[kernel] r16293 - in dists/sid/linux-2.6/debian: . patches/bugfix/all patches/bugfix/x86 patches/series

Dann Frazier dannf at alioth.debian.org
Thu Sep 16 17:19:15 UTC 2010


Author: dannf
Date: Thu Sep 16 17:18:56 2010
New Revision: 16293

Log:
* compat: Make compat_alloc_user_space() incorporate the access_ok()
  (CVE-2010-3081)
* x86-64, compat (CVE-2010-3301):
  - Retruncate rax after ia32 syscall entry tracing
  - Test %rax for the syscall number, not %eax

Added:
   dists/sid/linux-2.6/debian/patches/bugfix/all/compat-make-compat_alloc_user_space-incorporate-the-access_ok.patch
   dists/sid/linux-2.6/debian/patches/bugfix/x86/compat-retruncate-rax-after-ia32-syscall-entry-tracing.patch
   dists/sid/linux-2.6/debian/patches/bugfix/x86/compat-test-rax-for-the-syscall-number-not-eax.patch
Modified:
   dists/sid/linux-2.6/debian/changelog
   dists/sid/linux-2.6/debian/patches/series/23

Modified: dists/sid/linux-2.6/debian/changelog
==============================================================================
--- dists/sid/linux-2.6/debian/changelog	Thu Sep 16 16:54:43 2010	(r16292)
+++ dists/sid/linux-2.6/debian/changelog	Thu Sep 16 17:18:56 2010	(r16293)
@@ -14,6 +14,13 @@
   * m68k: switch to generic siginfo layout.
   * m68k: NPTL support.
 
+  [ dann frazier ]
+  * compat: Make compat_alloc_user_space() incorporate the access_ok()
+    (CVE-2010-3081)
+  * x86-64, compat (CVE-2010-3301):
+    - Retruncate rax after ia32 syscall entry tracing
+    - Test %rax for the syscall number, not %eax
+
  -- Ben Hutchings <ben at decadent.org.uk>  Wed, 15 Sep 2010 11:21:18 +0100
 
