From: Peter Zijlstra peterz@infradead.org
stable inclusion from stable-v5.10.133 commit e32542e9ed362bf8ea48941d965495e1593b5cef category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5PTAS CVE: CVE-2022-29900,CVE-2022-23816,CVE-2022-29901
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 2d49b721dc18c113d5221f4cf5a6104eb66cb7f2 upstream.
It turns out that the compilers generate conditional branches to the retpoline thunks like:
5d5: 0f 85 00 00 00 00 jne 5db <cpuidle_reflect+0x22> 5d7: R_X86_64_PLT32 __x86_indirect_thunk_r11-0x4
while the rewrite can only handle JMP/CALL to the thunks. The result is the alternative wrecking the code. Make sure to skip writing the alternatives for conditional branches.
Fixes: 9bc0bb50727c ("objtool/x86: Rewrite retpoline thunk calls") Reported-by: Lukasz Majczak lma@semihalf.com Reported-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Tested-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Ben Hutchings ben@decadent.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Lin Yujun linyujun809@huawei.com Reviewed-by: Zhang Jianhua chris.zjh@huawei.com --- tools/objtool/arch/x86/decode.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 4154921291d0..09035e28f472 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -674,6 +674,10 @@ int arch_rewrite_retpolines(struct objtool_file *file)
list_for_each_entry(insn, &file->retpoline_call_list, call_node) {
+ if (insn->type != INSN_JUMP_DYNAMIC && + insn->type != INSN_CALL_DYNAMIC) + continue; + if (!strcmp(insn->sec->name, ".text.__x86.indirect_thunk")) continue;