>]

On Thu, Apr 09, 2026 at 03:08:02PM -0700, Andrew Morton wrote:
> On Tue, 07 Apr 2026 10:01:47 -0700 Breno Leitao <leitao@debian.org> wrote:
>
> > Fix two error handling issues in kho_add_subtree(), where it doesn't
> > handle the error path correctly.
> >
> > 1. If fdt_setprop() fails after the subnode has been created, the
> >    subnode is not removed. This leaves an incomplete node in the FDT
> >    (missing "preserved-data" or "blob-size" properties).
> >
> > 2. The fdt_setprop() return value (an FDT error code) is stored
> >    directly in err and returned to the caller, which expects -errno.
> >
> > Fix both by storing fdt_setprop() results in fdt_err, jumping to a new
> > out_del_node label that removes the subnode on failure, and only setting
> > err = 0 on the success path, otherwise returning -ENOMEM (instead of
> > FDT_ERR_ errors that would come from fdt_setprop).
> >
> > Fixes: 3dc92c311498 ("kexec: add Kexec HandOver (KHO) generation helpers")
>
> v6.16.
>
> > Suggested-by: Pratyush Yadav <pratyush@kernel.org>
> > Signed-off-by: Breno Leitao <leitao@debian.org>
> > ---
> >  kernel/liveupdate/kexec_handover.c | 21 +++++++++++++--------
> >  1 file changed, 13 insertions(+), 8 deletions(-)
>
> Do -stable kernels want this?
>
> Changelog is missing a description of userspace-visible effects, So I
> (and others) can't tell!

Agreed. I'll improve the changelog to describe the user-visible impact
and CC stable in v2.