 linux-2.6 (2.6.32-22) unstable; urgency=low

Added: dists/sid/linux-2.6/debian/patches/bugfix/all/compat-make-compat_alloc_user_space-incorporate-the-access_ok.patch
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ dists/sid/linux-2.6/debian/patches/bugfix/all/compat-make-compat_alloc_user_space-incorporate-the-access_ok.patch	Thu Sep 16 17:18:56 2010	(r16293)
@@ -0,0 +1,180 @@
+From c41d68a513c71e35a14f66d71782d27a79a81ea6 Mon Sep 17 00:00:00 2001
+From: H. Peter Anvin <hpa at linux.intel.com>
+Date: Tue, 7 Sep 2010 16:16:18 -0700
+Subject: compat: Make compat_alloc_user_space() incorporate the access_ok()
+
+From: H. Peter Anvin <hpa at linux.intel.com>
+
+commit c41d68a513c71e35a14f66d71782d27a79a81ea6 upstream.
+
+compat_alloc_user_space() expects the caller to independently call
+access_ok() to verify the returned area.  A missing call could
+introduce problems on some architectures.
+
+This patch incorporates the access_ok() check into
+compat_alloc_user_space() and also adds a sanity check on the length.
+The existing compat_alloc_user_space() implementations are renamed
+arch_compat_alloc_user_space() and are used as part of the
+implementation of the new global function.
+
+This patch assumes NULL will cause __get_user()/__put_user() to either
+fail or access userspace on all architectures.  This should be
+followed by checking the return value of compat_access_user_space()
+for NULL in the callers, at which time the access_ok() in the callers
+can also be removed.
+
+Reported-by: Ben Hawkes <hawkes at sota.gen.nz>
+Signed-off-by: H. Peter Anvin <hpa at linux.intel.com>
+Acked-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
+Acked-by: Chris Metcalf <cmetcalf at tilera.com>
+Acked-by: David S. Miller <davem at davemloft.net>
+Acked-by: Ingo Molnar <mingo at elte.hu>
+Acked-by: Thomas Gleixner <tglx at linutronix.de>
+Acked-by: Tony Luck <tony.luck at intel.com>
+Cc: Andrew Morton <akpm at linux-foundation.org>
+Cc: Arnd Bergmann <arnd at arndb.de>
+Cc: Fenghua Yu <fenghua.yu at intel.com>
+Cc: H. Peter Anvin <hpa at zytor.com>
+Cc: Heiko Carstens <heiko.carstens at de.ibm.com>
+Cc: Helge Deller <deller at gmx.de>
+Cc: James Bottomley <jejb at parisc-linux.org>
+Cc: Kyle McMartin <kyle at mcmartin.ca>
+Cc: Martin Schwidefsky <schwidefsky at de.ibm.com>
+Cc: Paul Mackerras <paulus at samba.org>
+Cc: Ralf Baechle <ralf at linux-mips.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh at suse.de>
+
+---
+ arch/ia64/include/asm/compat.h    |    2 +-
+ arch/mips/include/asm/compat.h    |    2 +-
+ arch/parisc/include/asm/compat.h  |    2 +-
+ arch/powerpc/include/asm/compat.h |    2 +-
+ arch/s390/include/asm/compat.h    |    2 +-
+ arch/sparc/include/asm/compat.h   |    2 +-
+ arch/x86/include/asm/compat.h     |    2 +-
+ include/linux/compat.h            |    2 ++
+ kernel/compat.c                   |   22 ++++++++++++++++++++++
+ 9 files changed, 31 insertions(+), 7 deletions(-)
+
+--- a/arch/ia64/include/asm/compat.h
++++ b/arch/ia64/include/asm/compat.h
+@@ -198,7 +198,7 @@ ptr_to_compat(void __user *uptr)
+ }
+ 
+ static __inline__ void __user *
+-compat_alloc_user_space (long len)
++arch_compat_alloc_user_space (long len)
+ {
+ 	struct pt_regs *regs = task_pt_regs(current);
+ 	return (void __user *) (((regs->r12 & 0xffffffff) & -16) - len);
+--- a/arch/mips/include/asm/compat.h
++++ b/arch/mips/include/asm/compat.h
+@@ -144,7 +144,7 @@ static inline compat_uptr_t ptr_to_compa
