diff options
author | Andy Lutomirski <luto@amacapital.net> | 2015-02-12 15:01:14 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-12 18:54:12 -0800 |
commit | f56141e3e2d9aabf7e6b89680ab572c2cdbb2a24 (patch) | |
tree | 481e3d99bc1121ce75d505d340153b9d158e60c5 | |
parent | edc924e023ae2022fc29f1246e115c610c9abf38 (diff) |
all arches, signal: move restart_block to struct task_struct
If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target. This is because the
restart_block is held in the same memory allocation as the kernel stack.
Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.
Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.
It's also a decent simplification, since the restart code is more or less
identical on all architectures.
[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
84 files changed, 62 insertions, 194 deletions
diff --git a/arch/alpha/include/asm/thread_info.h b/arch/alpha/include/asm/thread_info.h index 48bbea6898b3..d5b98ab514bb 100644 --- a/arch/alpha/include/asm/thread_info.h +++ b/arch/alpha/include/asm/thread_info.h @@ -27,8 +27,6 @@ struct thread_info { int bpt_nsaved; unsigned long bpt_addr[2]; /* breakpoint handling */ unsigned int bpt_insn[2]; - - struct restart_block restart_block; }; /* @@ -40,9 +38,6 @@ struct thread_info { .exec_domain = &default_exec_domain, \ .addr_limit = KERNEL_DS, \ .preempt_count = INIT_PREEMPT_COUNT, \ - .restart_block = { \ - .fn = do_no_restart_syscall, \ - }, \ } #define init_thread_info (init_thread_union.thread_info) diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c index 6cec2881acbf..8dbfb15f1745 100644 --- a/arch/alpha/kernel/signal.c +++ b/arch/alpha/kernel/signal.c @@ -150,7 +150,7 @@ restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) struct switch_stack *sw = (struct switch_stack *)regs - 1; long i, err = __get_user(regs->pc, &sc->sc_pc); - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; sw->r26 = (unsigned long) ret_from_sys_call; diff --git a/arch/arc/include/asm/thread_info.h b/arch/arc/include/asm/thread_info.h index 02bc5ec0fb2e..1163a1838ac1 100644 --- a/arch/arc/include/asm/thread_info.h +++ b/arch/arc/include/asm/thread_info.h @@ -46,7 +46,6 @@ struct thread_info { struct exec_domain *exec_domain;/* execution domain */ __u32 cpu; /* current CPU */ unsigned long thr_ptr; /* TLS ptr */ - struct restart_block restart_block; }; /* @@ -62,9 +61,6 @@ struct thread_info { .cpu = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ .addr_limit = KERNEL_DS, \ - .restart_block = { \ - .fn = do_no_restart_syscall, \ - }, \ } #define init_thread_info (init_thread_union.thread_info) diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c index cb3142a2d40b..114234e83caa 100644 --- a/arch/arc/kernel/signal.c +++ b/arch/arc/kernel/signal.c @@ -104,7 +104,7 @@ SYSCALL_DEFINE0(rt_sigreturn) struct pt_regs *regs = current_pt_regs(); /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; /* Since we stacked the signal on a word boundary, * then 'sp' should be word aligned here. If it's diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index d890e41f5520..72812a1f3d1c 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -68,7 +68,6 @@ struct thread_info { #ifdef CONFIG_ARM_THUMBEE unsigned long thumbee_state; /* ThumbEE Handler Base register */ #endif - struct restart_block restart_block; }; #define INIT_THREAD_INFO(tsk) \ @@ -81,9 +80,6 @@ struct thread_info { .cpu_domain = domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \ domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \ domain_val(DOMAIN_IO, DOMAIN_CLIENT), \ - .restart_block = { \ - .fn = do_no_restart_syscall, \ - }, \ } #define init_thread_info (init_thread_union.thread_info) diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index 8aa6f1b87c9e..023ac905e4c3 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -191,7 +191,7 @@ asmlinkage int sys_sigreturn(struct pt_regs *regs) struct sigframe __user *frame; /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; /* * Since