From: Oleg Nesterov <oleg@redhat.com>
Date: Mon, 31 Dec 2012 17:12:48 +0000 (+0100)
Subject: uprobes: Fix utask->xol_vaddr leak in pre_ssout()
X-Git-Tag: firefly_0821_release~3680^2~1126^2~2^2~15
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=aba51024e7159c93914557caaa2b8cda26331091;p=firefly-linux-kernel-4.4.55.git

uprobes: Fix utask->xol_vaddr leak in pre_ssout()

pre_ssout() should do xol_free_insn_slot() if arch_uprobe_pre_xol()
fails, otherwise nobody will free the allocated slot.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 8d9c5bcb110e..0527379dac5b 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1306,6 +1306,7 @@ pre_ssout(struct uprobe *uprobe, struct pt_regs *regs, unsigned long bp_vaddr)
 {
 	struct uprobe_task *utask;
 	unsigned long xol_vaddr;
+	int err;
 
 	utask = current->utask;
 
@@ -1316,7 +1317,13 @@ pre_ssout(struct uprobe *uprobe, struct pt_regs *regs, unsigned long bp_vaddr)
 	utask->xol_vaddr = xol_vaddr;
 	utask->vaddr = bp_vaddr;
 
-	return arch_uprobe_pre_xol(&uprobe->arch, regs);
+	err = arch_uprobe_pre_xol(&uprobe->arch, regs);
+	if (unlikely(err)) {
+		xol_free_insn_slot(current);
+		return err;
+	}
+
+	return 0;
 }
 
 /*