+ 	return (u32)(unsigned long)uptr;
+ }
+ 
+-static inline void __user *compat_alloc_user_space(long len)
++static inline void __user *arch_compat_alloc_user_space(long len)
+ {
+ 	struct pt_regs *regs = (struct pt_regs *)
+ 		((unsigned long) current_thread_info() + THREAD_SIZE - 32) - 1;
+--- a/arch/parisc/include/asm/compat.h
++++ b/arch/parisc/include/asm/compat.h
+@@ -146,7 +146,7 @@ static inline compat_uptr_t ptr_to_compa
+ 	return (u32)(unsigned long)uptr;
+ }
+ 
+-static __inline__ void __user *compat_alloc_user_space(long len)
++static __inline__ void __user *arch_compat_alloc_user_space(long len)
+ {
+ 	struct pt_regs *regs = &current->thread.regs;
+ 	return (void __user *)regs->gr[30];
+--- a/arch/powerpc/include/asm/compat.h
++++ b/arch/powerpc/include/asm/compat.h
+@@ -133,7 +133,7 @@ static inline compat_uptr_t ptr_to_compa
+ 	return (u32)(unsigned long)uptr;
+ }
+ 
+-static inline void __user *compat_alloc_user_space(long len)
++static inline void __user *arch_compat_alloc_user_space(long len)
+ {
+ 	struct pt_regs *regs = current->thread.regs;
+ 	unsigned long usp = regs->gpr[1];
+--- a/arch/s390/include/asm/compat.h
++++ b/arch/s390/include/asm/compat.h
+@@ -180,7 +180,7 @@ static inline int is_compat_task(void)
+ 
+ #endif
+ 
+-static inline void __user *compat_alloc_user_space(long len)
++static inline void __user *arch_compat_alloc_user_space(long len)
+ {
+ 	unsigned long stack;
+ 
+--- a/arch/sparc/include/asm/compat.h
++++ b/arch/sparc/include/asm/compat.h
+@@ -166,7 +166,7 @@ static inline compat_uptr_t ptr_to_compa
+ 	return (u32)(unsigned long)uptr;
+ }
+ 
+-static inline void __user *compat_alloc_user_space(long len)
++static inline void __user *arch_compat_alloc_user_space(long len)
+ {
+ 	struct pt_regs *regs = current_thread_info()->kregs;
+ 	unsigned long usp = regs->u_regs[UREG_I6];
+--- a/arch/x86/include/asm/compat.h
++++ b/arch/x86/include/asm/compat.h
+@@ -204,7 +204,7 @@ static inline compat_uptr_t ptr_to_compa
+ 	return (u32)(unsigned long)uptr;
+ }
+ 
+-static inline void __user *compat_alloc_user_space(long len)
++static inline void __user *arch_compat_alloc_user_space(long len)
+ {
+ 	struct pt_regs *regs = task_pt_regs(current);
+ 	return (void __user *)regs->sp - len;
+--- a/include/linux/compat.h
++++ b/include/linux/compat.h
+@@ -309,5 +309,7 @@ asmlinkage long compat_sys_newfstatat(un
+ asmlinkage long compat_sys_openat(unsigned int dfd, const char __user *filename,
+ 				  int flags, int mode);
+ 
++extern void __user *compat_alloc_user_space(unsigned long len);
++
+ #endif /* CONFIG_COMPAT */
+ #endif /* _LINUX_COMPAT_H */
+--- a/kernel/compat.c
++++ b/kernel/compat.c
+@@ -25,6 +25,7 @@
+ #include <linux/posix-timers.h>
+ #include <linux/times.h>
+ #include <linux/ptrace.h>
++#include <linux/module.h>
+ 
+ #include <asm/uaccess.h>
+ 
+@@ -1136,3 +1137,24 @@ compat_sys_sysinfo(struct compat_sysinfo
+ 
+ 	return 0;
+ }
++
++/*
++ * Allocate user-space memory for the duration of a single system call,
++ * in order to marshall parameters inside a compat thunk.
++ */
++void __user *compat_alloc_user_space(unsigned long len)
++{
++	void __user *ptr;
++
++	/* If len would occupy more than half of the entire compat space... */
++	if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
++		return NULL;
++
++	ptr = arch_compat_alloc_user_space(len);
++
++	if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))
++		return NULL;
++
++	return ptr;
++}
++EXPORT_SYMBOL_GPL(compat_alloc_user_space);

