From: Josh Poimboeuf jpoimboe@redhat.com
stable inclusion from stable-v5.10.133 commit 53e89bc78e4351924a1a1474683d47a00c2633f2 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 ecf11ba4d066fe527586c6edd6ca68457ca55cf4 upstream.
There's an inconsistency in how sibling calls are detected in non-function asm code, depending on the scope of the object. If the target code is external to the object, objtool considers it a sibling call. If the target code is internal but not a function, objtool *doesn't* consider it a sibling call.
This can cause some inconsistencies between per-object and vmlinux.o validation.
Instead, assume only ELF functions can do sibling calls. This generally matches existing reality, and makes sibling call validation consistent between vmlinux.o and per-object.
Signed-off-by: Josh Poimboeuf jpoimboe@redhat.com Link: https://lore.kernel.org/r/0e9ab6f3628cc7bf3bde7aa6762d54d7df19ad78.161126346... 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/check.c | 36 ++++++++++++++++++++++-------------- 1 file changed, 22 insertions(+), 14 deletions(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 4f8a760bffca..29e4fca80258 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -109,15 +109,20 @@ static struct instruction *prev_insn_same_sym(struct objtool_file *file,
static bool is_sibling_call(struct instruction *insn) { + /* + * Assume only ELF functions can make sibling calls. This ensures + * sibling call detection consistency between vmlinux.o and individual + * objects. + */ + if (!insn->func) + return false; + /* An indirect jump is either a sibling call or a jump to a table. */ if (insn->type == INSN_JUMP_DYNAMIC) return list_empty(&insn->alts);
- if (!is_static_jump(insn)) - return false; - /* add_jump_destinations() sets insn->call_dest for sibling calls. */ - return !!insn->call_dest; + return (is_static_jump(insn) && insn->call_dest); }
/* @@ -788,7 +793,7 @@ static int add_jump_destinations(struct objtool_file *file) continue;
reloc = find_reloc_by_dest_range(file->elf, insn->sec, - insn->offset, insn->len); + insn->offset, insn->len); if (!reloc) { dest_sec = insn->sec; dest_off = arch_jump_destination(insn); @@ -808,18 +813,21 @@ static int add_jump_destinations(struct objtool_file *file)
insn->retpoline_safe = true; continue; - } else if (reloc->sym->sec->idx) { - dest_sec = reloc->sym->sec; - dest_off = reloc->sym->sym.st_value + - arch_dest_reloc_offset(reloc->addend); - } else { - /* external sibling call */ + } else if (insn->func) { + /* internal or external sibling call (with reloc) */ insn->call_dest = reloc->sym; if (insn->call_dest->static_call_tramp) { list_add_tail(&insn->static_call_node, &file->static_call_list); } continue; + } else if (reloc->sym->sec->idx) { + dest_sec = reloc->sym->sec; + dest_off = reloc->sym->sym.st_value + + arch_dest_reloc_offset(reloc->addend); + } else { + /* non-func asm code jumping to another file */ + continue; }
insn->jump_dest = find_insn(file, dest_sec, dest_off); @@ -868,7 +876,7 @@ static int add_jump_destinations(struct objtool_file *file) } else if (insn->jump_dest->func->pfunc != insn->func->pfunc && insn->jump_dest->offset == insn->jump_dest->func->offset) {
- /* internal sibling call */ + /* internal sibling call (without reloc) */ insn->call_dest = insn->jump_dest->func; if (insn->call_dest->static_call_tramp) { list_add_tail(&insn->static_call_node, @@ -2570,7 +2578,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
case INSN_JUMP_CONDITIONAL: case INSN_JUMP_UNCONDITIONAL: - if (func && is_sibling_call(insn)) { + if (is_sibling_call(insn)) { ret = validate_sibling_call(insn, &state); if (ret) return ret; @@ -2592,7 +2600,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
case INSN_JUMP_DYNAMIC: case INSN_JUMP_DYNAMIC_CONDITIONAL: - if (func && is_sibling_call(insn)) { + if (is_sibling_call(insn)) { ret = validate_sibling_call(insn, &state); if (ret) return ret;