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Message-Id: <1487585948-6401-10-git-send-email-elena.reshetova@intel.com>
Date: Mon, 20 Feb 2017 12:18:58 +0200
From: Elena Reshetova <elena.reshetova@...el.com>
To: linux-kernel@...r.kernel.org
Cc: cgroups@...r.kernel.org, linux-audit@...hat.com,
linux-fsdevel@...r.kernel.org, peterz@...radead.org,
gregkh@...uxfoundation.org, viro@...iv.linux.org.uk, tj@...nel.org,
mingo@...hat.com, hannes@...xchg.org, lizefan@...wei.com,
acme@...nel.org, alexander.shishkin@...ux.intel.com,
paul@...l-moore.com, eparis@...hat.com, akpm@...ux-foundation.org,
arnd@...db.de, luto@...nel.org,
Elena Reshetova <elena.reshetova@...el.com>,
Hans Liljestrand <ishkamiel@...il.com>,
Kees Cook <keescook@...omium.org>,
David Windsor <dwindsor@...il.com>
Subject: [PATCH 09/19] kernel: convert uprobe.ref from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@...el.com>
Signed-off-by: Hans Liljestrand <ishkamiel@...il.com>
Signed-off-by: Kees Cook <keescook@...omium.org>
Signed-off-by: David Windsor <dwindsor@...il.com>
---
kernel/events/uprobes.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index b62d6fe..a4b33f8 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -64,7 +64,7 @@ static struct percpu_rw_semaphore dup_mmap_sem;
struct uprobe {
struct rb_node rb_node; /* node in the rb tree */
- atomic_t ref;
+ refcount_t ref;
struct rw_semaphore register_rwsem;
struct rw_semaphore consumer_rwsem;
struct list_head pending_list;
@@ -369,13 +369,13 @@ set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long v
static struct uprobe *get_uprobe(struct uprobe *uprobe)
{
- atomic_inc(&uprobe->ref);
+ refcount_inc(&uprobe->ref);
return uprobe;
}
static void put_uprobe(struct uprobe *uprobe)
{
- if (atomic_dec_and_test(&uprobe->ref))
+ if (refcount_dec_and_test(&uprobe->ref))
kfree(uprobe);
}
@@ -457,7 +457,7 @@ static struct uprobe *__insert_uprobe(struct uprobe *uprobe)
rb_link_node(&uprobe->rb_node, parent, p);
rb_insert_color(&uprobe->rb_node, &uprobes_tree);
/* get access + creation ref */
- atomic_set(&uprobe->ref, 2);
+ refcount_set(&uprobe->ref, 2);
return u;
}
--
2.7.4
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