Re: [PATCH] liveupdate: check for duplicate session before growing block set

[Pratyush Yadav]

On Tue, Nov 03 2026, Christian Aurich Zanettini Martins wrote:

> luo_session_insert() grows the outgoing block set before checking for a
> duplicate session name. On -EEXIST the new block stays in the set.
>
> If the session count is an exact multiple of the per-block capacity (51
> with 4K pages), that block stays empty. It is serialized with count 0,
> which kho_block_set_restore() rejects in the next kernel:
>
>   luo: Block contains invalid entry count: 0
>   Kernel panic - not syncing: The incoming tree failed to initialize properly [-EINVAL], disabling live update
>
> Check for the duplicate before growing the block set, as
> luo_preserve_file() does with the token.
>
> Fixes: 2a441a14c2c0 ("liveupdate: Remove limit on the number of sessions")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Christian Aurich Zanettini Martins <christian.aurichzm@xxxxxxxxx>

Reviewed-by: Pratyush Yadav (Google) <pratyush@xxxxxxxxxx>

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-- 
Regards,
Pratyush Yadav