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From: Oleg Nesterov <oleg@redhat.com>
To: Frederic Weisbecker <fweisbec@gmail.com>,
	Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Amnon Shiloh <u3557@miso.sublimeip.com>, linux-kernel@vger.kernel.org
Subject: [PATCH] arch_check_bp_in_kernelspace: fix the range check
Date: Fri, 9 Nov 2012 19:29:43 +0100	[thread overview]
Message-ID: <20121109182943.GA2789@redhat.com> (raw)

arch_check_bp_in_kernelspace() tries to avoid the overflow and does 2
TASK_SIZE checks but it needs OR, not AND. Consider va = TASK_SIZE -1
and len = 2 case.

Note: TASK_SIZE doesn't look right at least on x86, I think it should
be replaced by TASK_SIZE_MAX.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>

--- x/arch/arm64/kernel/hw_breakpoint.c
+++ x/arch/arm64/kernel/hw_breakpoint.c
@@ -293,7 +293,7 @@ int arch_check_bp_in_kernelspace(struct 
 	va = info->address;
 	len = get_hbp_len(info->ctrl.len);
 
-	return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
+	return (va >= TASK_SIZE) || ((va + len - 1) >= TASK_SIZE);
 }
 
 /*
--- x/arch/arm/kernel/hw_breakpoint.c
+++ x/arch/arm/kernel/hw_breakpoint.c
@@ -464,7 +464,7 @@ int arch_check_bp_in_kernelspace(struct 
 	va = info->address;
 	len = get_hbp_len(info->ctrl.len);
 
-	return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
+	return (va >= TASK_SIZE) || ((va + len - 1) >= TASK_SIZE);
 }
 
 /*
--- x/arch/sh/kernel/hw_breakpoint.c
+++ x/arch/sh/kernel/hw_breakpoint.c
@@ -132,7 +132,7 @@ int arch_check_bp_in_kernelspace(struct 
 	va = info->address;
 	len = get_hbp_len(info->len);
 
-	return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
+	return (va >= TASK_SIZE) || ((va + len - 1) >= TASK_SIZE);
 }
 
 int arch_bp_generic_fields(int sh_len, int sh_type,
--- x/arch/x86/kernel/hw_breakpoint.c
+++ x/arch/x86/kernel/hw_breakpoint.c
@@ -200,7 +200,7 @@ int arch_check_bp_in_kernelspace(struct 
 	va = info->address;
 	len = get_hbp_len(info->len);
 
-	return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
+	return (va >= TASK_SIZE) || ((va + len - 1) >= TASK_SIZE);
 }
 
 int arch_bp_generic_fields(int x86_len, int x86_type,


             reply	other threads:[~2012-11-09 18:29 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-09 18:29 Oleg Nesterov [this message]
2012-11-09 18:30 ` [PATCH] arch_check_bp_in_kernelspace: fix the range check Oleg Nesterov
2012-11-19 17:47   ` Oleg Nesterov
2012-11-19 18:25     ` Steven Rostedt
2012-11-20 10:33       ` u3557
2012-11-20 15:48       ` Oleg Nesterov
2012-11-20 15:55         ` Steven Rostedt
2012-11-20 18:32         ` Oleg Nesterov
2012-11-20 23:16           ` u3557
2012-11-21 14:16             ` Oleg Nesterov
2012-11-21 17:30               ` Amnon Shiloh
2012-11-22 16:12                 ` vdso && cr (Was: arch_check_bp_in_kernelspace: fix the range check) Oleg Nesterov
2012-11-22 20:57                   ` Pavel Emelyanov
2012-11-23  0:20                     ` vdso && cr (Was: arch_check_bp_in_kernelspace: fix the range Amnon Shiloh
2012-11-23 17:45                       ` Oleg Nesterov
2012-11-24 12:47                         ` Amnon Shiloh
2012-11-23 17:42                     ` vdso && cr (Was: arch_check_bp_in_kernelspace: fix the range check) Oleg Nesterov
2012-11-23  9:14                   ` arch_check_bp_in_kernelspace: fix the range check Amnon Shiloh
2012-11-23 16:33                     ` Oleg Nesterov
2012-11-23 17:05                       ` Oleg Nesterov
2012-11-24 14:14                         ` Amnon Shiloh
2012-11-24 13:45                       ` Amnon Shiloh
2012-11-25 22:55                         ` Oleg Nesterov
2012-11-25 23:48                           ` Amnon Shiloh
2012-12-02 19:30                             ` PTRACE_SYSCALL && vsyscall (Was: arch_check_bp_in_kernelspace: fix the range check) Oleg Nesterov
2012-12-02 23:54                               ` u3557
2012-12-04 17:59                                 ` Oleg Nesterov
2012-12-04 22:44                                   ` u3557
2013-01-08 17:08                                   ` Pedro Alves
2013-01-09 17:52                                     ` Oleg Nesterov
2013-01-10  6:54                                       ` u3557
2013-01-12 18:12                                         ` Oleg Nesterov
2013-01-14  2:31                                           ` u3557
2013-01-14 16:01                                             ` Oleg Nesterov
2013-02-18  1:39                                               ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-18  5:44                                                 ` prctl(PR_SET_MM) Randy Dunlap
2013-02-18 15:21                                                 ` prctl(PR_SET_MM) Steven Rostedt
2013-02-18 16:33                                                   ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-18 19:49                                                     ` prctl(PR_SET_MM) Steven Rostedt
2013-02-19  6:25                                                       ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-20  8:39                                                         ` prctl(PR_SET_MM) Cyrill Gorcunov
2013-02-20  9:38                                                           ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-20 10:51                                                             ` prctl(PR_SET_MM) Cyrill Gorcunov
2013-02-20 11:16                                                               ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-21  7:46                                                               ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-21  8:00                                                                 ` prctl(PR_SET_MM) Cyrill Gorcunov
2013-02-21  8:03                                                                   ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-21  8:09                                                                     ` prctl(PR_SET_MM) Cyrill Gorcunov
2013-02-21 22:18                                                                   ` prctl(PR_SET_MM) Andrew Morton
2013-02-21 22:42                                                                     ` prctl(PR_SET_MM) Cyrill Gorcunov
2013-02-22  1:18                                                                     ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-22 14:23                                                         ` prctl(PR_SET_MM) Denys Vlasenko
2012-12-05  9:29                               ` PTRACE_SYSCALL && vsyscall (Was: arch_check_bp_in_kernelspace: fix the range check) Jan Kratochvil
2012-12-05 13:14                                 ` u3557
2012-11-26  9:44                   ` vdso && cr " Cyrill Gorcunov
2012-11-26 12:27                     ` Andrey Wagin
2012-11-26 12:55                       ` Amnon Shiloh
2012-11-26 14:18                         ` Cyrill Gorcunov
2012-11-26 14:26                           ` vdso && cr (Was: arch_check_bp_in_kernelspace: fix the range Amnon Shiloh
2012-11-26 14:41                             ` vdso && cr Cyrill Gorcunov

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