openrisc: fix arbitrary kernel memory access via or1k_atomic syscallgrafted

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 <ali@iusegentoo.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-nvme b/Documentation/ABI/testing/sysfs-nvme
new file mode 100644
index 000000000..499d5f843
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-nvme
@@ -0,0 +1,13 @@
+What:		/sys/devices/virtual/nvme-fabrics/ctl/.../tls_configured_key
+Date:		November 2025
+KernelVersion:	6.19
+Contact:	Linux NVMe mailing list <linux-nvme@lists.infradead.org>
+Description:
+		The file is avaliable when using a secure concatanation
+		connection to a NVMe target. Reading the file will return
+		the serial of the currently negotiated key.
+
+		Writing 0 to the file will trigger a PSK reauthentication
+		(REPLACETLSPSK) with the target. After a reauthentication
+		the value returned by tls_configured_key will be the new
+		serial.