From: Uros Bizjak Date: Fri, 1 Dec 2023 08:57:27 +0000 (+0100) Subject: x86/callthunks: Correct calculation of dest address in is_callthunk() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=fc50065325f8b88d6986f089ae103b5db858ab96;p=linux.git x86/callthunks: Correct calculation of dest address in is_callthunk() GCC didn't warn on the invalid use of relocation destination pointer, so the calculated destination value was applied to the uninitialized pointer location in error. Fixes: 17bce3b2ae2d ("x86/callthunks: Handle %rip-relative relocations in call thunk template") Reported-by: Nathan Chancellor Signed-off-by: Uros Bizjak Signed-off-by: Ingo Molnar Closes: https://lore.kernel.org/lkml/20231201035457.GA321497@dev-arch.thelio-3990X/ Link: https://lore.kernel.org/r/20231201085727.3647051-1-ubizjak@gmail.com --- diff --git a/arch/x86/kernel/callthunks.c b/arch/x86/kernel/callthunks.c index f56fa303d6431..2324c7f9a8413 100644 --- a/arch/x86/kernel/callthunks.c +++ b/arch/x86/kernel/callthunks.c @@ -312,7 +312,7 @@ static bool is_callthunk(void *addr) if (!thunks_initialized || skip_addr((void *)dest)) return false; - *pad = dest - tmpl_size; + pad = (void *)(dest - tmpl_size); memcpy(insn_buff, skl_call_thunk_template, tmpl_size); apply_relocation(insn_buff, tmpl_size, pad,