[kernel/f19] CVE-2014-3534 s390: ptrace: insufficient sanitization with psw mask (rhbz 1114089 1122612)

[Josh Boyer]

commit 2f930a73fc75c6608b48cfca0ef80ffdc2b799c2
Author: Josh Boyer <jwboyer at fedoraproject.org>
Date:   Thu Jul 24 10:32:22 2014 -0400

    CVE-2014-3534 s390: ptrace: insufficient sanitization with psw mask (rhbz 1114089 1122612)

 kernel.spec                          |   10 ++++++
 s390-ptrace-fix-PSW-mask-check.patch |   59 ++++++++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+), 0 deletions(-)
---
diff --git a/kernel.spec b/kernel.spec
index 616df50..51f8d6f 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -761,6 +761,10 @@ Patch25111: 0002-ideapad-laptop-Change-Lenovo-Yoga-2-series-rfkill-ha.patch
 #CVE-2014-4943 rhbz 1119458 1120542
 Patch25115: net-l2tp-don-t-fall-back-on-UDP-get-set-sockopt.patch
 
+#CVE-2014-3534 rhbz 1114089 1122612
+Patch25117: s390-ptrace-fix-PSW-mask-check.patch
+
+
 # END OF PATCH DEFINITIONS
 
 %endif
@@ -1465,6 +1469,9 @@ ApplyPatch 0002-ideapad-laptop-Change-Lenovo-Yoga-2-series-rfkill-ha.patch
 #CVE-2014-4943 rhbz 1119458 1120542
 ApplyPatch net-l2tp-don-t-fall-back-on-UDP-get-set-sockopt.patch
 
+#CVE-2014-3534 rhbz 1114089 1122612
+ApplyPatch s390-ptrace-fix-PSW-mask-check.patch
+
 # END OF PATCH APPLICATIONS
 
 %endif
@@ -2277,6 +2284,9 @@ fi
 # and build.
 
 %changelog
+* Thu Jul 24 2014 Josh Boyer <jwboyer at fedoraproject.org>
+- CVE-2014-3534 s390: ptrace: insufficient sanitization with psw mask (rhbz 1114089 1122612)
+
 * Thu Jul 17 2014 Josh Boyer <jwboyer at fedoraproject.org> - 3.14.13-100
 - Linux v3.14.13
 - CVE-2014-4943 pppol2tp level handling (rhbz 1119458 1120542)
diff --git a/s390-ptrace-fix-PSW-mask-check.patch b/s390-ptrace-fix-PSW-mask-check.patch
new file mode 100644
index 0000000..9d54840
--- /dev/null
+++ b/s390-ptrace-fix-PSW-mask-check.patch
@@ -0,0 +1,59 @@
+Bugzilla: 1122612
+Upstream-status: 3.16 and CC'd to stable
+
+From dab6cf55f81a6e16b8147aed9a843e1691dcd318 Mon Sep 17 00:00:00 2001
+From: Martin Schwidefsky <schwidefsky at de.ibm.com>
+Date: Mon, 23 Jun 2014 15:29:40 +0200
+Subject: [PATCH] s390/ptrace: fix PSW mask check
+
+The PSW mask check of the PTRACE_POKEUSR_AREA command is incorrect.
+The PSW_MASK_USER define contains the PSW_MASK_ASC bits, the ptrace
+interface accepts all combinations for the address-space-control
+bits. To protect the kernel space the PSW mask check in ptrace needs
+to reject the address-space-control bit combination for home space.
+
+Fixes CVE-2014-3534
+
+Cc: stable at vger.kernel.org
+Signed-off-by: Martin Schwidefsky <schwidefsky at de.ibm.com>
+---
+ arch/s390/kernel/ptrace.c | 12 ++++++++++--
+ 1 file changed, 10 insertions(+), 2 deletions(-)
+
+diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
+index 2d716734b5b1..5dc7ad9e2fbf 100644
+--- a/arch/s390/kernel/ptrace.c
++++ b/arch/s390/kernel/ptrace.c
+@@ -334,9 +334,14 @@ static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
+ 			unsigned long mask = PSW_MASK_USER;
+ 
+ 			mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
+-			if ((data & ~mask) != PSW_USER_BITS)
++			if ((data ^ PSW_USER_BITS) & ~mask)
++				/* Invalid psw mask. */
++				return -EINVAL;
++			if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
++				/* Invalid address-space-control bits */
+ 				return -EINVAL;
+ 			if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
++				/* Invalid addressing mode bits */
+ 				return -EINVAL;
+ 		}
+ 		*(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
+@@ -672,9 +677,12 @@ static int __poke_user_compat(struct task_struct *child,
+ 
+ 			mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
+ 			/* Build a 64 bit psw mask from 31 bit mask. */
+-			if ((tmp & ~mask) != PSW32_USER_BITS)
++			if ((tmp ^ PSW32_USER_BITS) & ~mask)
+ 				/* Invalid psw mask. */
+ 				return -EINVAL;
++			if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
++				/* Invalid address-space-control bits */
++				return -EINVAL;
+ 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
+ 				(regs->psw.mask & PSW_MASK_BA) |
+ 				(__u64)(tmp & mask) << 32;
+-- 
+1.9.3
+