Merge tag 'core_urgent_for_v5.9_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

torvalds · torvalds · commit e2bff391caba · 2020-09-20T15:37:15.000-07:00
Pull syscall tracing fix from Borislav Petkov:
 "Fix the seccomp syscall rewriting so that trace and audit see the
  rewritten syscall number, from Kees Cook"

* tag 'core_urgent_for_v5.9_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  core/entry: Report syscall correctly for trace and audit
diff --git a/kernel/entry/common.c b/kernel/entry/common.c
@@ -60,13 +60,15 @@ static long syscall_trace_enter(struct pt_regs *regs, long syscall,
 			return ret;
 	}
 
+	/* Either of the above might have changed the syscall number */
+	syscall = syscall_get_nr(current, regs);
+
 	if (unlikely(ti_work & _TIF_SYSCALL_TRACEPOINT))
 		trace_sys_enter(regs, syscall);
 
 	syscall_enter_audit(regs, syscall);
 
-	/* The above might have changed the syscall number */
-	return ret ? : syscall_get_nr(current, regs);
+	return ret ? : syscall;
 }
 
 static __always_inline long

Original file line number	Diff line number	Diff line change
`@@ -60,13 +60,15 @@ static long syscall_trace_enter(struct pt_regs *regs, long syscall,`
`60`	`60`	`return ret;`
`61`	`61`	`}`
`62`	`62`
	`63`	`+ /* Either of the above might have changed the syscall number */`
	`64`	`+ syscall = syscall_get_nr(current, regs);`
	`65`	`+`
`63`	`66`	`if (unlikely(ti_work & _TIF_SYSCALL_TRACEPOINT))`
`64`	`67`	`trace_sys_enter(regs, syscall);`
`65`	`68`
`66`	`69`	`syscall_enter_audit(regs, syscall);`
`67`	`70`
`68`		`- /* The above might have changed the syscall number */`
`69`		`- return ret ? : syscall_get_nr(current, regs);`
	`71`	`+ return ret ? : syscall;`
`70`	`72`	`}`
`71`	`73`
`72`	`74`	`static __always_inline long`