mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
synced 2025-01-11 16:29:05 +00:00
6ec20aa2e5
At the moment, bad_kuap_fault() reports a fault only if a bad access
to userspace occurred while access to userspace was not granted.
But if a fault occurs for a write outside the allowed userspace
segment(s) that have been unlocked, bad_kuap_fault() fails to
detect it and the kernel loops forever in do_page_fault().
Fix it by checking that the accessed address is within the allowed
range.
Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f48244e9485ada0a304ed33ccbb8da271180c80d.1579866752.git.christophe.leroy@c-s.fr
78 lines
1.7 KiB
C
78 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _ASM_POWERPC_KUP_H_
|
|
#define _ASM_POWERPC_KUP_H_
|
|
|
|
#ifdef CONFIG_PPC64
|
|
#include <asm/book3s/64/kup-radix.h>
|
|
#endif
|
|
#ifdef CONFIG_PPC_8xx
|
|
#include <asm/nohash/32/kup-8xx.h>
|
|
#endif
|
|
#ifdef CONFIG_PPC_BOOK3S_32
|
|
#include <asm/book3s/32/kup.h>
|
|
#endif
|
|
|
|
#ifdef __ASSEMBLY__
|
|
#ifndef CONFIG_PPC_KUAP
|
|
.macro kuap_save_and_lock sp, thread, gpr1, gpr2, gpr3
|
|
.endm
|
|
|
|
.macro kuap_restore sp, current, gpr1, gpr2, gpr3
|
|
.endm
|
|
|
|
.macro kuap_check current, gpr
|
|
.endm
|
|
|
|
#endif
|
|
|
|
#else /* !__ASSEMBLY__ */
|
|
|
|
#include <asm/pgtable.h>
|
|
|
|
void setup_kup(void);
|
|
|
|
#ifdef CONFIG_PPC_KUEP
|
|
void setup_kuep(bool disabled);
|
|
#else
|
|
static inline void setup_kuep(bool disabled) { }
|
|
#endif /* CONFIG_PPC_KUEP */
|
|
|
|
#ifdef CONFIG_PPC_KUAP
|
|
void setup_kuap(bool disabled);
|
|
#else
|
|
static inline void setup_kuap(bool disabled) { }
|
|
static inline void allow_user_access(void __user *to, const void __user *from,
|
|
unsigned long size) { }
|
|
static inline void prevent_user_access(void __user *to, const void __user *from,
|
|
unsigned long size) { }
|
|
static inline bool
|
|
bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
|
|
{
|
|
return false;
|
|
}
|
|
#endif /* CONFIG_PPC_KUAP */
|
|
|
|
static inline void allow_read_from_user(const void __user *from, unsigned long size)
|
|
{
|
|
allow_user_access(NULL, from, size);
|
|
}
|
|
|
|
static inline void allow_write_to_user(void __user *to, unsigned long size)
|
|
{
|
|
allow_user_access(to, NULL, size);
|
|
}
|
|
|
|
static inline void prevent_read_from_user(const void __user *from, unsigned long size)
|
|
{
|
|
prevent_user_access(NULL, from, size);
|
|
}
|
|
|
|
static inline void prevent_write_to_user(void __user *to, unsigned long size)
|
|
{
|
|
prevent_user_access(to, NULL, size);
|
|
}
|
|
|
|
#endif /* !__ASSEMBLY__ */
|
|
|
|
#endif /* _ASM_POWERPC_KUP_H_ */
|