From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- Documentation/netlabel/lsm_interface.rst | 53 ++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 Documentation/netlabel/lsm_interface.rst (limited to 'Documentation/netlabel/lsm_interface.rst') diff --git a/Documentation/netlabel/lsm_interface.rst b/Documentation/netlabel/lsm_interface.rst new file mode 100644 index 000000000..026fc267f --- /dev/null +++ b/Documentation/netlabel/lsm_interface.rst @@ -0,0 +1,53 @@ +======================================== +NetLabel Linux Security Module Interface +======================================== + +Paul Moore, paul.moore@hp.com + +May 17, 2006 + +Overview +======== + +NetLabel is a mechanism which can set and retrieve security attributes from +network packets. It is intended to be used by LSM developers who want to make +use of a common code base for several different packet labeling protocols. +The NetLabel security module API is defined in 'include/net/netlabel.h' but a +brief overview is given below. + +NetLabel Security Attributes +============================ + +Since NetLabel supports multiple different packet labeling protocols and LSMs +it uses the concept of security attributes to refer to the packet's security +labels. The NetLabel security attributes are defined by the +'netlbl_lsm_secattr' structure in the NetLabel header file. Internally the +NetLabel subsystem converts the security attributes to and from the correct +low-level packet label depending on the NetLabel build time and run time +configuration. It is up to the LSM developer to translate the NetLabel +security attributes into whatever security identifiers are in use for their +particular LSM. + +NetLabel LSM Protocol Operations +================================ + +These are the functions which allow the LSM developer to manipulate the labels +on outgoing packets as well as read the labels on incoming packets. Functions +exist to operate both on sockets as well as the sk_buffs directly. These high +level functions are translated into low level protocol operations based on how +the administrator has configured the NetLabel subsystem. + +NetLabel Label Mapping Cache Operations +======================================= + +Depending on the exact configuration, translation between the network packet +label and the internal LSM security identifier can be time consuming. The +NetLabel label mapping cache is a caching mechanism which can be used to +sidestep much of this overhead once a mapping has been established. Once the +LSM has received a packet, used NetLabel to decode its security attributes, +and translated the security attributes into a LSM internal identifier the LSM +can use the NetLabel caching functions to associate the LSM internal +identifier with the network packet's label. This means that in the future +when a incoming packet matches a cached value not only are the internal +NetLabel translation mechanisms bypassed but the LSM translation mechanisms are +bypassed as well which should result in a significant reduction in overhead. -- cgit v1.3.1