Added: dists/sid/linux-2.6/debian/patches/bugfix/x86/compat-retruncate-rax-after-ia32-syscall-entry-tracing.patch
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ dists/sid/linux-2.6/debian/patches/bugfix/x86/compat-retruncate-rax-after-ia32-syscall-entry-tracing.patch	Thu Sep 16 17:18:56 2010	(r16293)
@@ -0,0 +1,50 @@
+From eefdca043e8391dcd719711716492063030b55ac Mon Sep 17 00:00:00 2001
+From: Roland McGrath <roland at redhat.com>
+Date: Tue, 14 Sep 2010 12:22:58 -0700
+Subject: x86-64, compat: Retruncate rax after ia32 syscall entry tracing
+
+From: Roland McGrath <roland at redhat.com>
+
+commit eefdca043e8391dcd719711716492063030b55ac upstream.
+
+In commit d4d6715, we reopened an old hole for a 64-bit ptracer touching a
+32-bit tracee in system call entry.  A %rax value set via ptrace at the
+entry tracing stop gets used whole as a 32-bit syscall number, while we
+only check the low 32 bits for validity.
+
+Fix it by truncating %rax back to 32 bits after syscall_trace_enter,
+in addition to testing the full 64 bits as has already been added.
+
+Reported-by: Ben Hawkes <hawkes at sota.gen.nz>
+Signed-off-by: Roland McGrath <roland at redhat.com>
+Signed-off-by: H. Peter Anvin <hpa at linux.intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh at suse.de>
+
+---
+ arch/x86/ia32/ia32entry.S |    8 +++++++-
+ 1 file changed, 7 insertions(+), 1 deletion(-)
+
+--- a/arch/x86/ia32/ia32entry.S
++++ b/arch/x86/ia32/ia32entry.S
+@@ -50,7 +50,12 @@
+ 	/*
+ 	 * Reload arg registers from stack in case ptrace changed them.
+ 	 * We don't reload %eax because syscall_trace_enter() returned
+-	 * the value it wants us to use in the table lookup.
++	 * the %rax value we should see.  Instead, we just truncate that
++	 * value to 32 bits again as we did on entry from user mode.
++	 * If it's a new value set by user_regset during entry tracing,
++	 * this matches the normal truncation of the user-mode value.
++	 * If it's -1 to make us punt the syscall, then (u32)-1 is still
++	 * an appropriately invalid value.
+ 	 */
+ 	.macro LOAD_ARGS32 offset, _r9=0
+ 	.if \_r9
+@@ -60,6 +65,7 @@
+ 	movl \offset+48(%rsp),%edx
+ 	movl \offset+56(%rsp),%esi
+ 	movl \offset+64(%rsp),%edi
++	movl %eax,%eax			/* zero extension */
+ 	.endm
+ 	
+ 	.macro CFI_STARTPROC32 simple

