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 --- include/uapi/mtd/inftl-user.h | 92 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) create mode 100644 include/uapi/mtd/inftl-user.h (limited to 'include/uapi/mtd/inftl-user.h') diff --git a/include/uapi/mtd/inftl-user.h b/include/uapi/mtd/inftl-user.h new file mode 100644 index 000000000..8d5044e32 --- /dev/null +++ b/include/uapi/mtd/inftl-user.h @@ -0,0 +1,92 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * Parts of INFTL headers shared with userspace + * + */ + +#ifndef __MTD_INFTL_USER_H__ +#define __MTD_INFTL_USER_H__ + +#include + +#define OSAK_VERSION 0x5120 +#define PERCENTUSED 98 + +#define SECTORSIZE 512 + +/* Block Control Information */ + +struct inftl_bci { + __u8 ECCsig[6]; + __u8 Status; + __u8 Status1; +} __attribute__((packed)); + +struct inftl_unithead1 { + __u16 virtualUnitNo; + __u16 prevUnitNo; + __u8 ANAC; + __u8 NACs; + __u8 parityPerField; + __u8 discarded; +} __attribute__((packed)); + +struct inftl_unithead2 { + __u8 parityPerField; + __u8 ANAC; + __u16 prevUnitNo; + __u16 virtualUnitNo; + __u8 NACs; + __u8 discarded; +} __attribute__((packed)); + +struct inftl_unittail { + __u8 Reserved[4]; + __u16 EraseMark; + __u16 EraseMark1; +} __attribute__((packed)); + +union inftl_uci { + struct inftl_unithead1 a; + struct inftl_unithead2 b; + struct inftl_unittail c; +}; + +struct inftl_oob { + struct inftl_bci b; + union inftl_uci u; +}; + + +/* INFTL Media Header */ + +struct INFTLPartition { + __u32 virtualUnits; + __u32 firstUnit; + __u32 lastUnit; + __u32 flags; + __u32 spareUnits; + __u32 Reserved0; + __u32 Reserved1; +} __attribute__((packed)); + +struct INFTLMediaHeader { + char bootRecordID[8]; + __u32 NoOfBootImageBlocks; + __u32 NoOfBinaryPartitions; + __u32 NoOfBDTLPartitions; + __u32 BlockMultiplierBits; + __u32 FormatFlags; + __u32 OsakVersion; + __u32 PercentUsed; + struct INFTLPartition Partitions[4]; +} __attribute__((packed)); + +/* Partition flag types */ +#define INFTL_BINARY 0x20000000 +#define INFTL_BDTL 0x40000000 +#define INFTL_LAST 0x80000000 + +#endif /* __MTD_INFTL_USER_H__ */ + + -- cgit v1.3.1