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/networking/ipv6.rst | 78 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 Documentation/networking/ipv6.rst (limited to 'Documentation/networking/ipv6.rst') diff --git a/Documentation/networking/ipv6.rst b/Documentation/networking/ipv6.rst new file mode 100644 index 000000000..ba09c2f2d --- /dev/null +++ b/Documentation/networking/ipv6.rst @@ -0,0 +1,78 @@ +.. SPDX-License-Identifier: GPL-2.0 + +==== +IPv6 +==== + + +Options for the ipv6 module are supplied as parameters at load time. + +Module options may be given as command line arguments to the insmod +or modprobe command, but are usually specified in either +``/etc/modules.d/*.conf`` configuration files, or in a distro-specific +configuration file. + +The available ipv6 module parameters are listed below. If a parameter +is not specified the default value is used. + +The parameters are as follows: + +disable + + Specifies whether to load the IPv6 module, but disable all + its functionality. This might be used when another module + has a dependency on the IPv6 module being loaded, but no + IPv6 addresses or operations are desired. + + The possible values and their effects are: + + 0 + IPv6 is enabled. + + This is the default value. + + 1 + IPv6 is disabled. + + No IPv6 addresses will be added to interfaces, and + it will not be possible to open an IPv6 socket. + + A reboot is required to enable IPv6. + +autoconf + + Specifies whether to enable IPv6 address autoconfiguration + on all interfaces. This might be used when one does not wish + for addresses to be automatically generated from prefixes + received in Router Advertisements. + + The possible values and their effects are: + + 0 + IPv6 address autoconfiguration is disabled on all interfaces. + + Only the IPv6 loopback address (::1) and link-local addresses + will be added to interfaces. + + 1 + IPv6 address autoconfiguration is enabled on all interfaces. + + This is the default value. + +disable_ipv6 + + Specifies whether to disable IPv6 on all interfaces. + This might be used when no IPv6 addresses are desired. + + The possible values and their effects are: + + 0 + IPv6 is enabled on all interfaces. + + This is the default value. + + 1 + IPv6 is disabled on all interfaces. + + No IPv6 addresses will be added to interfaces. + -- cgit v1.3.1