we stacked the signal on a 64-bit boundary, @@ -221,7 +221,7 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) struct rt_sigframe __user *frame; /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; /* * Since we stacked the signal on a 64-bit boundary, diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index 459bf8e53208..702e1e6a0d80 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -48,7 +48,6 @@ struct thread_info { mm_segment_t addr_limit; /* address limit */ struct task_struct *task; /* main task structure */ struct exec_domain *exec_domain; /* execution domain */ - struct restart_block restart_block; int preempt_count; /* 0 => preemptable, <0 => bug */ int cpu; /* cpu */ }; @@ -60,9 +59,6 @@ struct thread_info { .flags = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ .addr_limit = KERNEL_DS, \ - .restart_block = { \ - .fn = do_no_restart_syscall, \ - }, \ } #define init_thread_info (init_thread_union.thread_info) diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 6fa792137eda..660ccf9f7524 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -131,7 +131,7 @@ asmlinkage long sys_rt_sigreturn(struct pt_regs *regs) struct rt_sigframe __user *frame; /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; /* * Since we stacked the signal on a 128-bit boundary, then 'sp' should diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c index e299de396e9b..c20a300e2213 100644 --- a/arch/arm64/kernel/signal32.c +++ b/arch/arm64/kernel/signal32.c @@ -347,7 +347,7 @@ asmlinkage int compat_sys_sigreturn(struct pt_regs *regs) struct compat_sigframe __user *frame; /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; /* * Since we stacked the signal on a 64-bit boundary, @@ -381,7 +381,7 @@ asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs) struct compat_rt_sigframe __user *frame; /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; /* * Since we stacked the signal on a 64-bit boundary, diff --git a/arch/avr32/include/asm/thread_info.h b/arch/avr32/include/asm/thread_info.h index a978f3fe7c25..d56afa99a514 100644 --- a/arch/avr32/include/asm/thread_info.h +++ b/arch/avr32/include/asm/thread_info.h @@ -30,7 +30,6 @@ struct thread_info { saved by debug handler when setting up trampoline */ - struct restart_block restart_block; __u8 supervisor_stack[0]; }; @@ -41,9 +40,6 @@ struct thread_info { .flags = 0, \ .cpu = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ - .restart_block = { \ - .fn = do_no_restart_syscall \ - } \ } #define init_thread_info (init_thread_union.thread_info) diff --git a/arch/avr32/kernel/asm-offsets.c b/arch/avr32/kernel/asm-offsets.c index d6a8193a1d2f..e41c84516e5d 100644 --- a/arch/avr32/kernel/asm-offsets.c +++ b/arch/avr32/kernel/asm-offsets.c @@ -18,7 +18,6 @@ void foo(void) OFFSET(TI_preempt_count, thread_info, preempt_count); OFFSET(TI_rar_saved, thread_info, rar_saved); OFFSET(TI_rsr_saved, thread_info, rsr_saved); - OFFSET(TI_restart_block, thread_info, restart_block); BLANK(); OFFSET(TSK_active_mm, task_struct, active_mm); BLANK(); diff --git a/arch/avr32/kernel/signal.c b/arch/avr32/kernel/signal.c index d309fbcc3bd6..8f1c63b9b983 100644 --- a/arch/avr32/kernel/signal.c +++ b/arch/avr32/kernel/signal.c @@ -69,7 +69,7 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) sigset_t set; /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; frame = (struct rt_sigframe __user *)regs->sp; pr_debug("SIG return: frame = %p\n", frame); diff --git a/arch/blackfin/include/asm/thread_info.h b/arch/blackfin/include/asm/thread_info.h index 55f473bdad36..57c3a8bd583d 100644 --- a/arch/blackfin/include/asm/thread_info.h +++ b/arch/blackfin/include/asm/thread_info.h @@ -42,7 +42,6 @@ struct thread_info { int cpu; /* cpu we're on */ int preempt_count; /* 0 => preemptable, <0 => BUG */ mm_segment_t addr_limit; /* address limit */ - struct restart_block restart_block; #ifndef CONFIG_SMP struct l1_scratch_task_info l1_task_info; #endif @@ -58,9 +57,6 @@ struct