[PATCH 5/7] uprobes: Fix utask->xol_vaddr leak in pre_ssout()

From: Oleg Nesterov
Date: Mon Dec 31 2012 - 12:52:32 EST


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@xxxxxxxxxx>
---
kernel/events/uprobes.c | 9 ++++++++-
1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 2ed6239..bd94d2c 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;
}

/*
--
1.5.5.1

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