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/jffs2/writev.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 fs/jffs2/writev.c (limited to 'fs/jffs2/writev.c') diff --git a/fs/jffs2/writev.c b/fs/jffs2/writev.c new file mode 100644 index 000000000..a1bda9dab --- /dev/null +++ b/fs/jffs2/writev.c @@ -0,0 +1,51 @@ +/* + * JFFS2 -- Journalling Flash File System, Version 2. + * + * Copyright © 2001-2007 Red Hat, Inc. + * + * Created by David Woodhouse + * + * For licensing information, see the file 'LICENCE' in this directory. + * + */ + +#include +#include +#include "nodelist.h" + +int jffs2_flash_direct_writev(struct jffs2_sb_info *c, const struct kvec *vecs, + unsigned long count, loff_t to, size_t *retlen) +{ + if (!jffs2_is_writebuffered(c)) { + if (jffs2_sum_active()) { + int res; + res = jffs2_sum_add_kvec(c, vecs, count, (uint32_t) to); + if (res) { + return res; + } + } + } + + return mtd_writev(c->mtd, vecs, count, to, retlen); +} + +int jffs2_flash_direct_write(struct jffs2_sb_info *c, loff_t ofs, size_t len, + size_t *retlen, const u_char *buf) +{ + int ret; + ret = mtd_write(c->mtd, ofs, len, retlen, buf); + + if (jffs2_sum_active()) { + struct kvec vecs[1]; + int res; + + vecs[0].iov_base = (unsigned char *) buf; + vecs[0].iov_len = len; + + res = jffs2_sum_add_kvec(c, vecs, 1, (uint32_t) ofs); + if (res) { + return res; + } + } + return ret; +} -- cgit v1.3.1