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 --- drivers/scsi/scsi_sysctl.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 drivers/scsi/scsi_sysctl.c (limited to 'drivers/scsi/scsi_sysctl.c') diff --git a/drivers/scsi/scsi_sysctl.c b/drivers/scsi/scsi_sysctl.c new file mode 100644 index 000000000..055a03a83 --- /dev/null +++ b/drivers/scsi/scsi_sysctl.c @@ -0,0 +1,38 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2003 Christoph Hellwig. + */ + +#include +#include +#include +#include + +#include "scsi_logging.h" +#include "scsi_priv.h" + + +static const struct ctl_table scsi_table[] = { + { .procname = "logging_level", + .data = &scsi_logging_level, + .maxlen = sizeof(scsi_logging_level), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_INT_MAX }, +}; + +static struct ctl_table_header *scsi_table_header; + +int __init scsi_init_sysctl(void) +{ + scsi_table_header = register_sysctl("dev/scsi", scsi_table); + if (!scsi_table_header) + return -ENOMEM; + return 0; +} + +void scsi_exit_sysctl(void) +{ + unregister_sysctl_table(scsi_table_header); +} -- cgit v1.3.1