Commit 6c51e67b authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-syscall-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull syscall updates from Ingo Molnar:
 "Improve the security of set_fs(): we now check the address limit on a
  number of key platforms (x86, arm, arm64) before returning to
  user-space - without adding overhead to the typical system call fast
  path"

* 'x86-syscall-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arm64/syscalls: Check address limit on user-mode return
  arm/syscalls: Check address limit on user-mode return
  x86/syscalls: Check address limit on user-mode return
parents e0a195b5 cf7de27a

arch/arm/include/asm/thread_info.h

+9 −6
Original line number Diff line number Diff line
@@ -139,10 +139,11 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *, 
#define TIF_NEED_RESCHED	1	/* rescheduling necessary */

#define TIF_NOTIFY_RESUME	2	/* callback before returning to user */

#define TIF_UPROBE		3	/* breakpointed or singlestepping */

#define TIF_SYSCALL_TRACE	4	/* syscall trace active */

#define TIF_SYSCALL_AUDIT	5	/* syscall auditing active */

#define TIF_SYSCALL_TRACEPOINT	6	/* syscall tracepoint instrumentation */

#define TIF_SECCOMP		7	/* seccomp syscall filtering active */

#define TIF_FSCHECK		4	/* Check FS is USER_DS on return */

#define TIF_SYSCALL_TRACE	5	/* syscall trace active */

#define TIF_SYSCALL_AUDIT	6	/* syscall auditing active */

#define TIF_SYSCALL_TRACEPOINT	7	/* syscall tracepoint instrumentation */

#define TIF_SECCOMP		8	/* seccomp syscall filtering active */



#define TIF_NOHZ		12	/* in adaptive nohz mode */

#define TIF_USING_IWMMXT	17
@@ -153,6 +154,7 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *, 
#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)

#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)

#define _TIF_UPROBE		(1 << TIF_UPROBE)

#define _TIF_FSCHECK		(1 << TIF_FSCHECK)

#define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)

#define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)

#define _TIF_SYSCALL_TRACEPOINT	(1 << TIF_SYSCALL_TRACEPOINT)
@@ -167,7 +169,8 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *, 
 * Change these and you break ASM code in entry-common.S

 */

#define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING |	\

				 _TIF_NOTIFY_RESUME | _TIF_UPROBE)

				 _TIF_NOTIFY_RESUME | _TIF_UPROBE |	\

				 _TIF_FSCHECK)



#endif /* __KERNEL__ */

#endif /* __ASM_ARM_THREAD_INFO_H */

arch/arm/include/asm/uaccess.h

+2 −0
Original line number Diff line number Diff line
@@ -70,6 +70,8 @@ static inline void set_fs(mm_segment_t fs) 
{

	current_thread_info()->addr_limit = fs;

	modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);

	/* On user-mode return, check fs is correct */

	set_thread_flag(TIF_FSCHECK);

}



#define segment_eq(a, b)	((a) == (b))

arch/arm/kernel/entry-common.S

+7 −2
Original line number Diff line number Diff line
@@ -41,7 +41,9 @@ ret_fast_syscall: 
 UNWIND(.cantunwind	)

	disable_irq_notrace			@ disable interrupts

	ldr	r1, [tsk, #TI_FLAGS]		@ re-check for syscall tracing

	tst	r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK

	tst	r1, #_TIF_SYSCALL_WORK

	bne	fast_work_pending

	tst	r1, #_TIF_WORK_MASK

	bne	fast_work_pending



	/* perform architecture specific actions before user return */
@@ -67,12 +69,15 @@ ret_fast_syscall: 
	str	r0, [sp, #S_R0 + S_OFF]!	@ save returned r0

	disable_irq_notrace			@ disable interrupts

	ldr	r1, [tsk, #TI_FLAGS]		@ re-check for syscall tracing

	tst	r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK

	tst	r1, #_TIF_SYSCALL_WORK

	bne	fast_work_pending

	tst	r1, #_TIF_WORK_MASK

	beq	no_work_pending

 UNWIND(.fnend		)

ENDPROC(ret_fast_syscall)



	/* Slower path - fall through to work_pending */

fast_work_pending:

#endif



	tst	r1, #_TIF_SYSCALL_WORK

arch/arm/kernel/signal.c

+5 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/uaccess.h>

#include <linux/tracehook.h>

#include <linux/uprobes.h>

#include <linux/syscalls.h>



#include <asm/elf.h>

#include <asm/cacheflush.h>
@@ -613,6 +614,10 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall) 
	 * Update the trace code with the current status.

	 */

	trace_hardirqs_off();



	/* Check valid user FS if needed */

	addr_limit_user_check();



	do {

		if (likely(thread_flags & _TIF_NEED_RESCHED)) {

			schedule();

arch/arm64/include/asm/thread_info.h

+3 −1
Original line number Diff line number Diff line
@@ -86,6 +86,7 @@ struct thread_info { 
#define TIF_NOTIFY_RESUME	2	/* callback before returning to user */

#define TIF_FOREIGN_FPSTATE	3	/* CPU's FP state is not current's */

#define TIF_UPROBE		4	/* uprobe breakpoint or singlestep */

#define TIF_FSCHECK		5	/* Check FS is USER_DS on return */

#define TIF_NOHZ		7

#define TIF_SYSCALL_TRACE	8

#define TIF_SYSCALL_AUDIT	9
@@ -107,11 +108,12 @@ struct thread_info { 
#define _TIF_SYSCALL_TRACEPOINT	(1 << TIF_SYSCALL_TRACEPOINT)

#define _TIF_SECCOMP		(1 << TIF_SECCOMP)

#define _TIF_UPROBE		(1 << TIF_UPROBE)

#define _TIF_FSCHECK		(1 << TIF_FSCHECK)

#define _TIF_32BIT		(1 << TIF_32BIT)



#define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \

				 _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \

				 _TIF_UPROBE)

				 _TIF_UPROBE | _TIF_FSCHECK)



#define _TIF_SYSCALL_WORK	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \

				 _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \

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