From: Jordan Crouse <jcrouse@codeaurora.org>
To: freedreno@lists.freedesktop.org
Cc: linux-arm-msm@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Matthew Wilcox <willy@infradead.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH] idr: Prevent unintended underflow for the idr index
Date: Tue, 17 Sep 2019 15:48:42 -0600 [thread overview]
Message-ID: <1568756922-2829-1-git-send-email-jcrouse@codeaurora.org> (raw)
It is possible for unaware callers of several idr functions to accidentally
underflow the index by specifying a id that is less than the idr base.
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
---
lib/idr.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/lib/idr.c b/lib/idr.c
index 66a3748..d9e180c 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -151,6 +151,9 @@ EXPORT_SYMBOL(idr_alloc_cyclic);
*/
void *idr_remove(struct idr *idr, unsigned long id)
{
+ if (id < idr->idr_base)
+ return NULL;
+
return radix_tree_delete_item(&idr->idr_rt, id - idr->idr_base, NULL);
}
EXPORT_SYMBOL_GPL(idr_remove);
@@ -171,6 +174,9 @@ EXPORT_SYMBOL_GPL(idr_remove);
*/
void *idr_find(const struct idr *idr, unsigned long id)
{
+ if (id < idr->idr_base)
+ return NULL;
+
return radix_tree_lookup(&idr->idr_rt, id - idr->idr_base);
}
EXPORT_SYMBOL_GPL(idr_find);
@@ -302,6 +308,9 @@ void *idr_replace(struct idr *idr, void *ptr, unsigned long id)
void __rcu **slot = NULL;
void *entry;
+ if (id < idr->idr_base)
+ return ERR_PTR(-ENOENT);
+
id -= idr->idr_base;
entry = __radix_tree_lookup(&idr->idr_rt, id, &node, &slot);
--
2.7.4
next reply other threads:[~2019-09-17 21:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-17 21:48 Jordan Crouse [this message]
2019-09-18 11:50 ` [PATCH] idr: Prevent unintended underflow for the idr index Matthew Wilcox
2019-09-18 15:32 ` Jordan Crouse
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