Re: [PATCH] s390/kprobes: Prevent kprobes on instructions with exception table entry

[Heiko Carstens]

On Thu, Sep 24, 2026 at 01:57:24PM +0200, Heiko Carstens wrote:
> The mvcos exception handler ex_handler_ua_mvcos() decodes the faulting
> instruction, assuming it is an mvcos instruction. In case the instruction
> is kprobed the decoded instruction is a breakpoint instruction instead,
> which leads to incorrect instruction decoding and potential register
> corruption.
> 
> Fix this by simply preventing to set a kprobe on such instructions,
> similar like arm64 is doing it.
> 
> Fixes: c488f5187a24 ("s390/uaccess: Shorten raw_copy_from_user() / raw_copy_to_user() inline assemblies")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
> ---
>  arch/s390/kernel/kprobes.c | 3 +++
>  1 file changed, 3 insertions(+)

This patch has been integrated as first patch into
https://lore.kernel.org/all/20261001103247.1989111-1-hca@xxxxxxxxxxxxx/