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 --- net/dns_resolver/Kconfig | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 net/dns_resolver/Kconfig (limited to 'net/dns_resolver/Kconfig') diff --git a/net/dns_resolver/Kconfig b/net/dns_resolver/Kconfig new file mode 100644 index 000000000..7c2dba273 --- /dev/null +++ b/net/dns_resolver/Kconfig @@ -0,0 +1,28 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Configuration for DNS Resolver +# +config DNS_RESOLVER + tristate "DNS Resolver support" + depends on KEYS + help + Saying Y here will include support for the DNS Resolver key type + which can be used to make upcalls to perform DNS lookups in + userspace. + + DNS Resolver is used to query DNS server for information. Examples + being resolving a UNC hostname element to an IP address for CIFS or + performing a DNS query for AFSDB records so that AFS can locate a + cell's volume location database servers. + + DNS Resolver is used by the CIFS and AFS modules, and would support + SMB2 later. DNS Resolver is supported by the userspace upcall + helper "/sbin/dns.resolver" via /etc/request-key.conf. + + See for further + information. + + To compile this as a module, choose M here: the module will be called + dns_resolver. + + If unsure, say N. -- cgit v1.3.1