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author | Andy Lutomirski <luto@amacapital.net> | 2015-02-12 15:01:14 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-12 18:54:12 -0800 |
commit | f56141e3e2d9aabf7e6b89680ab572c2cdbb2a24 (patch) | |
tree | 481e3d99bc1121ce75d505d340153b9d158e60c5 /arch/sparc | |
parent | edc924e023ae2022fc29f1246e115c610c9abf38 (diff) | |
download | op-kernel-dev-f56141e3e2d9aabf7e6b89680ab572c2cdbb2a24.zip op-kernel-dev-f56141e3e2d9aabf7e6b89680ab572c2cdbb2a24.tar.gz |
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>
Diffstat (limited to 'arch/sparc')
-rw-r--r-- | arch/sparc/include/asm/thread_info_32.h | 6 | ||||
-rw-r--r-- | arch/sparc/include/asm/thread_info_64.h | 12 | ||||
-rw-r--r-- | arch/sparc/kernel/signal32.c | 4 | ||||
-rw-r--r-- | arch/sparc/kernel/signal_32.c | 2 | ||||
-rw-r--r-- | arch/sparc/kernel/signal_64.c | 2 | ||||
-rw-r--r-- | arch/sparc/kernel/traps_64.c | 2 |
6 files changed, 7 insertions, 21 deletions
diff --git a/arch/sparc/include/asm/thread_info_32.h b/arch/sparc/include/asm/thread_info_32.h index 025c984..fd7bd0a 100644 --- a/arch/sparc/include/asm/thread_info_32.h +++ b/arch/sparc/include/asm/thread_info_32.h @@ -47,8 +47,6 @@ struct thread_info { struct reg_window32 reg_window[NSWINS]; /* align for ldd! */ unsigned long rwbuf_stkptrs[NSWINS]; unsigned long w_saved; - - struct restart_block restart_block; }; /* @@ -62,9 +60,6 @@ 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) @@ -103,7 +98,6 @@ register struct thread_info *current_thread_info_reg asm("g6"); #define TI_REG_WINDOW 0x30 #define TI_RWIN_SPTRS 0x230 #define TI_W_SAVED 0x250 -/* #define TI_RESTART_BLOCK 0x25n */ /* Nobody cares */ /* * thread information flag bit numbers diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h index 798f027..ff45516 100644 --- a/arch/sparc/include/asm/thread_info_64.h +++ b/arch/sparc/include/asm/thread_info_64.h @@ -58,8 +58,6 @@ struct thread_info { unsigned long gsr[7]; unsigned long xfsr[7]; - struct restart_block restart_block; - struct pt_regs *kern_una_regs; unsigned int kern_una_insn; @@ -92,10 +90,9 @@ struct thread_info { #define TI_RWIN_SPTRS 0x000003c8 #define TI_GSR 0x00000400 #define TI_XFSR 0x00000438 -#define TI_RESTART_BLOCK 0x00000470 -#define TI_KUNA_REGS 0x000004a0 -#define TI_KUNA_INSN 0x000004a8 -#define TI_FPREGS 0x000004c0 +#define TI_KUNA_REGS 0x00000470 +#define TI_KUNA_INSN 0x00000478 +#define TI_FPREGS 0x00000480 /* We embed this in the uppermost byte of thread_info->flags */ #define FAULT_CODE_WRITE 0x01 /* Write access, implies D-TLB */ @@ -124,9 +121,6 @@ struct thread_info { .current_ds = ASI_P, \ .exec_domain = &default_exec_domain, \ .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/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c index 62deba7..4eed773 100644 --- a/arch/sparc/kernel/signal32.c +++ b/arch/sparc/kernel/signal32.c @@ -150,7 +150,7 @@ void do_sigreturn32(struct pt_regs *regs) int err, i; /* 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; synchronize_user_stack(); @@ -235,7 +235,7 @@ asmlinkage void do_rt_sigreturn32(struct pt_regs *regs) int err, i; /* 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; synchronize_user_stack(); regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL; diff --git a/arch/sparc/kernel/signal_32.c b/arch/sparc/kernel/signal_32.c index 9ee72fc..52aa5e4 100644 --- a/arch/sparc/kernel/signal_32.c +++ b/arch/sparc/kernel/signal_32.c @@ -70,7 +70,7 @@ asmlinkage void do_sigreturn(struct pt_regs *regs) int err; /* 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; synchronize_user_stack(); diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c index 1a69998..d88beff4 100644 --- a/arch/sparc/kernel/signal_64.c +++ b/arch/sparc/kernel/signal_64.c @@ -254,7 +254,7 @@ void do_rt_sigreturn(struct pt_regs *regs) int err; /* 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; synchronize_user_stack (); sf = (struct rt_signal_frame __user *) diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c index 981a769..a27651e 100644 --- a/arch/sparc/kernel/traps_64.c +++ b/arch/sparc/kernel/traps_64.c @@ -2730,8 +2730,6 @@ void __init trap_init(void) TI_NEW_CHILD != offsetof(struct thread_info, new_child) || TI_CURRENT_DS != offsetof(struct thread_info, current_ds) || - TI_RESTART_BLOCK != offsetof(struct thread_info, - restart_block) || TI_KUNA_REGS != offsetof(struct thread_info, kern_una_regs) || TI_KUNA_INSN != offsetof(struct thread_info, |