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/batman-adv/bitarray.h | 56 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 net/batman-adv/bitarray.h (limited to 'net/batman-adv/bitarray.h') diff --git a/net/batman-adv/bitarray.h b/net/batman-adv/bitarray.h new file mode 100644 index 000000000..2b9f5dbb3 --- /dev/null +++ b/net/batman-adv/bitarray.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) B.A.T.M.A.N. contributors: + * + * Simon Wunderlich, Marek Lindner + */ + +#ifndef _NET_BATMAN_ADV_BITARRAY_H_ +#define _NET_BATMAN_ADV_BITARRAY_H_ + +#include "main.h" + +#include +#include +#include +#include + +/** + * batadv_test_bit() - check if bit is set in the current window + * + * @seq_bits: pointer to the sequence number bitmap of received packets + * @last_seqno: latest sequence number in seq_bits + * @curr_seqno: sequence number to test for + * + * Return: true if the corresponding bit in the given seq_bits indicates true + * and curr_seqno is within range of last_seqno. Otherwise returns false. + */ +static inline bool batadv_test_bit(const unsigned long *seq_bits, + u32 last_seqno, u32 curr_seqno) +{ + s32 diff; + + diff = last_seqno - curr_seqno; + if (diff < 0 || diff >= BATADV_TQ_LOCAL_WINDOW_SIZE) + return false; + return test_bit(diff, seq_bits) != 0; +} + +/** + * batadv_set_bit() - Turn corresponding bit on, so we can remember that we got + * the packet + * @seq_bits: bitmap of the packet receive window + * @n: relative sequence number of newly received packet + */ +static inline void batadv_set_bit(unsigned long *seq_bits, s32 n) +{ + /* if too old, just drop it */ + if (n < 0 || n >= BATADV_TQ_LOCAL_WINDOW_SIZE) + return; + + set_bit(n, seq_bits); /* turn the position on */ +} + +bool batadv_bit_get_packet(void *priv, unsigned long *seq_bits, + s32 seq_num_diff, int set_mark); + +#endif /* _NET_BATMAN_ADV_BITARRAY_H_ */ -- cgit v1.3.1