From 90718e32e1dcc2479acfa208ccfc6442850b594c Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@redhat.com>
Date: Fri, 18 May 2018 18:27:39 +0200
Subject: [PATCH] uprobes/x86: Remove incorrect WARN_ON() in uprobe_init_insn()
Git-commit: 90718e32e1dcc2479acfa208ccfc6442850b594c
Patch-mainline: v4.18-rc2
References: bsc#1051510
insn_get_length() has the side-effect of processing the entire instruction
but only if it was decoded successfully, otherwise insn_complete() can fail
and in this case we need to just return an error without warning.
Reported-by: syzbot+30d675e3ca03c1c351e7@syzkaller.appspotmail.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: syzkaller-bugs@googlegroups.com
Link: https://lkml.kernel.org/lkml/20180518162739.GA5559@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
arch/x86/kernel/uprobes.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 58d8d800875d..deb576b23b7c 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -293,7 +293,7 @@ static int uprobe_init_insn(struct arch_uprobe *auprobe, struct insn *insn, bool
insn_init(insn, auprobe->insn, sizeof(auprobe->insn), x86_64);
/* has the side-effect of processing the entire instruction */
insn_get_length(insn);
- if (WARN_ON_ONCE(!insn_complete(insn)))
+ if (!insn_complete(insn))
return -ENOEXEC;
if (is_prefix_bad(insn))
--
2.18.0