thread_info { .flags = 0, \ .cpu = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ - .restart_block = { \ - .fn = do_no_restart_syscall, \ - }, \ } #define init_thread_info (init_thread_union.thread_info) #define init_stack (init_thread_union.stack) diff --git a/arch/blackfin/kernel/signal.c b/arch/blackfin/kernel/signal.c index ef275571d885..f2a8b5493bd3 100644 --- a/arch/blackfin/kernel/signal.c +++ b/arch/blackfin/kernel/signal.c @@ -44,7 +44,7 @@ rt_restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *p int err = 0; /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; #define RESTORE(x) err |= __get_user(regs->x, &sc->sc_##x) diff --git a/arch/c6x/include/asm/thread_info.h b/arch/c6x/include/asm/thread_info.h index d4e9ef87076d..584e253f3217 100644 --- a/arch/c6x/include/asm/thread_info.h +++ b/arch/c6x/include/asm/thread_info.h @@ -45,7 +45,6 @@ struct thread_info { int cpu; /* cpu we're on */ int preempt_count; /* 0 = preemptable, <0 = BUG */ mm_segment_t addr_limit; /* thread address space */ - struct restart_block restart_block; }; /* @@ -61,9 +60,6 @@ struct thread_info { .cpu = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ .addr_limit = KERNEL_DS, \ - .restart_block = { \ - .fn = do_no_restart_syscall, \ - }, \ } #define init_thread_info (init_thread_union.thread_info) diff --git a/arch/c6x/kernel/signal.c b/arch/c6x/kernel/signal.c index fe68226f6c4d..3c4bb5a5c382 100644 --- a/arch/c6x/kernel/signal.c +++ b/arch/c6x/kernel/signal.c @@ -68,7 +68,7 @@ asmlinkage int do_rt_sigreturn(struct pt_regs *regs) sigset_t set; /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; /* * Since we stacked the signal on a dword boundary, diff --git a/arch/cris/arch-v10/kernel/signal.c b/arch/cris/arch-v10/kernel/signal.c index 9b32d338838b..74d7ba35120d 100644 --- a/arch/cris/arch-v10/kernel/signal.c +++ b/arch/cris/arch-v10/kernel/signal.c @@ -67,7 +67,7 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) unsigned long old_usp; /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; /* restore the regs from &sc->regs (same as sc, since regs is first) * (sc is already checked for VERIFY_READ since the sigframe was diff --git a/arch/cris/arch-v32/kernel/signal.c b/arch/cris/arch-v32/kernel/signal.c index 78ce3b1c9bcb..870e3e069318 100644 --- a/arch/cris/arch-v32/kernel/signal.c +++ b/arch/cris/arch-v32/kernel/signal.c @@ -59,7 +59,7 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) unsigned long old_usp; /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; /* * Restore the registers from &sc->regs. sc is already checked diff --git a/arch/cris/include/asm/thread_info.h b/arch/cris/include/asm/thread_info.h index 55dede18c032..7286db5ed90e 100644 --- a/arch/cris/include/asm/thread_info.h +++ b/arch/cris/include/asm/thread_info.h @@ -38,7 +38,6 @@ struct thread_info { 0-0xBFFFFFFF for user-thead 0-0xFFFFFFFF for kernel-thread */ - struct restart_block restart_block; __u8 supervisor_stack[0]; }; @@ -56,9 +55,6 @@ struct thread_info { .cpu = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ .addr_limit = KERNEL_DS, \ - .restart_block = { \ - .fn = do_no_restart_syscall, \ - }, \ } #define init_thread_info (init_thread_union.thread_info) diff --git a/arch/frv/include/asm/thread_info.h b/arch/frv/include/asm/thread_info.h index af29e17c0181..6b917f1c2955 100644 --- a/arch/frv/include/asm/thread_info.h +++ b/arch/frv/include/asm/thread_info.h @@ -41,7 +41,6 @@ struct thread_info { * 0-0xBFFFFFFF for user-thead * 0-0xFFFFFFFF for kernel-thread */ - struct restart_block restart_block; __u8 supervisor_stack[0]; }; @@ -65,9 +64,6 @@ struct thread_info { .cpu = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ .addr_limit = KERNEL_DS, \ - .restart_block = { \ - .fn = do_no_restart_syscall, \ - }, \ } #define init_thread_info (init_thread_union.thread_info) diff --git a/arch/frv/kernel/asm-offsets.c b/arch/frv/kernel/asm-offsets.c index 9de96843a278..446e89d500cc 100644 --- a/arch/frv/kernel/asm-offsets.c +++ b/ |