Commit b75f9472 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'hardening-v6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux 

Pull hardening fixes from Kees Cook:

 - Remove invalid tty __counted_by annotation (Nathan Chancellor)

 - Add missing MODULE_DESCRIPTION()s for KUnit string tests (Jeff
   Johnson)

 - Remove non-functional per-arch kstack entropy filtering

* tag 'hardening-v6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  tty: mxser: Remove __counted_by from mxser_board.ports[]
  randomize_kstack: Remove non-functional per-arch entropy filtering
  string: kunit: add missing MODULE_DESCRIPTION() macros
parents 093d9603 1c07c9be

arch/arm64/kernel/syscall.c

+7 −9
Original line number Diff line number Diff line
@@ -53,17 +53,15 @@ static void invoke_syscall(struct pt_regs *regs, unsigned int scno, 
	syscall_set_return_value(current, regs, 0, ret);



	/*

	 * Ultimately, this value will get limited by KSTACK_OFFSET_MAX(),

	 * but not enough for arm64 stack utilization comfort. To keep

	 * reasonable stack head room, reduce the maximum offset to 9 bits.

	 * This value will get limited by KSTACK_OFFSET_MAX(), which is 10

	 * bits. The actual entropy will be further reduced by the compiler

	 * when applying stack alignment constraints: the AAPCS mandates a

	 * 16-byte aligned SP at function boundaries, which will remove the

	 * 4 low bits from any entropy chosen here.

	 *

	 * The actual entropy will be further reduced by the compiler when

	 * applying stack alignment constraints: the AAPCS mandates a

	 * 16-byte (i.e. 4-bit) aligned SP at function boundaries.

	 *

	 * The resulting 5 bits of entropy is seen in SP[8:4].

	 * The resulting 6 bits of entropy is seen in SP[9:4].

	 */

	choose_random_kstack_offset(get_random_u16() & 0x1FF);

	choose_random_kstack_offset(get_random_u16());

}



static inline bool has_syscall_work(unsigned long flags)

arch/s390/include/asm/entry-common.h

+1 −1
Original line number Diff line number Diff line
@@ -54,7 +54,7 @@ static __always_inline void arch_exit_to_user_mode(void) 
static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,

						  unsigned long ti_work)

{

	choose_random_kstack_offset(get_tod_clock_fast() & 0xff);

	choose_random_kstack_offset(get_tod_clock_fast());

}



#define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare

arch/x86/include/asm/entry-common.h

+6 −9
Original line number Diff line number Diff line
@@ -73,19 +73,16 @@ static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs, 
#endif



	/*

	 * Ultimately, this value will get limited by KSTACK_OFFSET_MAX(),

	 * but not enough for x86 stack utilization comfort. To keep

	 * reasonable stack head room, reduce the maximum offset to 8 bits.

	 *

	 * The actual entropy will be further reduced by the compiler when

	 * applying stack alignment constraints (see cc_stack_align4/8 in

	 * This value will get limited by KSTACK_OFFSET_MAX(), which is 10

	 * bits. The actual entropy will be further reduced by the compiler

	 * when applying stack alignment constraints (see cc_stack_align4/8 in

	 * arch/x86/Makefile), which will remove the 3 (x86_64) or 2 (ia32)

	 * low bits from any entropy chosen here.

	 *

	 * Therefore, final stack offset entropy will be 5 (x86_64) or

	 * 6 (ia32) bits.

	 * Therefore, final stack offset entropy will be 7 (x86_64) or

	 * 8 (ia32) bits.

	 */

	choose_random_kstack_offset(rdtsc() & 0xFF);

	choose_random_kstack_offset(rdtsc());

}

#define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare

drivers/tty/mxser.c

+1 −1
Original line number Diff line number Diff line
@@ -288,7 +288,7 @@ struct mxser_board { 
	enum mxser_must_hwid must_hwid;

	speed_t max_baud;



	struct mxser_port ports[] __counted_by(nports);

	struct mxser_port ports[] /* __counted_by(nports) */;

};



static DECLARE_BITMAP(mxser_boards, MXSER_BOARDS);

lib/string_helpers_kunit.c

+1 −0
Original line number Diff line number Diff line
@@ -625,4 +625,5 @@ static struct kunit_suite string_helpers_test_suite = { 


kunit_test_suites(&string_helpers_test_suite);



MODULE_DESCRIPTION("Test cases for string helpers module");

MODULE_LICENSE("Dual BSD/GPL");