"offset + len" has the potential of overflowing. Validate this user input
first to avoid undefined behaviour.
Signed-off-by: Sasha Levin <sasha.le...@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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