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/rxrpc/call_state.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 net/rxrpc/call_state.c (limited to 'net/rxrpc/call_state.c') diff --git a/net/rxrpc/call_state.c b/net/rxrpc/call_state.c new file mode 100644 index 000000000..6afb54373 --- /dev/null +++ b/net/rxrpc/call_state.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Call state changing functions. + * + * Copyright (C) 2022 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include "ar-internal.h" + +/* + * Transition a call to the complete state. + */ +bool rxrpc_set_call_completion(struct rxrpc_call *call, + enum rxrpc_call_completion compl, + u32 abort_code, + int error) +{ + if (__rxrpc_call_state(call) == RXRPC_CALL_COMPLETE) + return false; + + call->abort_code = abort_code; + call->error = error; + call->completion = compl; + /* Allow reader of completion state to operate locklessly */ + rxrpc_set_call_state(call, RXRPC_CALL_COMPLETE); + trace_rxrpc_call_complete(call); + wake_up(&call->waitq); + rxrpc_notify_socket(call); + return true; +} + +/* + * Record that a call successfully completed. + */ +bool rxrpc_call_completed(struct rxrpc_call *call) +{ + return rxrpc_set_call_completion(call, RXRPC_CALL_SUCCEEDED, 0, 0); +} + +/* + * Record that a call is locally aborted. + */ +bool rxrpc_abort_call(struct rxrpc_call *call, rxrpc_seq_t seq, + u32 abort_code, int error, enum rxrpc_abort_reason why) +{ + trace_rxrpc_abort(call->debug_id, why, call->cid, call->call_id, seq, + abort_code, error); + if (!rxrpc_set_call_completion(call, RXRPC_CALL_LOCALLY_ABORTED, + abort_code, error)) + return false; + if (test_bit(RXRPC_CALL_EXPOSED, &call->flags)) + rxrpc_send_abort_packet(call); + return true; +} + +/* + * Record that a call errored out before even getting off the ground, thereby + * setting the state to allow it to be destroyed. + */ +void rxrpc_prefail_call(struct rxrpc_call *call, enum rxrpc_call_completion compl, + int error) +{ + call->abort_code = RX_CALL_DEAD; + call->error = error; + call->completion = compl; + call->_state = RXRPC_CALL_COMPLETE; + trace_rxrpc_call_complete(call); + WARN_ON_ONCE(__test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)); +} -- cgit v1.3.1