Messages in this thread Patch in this message | | | From | Ilya Matveychikov <> | Subject | [PATCH] ksys_mount: check for permissions before resource allocation | Date | Tue, 5 Jun 2018 06:00:47 +0400 |
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Early check for mount permissions prevents possible allocation of 3 pages from kmalloc() pool by unpriveledged user which can be used for spraying the kernel heap.
Signed-off-by: Ilya V. Matveychikov <matvejchikov@gmail.com> --- fs/namespace.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/fs/namespace.c b/fs/namespace.c index 5f75969adff1..1ef8feb2de2a 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -3046,6 +3046,9 @@ int ksys_mount(char __user *dev_name, char __user *dir_name, char __user *type, char *kernel_dev; void *options;
+ if (!may_mount()) + return -EPERM; + kernel_type = copy_mount_string(type); ret = PTR_ERR(kernel_type); if (IS_ERR(kernel_type)) -- 2.17.0
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