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| author | Ali Ahmet Memis <ali@iusegentoo.com> | 2026-08-21 01:45:27 +0000 |
|---|---|---|
| committer | Stafford Horne <shorne@gmail.com> | 2026-08-29 07:32:26 +0100 |
| commit | 78004e9a87f240df03e2f73120d291763c32e0a7 (patch) | |
| tree | 137c22dd795222931b9d2bf2501d37cd766741aa /fs/gfs2/glops.h | |
| download | linux-stable-78004e9a87f240df03e2f73120d291763c32e0a7.tar.gz linux-stable-78004e9a87f240df03e2f73120d291763c32e0a7.zip | |
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>
Diffstat (limited to 'fs/gfs2/glops.h')
| -rw-r--r-- | fs/gfs2/glops.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/fs/gfs2/glops.h b/fs/gfs2/glops.h new file mode 100644 index 000000000..934142379 --- /dev/null +++ b/fs/gfs2/glops.h @@ -0,0 +1,28 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. + */ + +#ifndef __GLOPS_DOT_H__ +#define __GLOPS_DOT_H__ + +#include "incore.h" + +extern struct workqueue_struct *gfs2_freeze_wq; + +extern const struct gfs2_glock_operations gfs2_meta_glops; +extern const struct gfs2_glock_operations gfs2_inode_glops; +extern const struct gfs2_glock_operations gfs2_rgrp_glops; +extern const struct gfs2_glock_operations gfs2_freeze_glops; +extern const struct gfs2_glock_operations gfs2_iopen_glops; +extern const struct gfs2_glock_operations gfs2_flock_glops; +extern const struct gfs2_glock_operations gfs2_nondisk_glops; +extern const struct gfs2_glock_operations gfs2_quota_glops; +extern const struct gfs2_glock_operations gfs2_journal_glops; +extern const struct gfs2_glock_operations *gfs2_glops_list[]; + +int gfs2_inode_metasync(struct gfs2_glock *gl); +void gfs2_ail_flush(struct gfs2_glock *gl, bool fsync); + +#endif /* __GLOPS_DOT_H__ */ |