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authorJiang Liu <liuj97@gmail.com>2012-02-03 15:37:16 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-02-13 11:06:06 -0800
commit603b63484725a6e88e4ae5da58716efd88154b1e (patch)
tree60749779f5d0425c12455805280fe4dbff1ab955 /kernel
parent55d9f089521b1355cdd6914d1186ae02ddc0f74f (diff)
kprobes: fix a memory leak in function pre_handler_kretprobe()
commit 55ca6140e9bb307efc97a9301a4f501de02a6fd6 upstream. In function pre_handler_kretprobe(), the allocated kretprobe_instance object will get leaked if the entry_handler callback returns non-zero. This may cause all the preallocated kretprobe_instance objects exhausted. This issue can be reproduced by changing samples/kprobes/kretprobe_example.c to probe "mutex_unlock". And the fix is straightforward: just put the allocated kretprobe_instance object back onto the free_instances list. [akpm@linux-foundation.org: use raw_spin_lock/unlock] Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Acked-by: Jim Keniston <jkenisto@us.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/kprobes.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index e0f0bdd92ca2..749340c1e6fc 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1660,8 +1660,12 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p,
ri->rp = rp;
ri->task = current;
- if (rp->entry_handler && rp->entry_handler(ri, regs))
+ if (rp->entry_handler && rp->entry_handler(ri, regs)) {
+ raw_spin_lock_irqsave(&rp->lock, flags);
+ hlist_add_head(&ri->hlist, &rp->free_instances);
+ raw_spin_unlock_irqrestore(&rp->lock, flags);
return 0;
+ }
arch_prepare_kretprobe(ri, regs);