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 --- fs/netfs/stats.c | 103 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100644 fs/netfs/stats.c (limited to 'fs/netfs/stats.c') diff --git a/fs/netfs/stats.c b/fs/netfs/stats.c new file mode 100644 index 000000000..ab6b916ad --- /dev/null +++ b/fs/netfs/stats.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Netfs support statistics + * + * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include +#include "internal.h" + +atomic_t netfs_n_rh_dio_read; +atomic_t netfs_n_rh_readahead; +atomic_t netfs_n_rh_read_folio; +atomic_t netfs_n_rh_read_single; +atomic_t netfs_n_rh_rreq; +atomic_t netfs_n_rh_sreq; +atomic_t netfs_n_rh_download; +atomic_t netfs_n_rh_download_done; +atomic_t netfs_n_rh_download_failed; +atomic_t netfs_n_rh_download_instead; +atomic_t netfs_n_rh_read; +atomic_t netfs_n_rh_read_done; +atomic_t netfs_n_rh_read_failed; +atomic_t netfs_n_rh_zero; +atomic_t netfs_n_rh_short_read; +atomic_t netfs_n_rh_write; +atomic_t netfs_n_rh_write_begin; +atomic_t netfs_n_rh_write_done; +atomic_t netfs_n_rh_write_failed; +atomic_t netfs_n_rh_write_zskip; +atomic_t netfs_n_rh_retry_read_req; +atomic_t netfs_n_rh_retry_read_subreq; +atomic_t netfs_n_wh_buffered_write; +atomic_t netfs_n_wh_writethrough; +atomic_t netfs_n_wh_dio_write; +atomic_t netfs_n_wh_writepages; +atomic_t netfs_n_wh_copy_to_cache; +atomic_t netfs_n_wh_wstream_conflict; +atomic_t netfs_n_wh_upload; +atomic_t netfs_n_wh_upload_done; +atomic_t netfs_n_wh_upload_failed; +atomic_t netfs_n_wh_write; +atomic_t netfs_n_wh_write_done; +atomic_t netfs_n_wh_write_failed; +atomic_t netfs_n_wh_retry_write_req; +atomic_t netfs_n_wh_retry_write_subreq; +atomic_t netfs_n_wb_lock_skip; +atomic_t netfs_n_wb_lock_wait; +atomic_t netfs_n_folioq; + +int netfs_stats_show(struct seq_file *m, void *v) +{ + seq_printf(m, "Reads : DR=%u RA=%u RF=%u RS=%u WB=%u WBZ=%u\n", + atomic_read(&netfs_n_rh_dio_read), + atomic_read(&netfs_n_rh_readahead), + atomic_read(&netfs_n_rh_read_folio), + atomic_read(&netfs_n_rh_read_single), + atomic_read(&netfs_n_rh_write_begin), + atomic_read(&netfs_n_rh_write_zskip)); + seq_printf(m, "Writes : BW=%u WT=%u DW=%u WP=%u 2C=%u\n", + atomic_read(&netfs_n_wh_buffered_write), + atomic_read(&netfs_n_wh_writethrough), + atomic_read(&netfs_n_wh_dio_write), + atomic_read(&netfs_n_wh_writepages), + atomic_read(&netfs_n_wh_copy_to_cache)); + seq_printf(m, "ZeroOps: ZR=%u sh=%u sk=%u\n", + atomic_read(&netfs_n_rh_zero), + atomic_read(&netfs_n_rh_short_read), + atomic_read(&netfs_n_rh_write_zskip)); + seq_printf(m, "DownOps: DL=%u ds=%u df=%u di=%u\n", + atomic_read(&netfs_n_rh_download), + atomic_read(&netfs_n_rh_download_done), + atomic_read(&netfs_n_rh_download_failed), + atomic_read(&netfs_n_rh_download_instead)); + seq_printf(m, "CaRdOps: RD=%u rs=%u rf=%u\n", + atomic_read(&netfs_n_rh_read), + atomic_read(&netfs_n_rh_read_done), + atomic_read(&netfs_n_rh_read_failed)); + seq_printf(m, "UpldOps: UL=%u us=%u uf=%u\n", + atomic_read(&netfs_n_wh_upload), + atomic_read(&netfs_n_wh_upload_done), + atomic_read(&netfs_n_wh_upload_failed)); + seq_printf(m, "CaWrOps: WR=%u ws=%u wf=%u\n", + atomic_read(&netfs_n_wh_write), + atomic_read(&netfs_n_wh_write_done), + atomic_read(&netfs_n_wh_write_failed)); + seq_printf(m, "Retries: rq=%u rs=%u wq=%u ws=%u\n", + atomic_read(&netfs_n_rh_retry_read_req), + atomic_read(&netfs_n_rh_retry_read_subreq), + atomic_read(&netfs_n_wh_retry_write_req), + atomic_read(&netfs_n_wh_retry_write_subreq)); + seq_printf(m, "Objs : rr=%u sr=%u foq=%u wsc=%u\n", + atomic_read(&netfs_n_rh_rreq), + atomic_read(&netfs_n_rh_sreq), + atomic_read(&netfs_n_folioq), + atomic_read(&netfs_n_wh_wstream_conflict)); + seq_printf(m, "WbLock : skip=%u wait=%u\n", + atomic_read(&netfs_n_wb_lock_skip), + atomic_read(&netfs_n_wb_lock_wait)); + return fscache_stats_show(m); +} +EXPORT_SYMBOL(netfs_stats_show); -- cgit v1.3.1