From: Sasha Levin <sasha.levin@oracle.com>
To: linux-kernel@vger.kernel.org
Cc: Sasha Levin <sasha.levin@oracle.com>,
Hugh Dickins <hughd@google.com>,
linux-mm@kvack.org
Subject: [PATCH] mm: shmem: avoid overflowing in shmem_fallocate
Date: Wed, 3 Dec 2014 19:24:07 -0500 [thread overview]
Message-ID: <1417652657-1801-1-git-send-email-sasha.levin@oracle.com> (raw)
"offset + len" has the potential of overflowing. Validate this user input
first to avoid undefined behaviour.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---
mm/shmem.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mm/shmem.c b/mm/shmem.c
index 185836b..5a0e344 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2098,6 +2098,9 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
}
/* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */
+ error = -EOVERFLOW;
+ if ((u64)len + offset < (u64)len)
+ goto out;
error = inode_newsize_ok(inode, offset + len);
if (error)
goto out;
--
1.7.10.4
--
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next reply other threads:[~2014-12-04 0:24 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-04 0:24 Sasha Levin [this message]
2014-12-04 1:51 ` Naoya Horiguchi
2014-12-04 2:33 ` Sasha Levin
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