1f1feff02e
commit 0974d03eb479384466d828d65637814bee6b26d7 upstream. Smatch warns: arch/powerpc/kernel/rtas.c:1932 __do_sys_rtas() warn: potential spectre issue 'args.args' [r] (local cap) The 'nargs' and 'nret' locals come directly from a user-supplied buffer and are used as indexes into a small stack-based array and as inputs to copy_to_user() after they are subject to bounds checks. Use array_index_nospec() after the bounds checks to clamp these values for speculative execution. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reported-by: Breno Leitao <leitao@debian.org> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240530-sys_rtas-nargs-nret-v1-1-129acddd4d89@linux.ibm.com [Minor context change fixed] Signed-off-by: Cliff Liu <donghua.liu@windriver.com> Signed-off-by: He Zhe <Zhe.He@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>