Added: dists/sid/linux-2.6/debian/patches/bugfix/x86/compat-test-rax-for-the-syscall-number-not-eax.patch
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ dists/sid/linux-2.6/debian/patches/bugfix/x86/compat-test-rax-for-the-syscall-number-not-eax.patch	Thu Sep 16 17:18:56 2010	(r16293)
@@ -0,0 +1,97 @@
+From 36d001c70d8a0144ac1d038f6876c484849a74de Mon Sep 17 00:00:00 2001
+From: H. Peter Anvin <hpa at linux.intel.com>
+Date: Tue, 14 Sep 2010 12:42:41 -0700
+Subject: x86-64, compat: Test %rax for the syscall number, not %eax
+
+From: H. Peter Anvin <hpa at linux.intel.com>
+
+commit 36d001c70d8a0144ac1d038f6876c484849a74de upstream.
+
+On 64 bits, we always, by necessity, jump through the system call
+table via %rax.  For 32-bit system calls, in theory the system call
+number is stored in %eax, and the code was testing %eax for a valid
+system call number.  At one point we loaded the stored value back from
+the stack to enforce zero-extension, but that was removed in checkin
+d4d67150165df8bf1cc05e532f6efca96f907cab.  An actual 32-bit process
+will not be able to introduce a non-zero-extended number, but it can
+happen via ptrace.
+
+Instead of re-introducing the zero-extension, test what we are
+actually going to use, i.e. %rax.  This only adds a handful of REX
+prefixes to the code.
+
+Reported-by: Ben Hawkes <hawkes at sota.gen.nz>
+Signed-off-by: H. Peter Anvin <hpa at linux.intel.com>
+Cc: Roland McGrath <roland at redhat.com>
+Cc: Andrew Morton <akpm at linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh at suse.de>
+
+---
+ arch/x86/ia32/ia32entry.S |   14 +++++++-------
+ 1 file changed, 7 insertions(+), 7 deletions(-)
+
+--- a/arch/x86/ia32/ia32entry.S
++++ b/arch/x86/ia32/ia32entry.S
+@@ -153,7 +153,7 @@ ENTRY(ia32_sysenter_target)
+ 	testl  $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
+ 	CFI_REMEMBER_STATE
+ 	jnz  sysenter_tracesys
+-	cmpl	$(IA32_NR_syscalls-1),%eax
++	cmpq	$(IA32_NR_syscalls-1),%rax
+ 	ja	ia32_badsys
+ sysenter_do_call:
+ 	IA32_ARG_FIXUP
+@@ -195,7 +195,7 @@ sysexit_from_sys_call:
+ 	movl $AUDIT_ARCH_I386,%edi	/* 1st arg: audit arch */
+ 	call audit_syscall_entry
+ 	movl RAX-ARGOFFSET(%rsp),%eax	/* reload syscall number */
+-	cmpl $(IA32_NR_syscalls-1),%eax
++	cmpq $(IA32_NR_syscalls-1),%rax
+ 	ja ia32_badsys
+ 	movl %ebx,%edi			/* reload 1st syscall arg */
+ 	movl RCX-ARGOFFSET(%rsp),%esi	/* reload 2nd syscall arg */
+@@ -248,7 +248,7 @@ sysenter_tracesys:
+ 	call	syscall_trace_enter
+ 	LOAD_ARGS32 ARGOFFSET  /* reload args from stack in case ptrace changed it */
+ 	RESTORE_REST
+-	cmpl	$(IA32_NR_syscalls-1),%eax
++	cmpq	$(IA32_NR_syscalls-1),%rax
+ 	ja	int_ret_from_sys_call /* sysenter_tracesys has set RAX(%rsp) */
+ 	jmp	sysenter_do_call
+ 	CFI_ENDPROC
+@@ -314,7 +314,7 @@ ENTRY(ia32_cstar_target)
+ 	testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
+ 	CFI_REMEMBER_STATE
+ 	jnz   cstar_tracesys
+-	cmpl $IA32_NR_syscalls-1,%eax
++	cmpq $IA32_NR_syscalls-1,%rax
+ 	ja  ia32_badsys
+ cstar_do_call:
+ 	IA32_ARG_FIXUP 1
+@@ -367,7 +367,7 @@ cstar_tracesys:
+ 	LOAD_ARGS32 ARGOFFSET, 1  /* reload args from stack in case ptrace changed it */
+ 	RESTORE_REST
+ 	xchgl %ebp,%r9d
+-	cmpl $(IA32_NR_syscalls-1),%eax
++	cmpq $(IA32_NR_syscalls-1),%rax
+ 	ja int_ret_from_sys_call /* cstar_tracesys has set RAX(%rsp) */
+ 	jmp cstar_do_call
+ END(ia32_cstar_target)
+@@ -425,7 +425,7 @@ ENTRY(ia32_syscall)
+ 	orl   $TS_COMPAT,TI_status(%r10)
+ 	testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
+ 	jnz ia32_tracesys
+-	cmpl $(IA32_NR_syscalls-1),%eax
++	cmpq $(IA32_NR_syscalls-1),%rax
+ 	ja ia32_badsys
+ ia32_do_call:
+ 	IA32_ARG_FIXUP
+@@ -444,7 +444,7 @@ ia32_tracesys:
+ 	call syscall_trace_enter
+ 	LOAD_ARGS32 ARGOFFSET  /* reload args from stack in case ptrace changed it */
+ 	RESTORE_REST
+-	cmpl $(IA32_NR_syscalls-1),%eax
++	cmpq $(IA32_NR_syscalls-1),%rax
+ 	ja  int_ret_from_sys_call	/* ia32_tracesys has set RAX(%rsp) */
+ 	jmp ia32_do_call
+ END(ia32_syscall)

Modified: dists/sid/linux-2.6/debian/patches/series/23
==============================================================================
--- dists/sid/linux-2.6/debian/patches/series/23	Thu Sep 16 16:54:43 2010	(r16292)
+++ dists/sid/linux-2.6/debian/patches/series/23	Thu Sep 16 17:18:56 2010	(r16293)
@@ -8,3 +8,6 @@
 
 + bugfix/m68k/linux-2.6.git-5da3a65d2d1ba333d61999640ef241f150c69c6b.patch
 + bugfix/m68k/linux-2.6.git-9674cdc74d63f346870943ef966a034f8c71ee57.patch
++ bugfix/x86/compat-test-rax-for-the-syscall-number-not-eax.patch
++ bugfix/all/compat-make-compat_alloc_user_space-incorporate-the-access_ok.patch
++ bugfix/x86/compat-retruncate-rax-after-ia32-syscall-entry-tracing.patch



More information about the Kernel-svn-changes mailing list