[PATCH 3.2 40/60] powerpc/rtas: Validate rtas.entry before calling enter_rtas()

From	Ben Hutchings <ben@decadent.org.uk>
Newsgroups	linux.kernel
Subject	[PATCH 3.2 40/60] powerpc/rtas: Validate rtas.entry before calling enter_rtas()
Date	2015-11-15 03:20 +0100
Message-ID	<quV57-3JS-9@gated-at.bofh.it> (permalink)
References	<quUVr-3GF-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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3.2.73-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>

commit 8832317f662c06f5c06e638f57bfe89a71c9b266 upstream.

Currently we do not validate rtas.entry before calling enter_rtas(). This
leads to a kernel oops when user space calls rtas system call on a powernv
platform (see below). This patch adds code to validate rtas.entry before
making enter_rtas() call.

  Oops: Exception in kernel mode, sig: 4 [#1]
  SMP NR_CPUS=1024 NUMA PowerNV
  task: c000000004294b80 ti: c0000007e1a78000 task.ti: c0000007e1a78000
  NIP: 0000000000000000 LR: 0000000000009c14 CTR: c000000000423140
  REGS: c0000007e1a7b920 TRAP: 0e40   Not tainted  (3.18.17-340.el7_1.pkvm3_1_0.2400.1.ppc64le)
  MSR: 1000000000081000 <HV,ME>  CR: 00000000  XER: 00000000
  CFAR: c000000000009c0c SOFTE: 0
  NIP [0000000000000000]           (null)
  LR [0000000000009c14] 0x9c14
  Call Trace:
  [c0000007e1a7bba0] [c00000000041a7f4] avc_has_perm_noaudit+0x54/0x110 (unreliable)
  [c0000007e1a7bd80] [c00000000002ddc0] ppc_rtas+0x150/0x2d0
  [c0000007e1a7be30] [c000000000009358] syscall_exit+0x0/0x98

Fixes: 55190f88789a ("powerpc: Add skeleton PowerNV platform")
Reported-by: NAGESWARA R. SASTRY <nasastry@in.ibm.com>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
[mpe: Reword change log, trim oops, and add stable + fixes]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 arch/powerpc/kernel/rtas.c | 3 +++
 1 file changed, 3 insertions(+)

--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -992,6 +992,9 @@ asmlinkage int ppc_rtas(struct rtas_args
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	if (!rtas.entry)
+		return -EINVAL;
+
 	if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
 		return -EFAULT;
 

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Thread

[PATCH 3.2 00/60] 3.2.73-rc1 review Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
  [PATCH 3.2 43/60] dm btree remove: fix a bug when rebalancing  nodes after removal Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
  [PATCH 3.2 27/60] 3w-9xxx: don't unmap bounce buffered commands Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
  [PATCH 3.2 12/60] genirq: Fix race in register_irq_proc() Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
  [PATCH 3.2 31/60] iommu/vt-d: fix range computation when making  room for large pages Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
  [PATCH 3.2 28/60] xen-blkfront: check for null drvdata in  blkback_changed (XenbusStateClosing) Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
  [PATCH 3.2 32/60] xhci: don't finish a TD if we get a short  transfer event mid TD Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
  [PATCH 3.2 46/60] md/raid1: don't clear bitmap bit when  bad-block-list write fails. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
  [PATCH 3.2 24/60] iwlwifi: dvm: fix D3 firmware PN programming Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
  [PATCH 3.2 04/60] regmap: debugfs: Don't bother actually printing  when calculating max length Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
  [PATCH 3.2 55/60] asix: Don't reset PHY on if_up for ASIX 88772 Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 08/60] UBI: Validate data_size Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 53/60] skbuff: Fix skb checksum partial check. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 38/60] IB/cm: Fix rb-tree duplicate free and  use-after-free Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 20/60] usb: Add device quirk for Logitech PTZ cameras Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 33/60] xhci: handle no ping response error properly Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 19/60] USB: Add reset-resume quirk for two Plantronics  usb headphones. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 44/60] dm btree: fix leak of bufio-backed block in  btree_split_beneath error path Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 40/60] powerpc/rtas: Validate rtas.entry before  calling enter_rtas() Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 34/60] xhci: Switch Intel Lynx Point LP ports to EHCI  on shutdown. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 07/60] x86/xen: Do not clip xen_e820_map to  xen_e820_map_entries when sanitizing map Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 03/60] regmap: debugfs: Ensure we don't underflow when  printing access masks Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 51/60] net: add length argument to  skb_copy_and_csum_datagram_iovec Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 05/60] ath9k: declare required extra tx headroom Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 39/60] drm/nouveau/gem: return only valid domain when  there's only one Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 06/60] m68k: Define asmlinkage_protect Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 26/60] sched/core: Fix TASK_DEAD race in  finish_task_switch() Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 45/60] md/raid1: ensure device failure recorded before  write request returns. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 15/60] md/raid0: update queue parameter in a safer  location. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 59/60] KEYS: Fix race between key destruction and  finding a keyring by name Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 23/60] ppp: don't override sk->sk_state in  pppoe_flush_dev() Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 49/60] mvsas: Fix NULL pointer dereference in  mvs_slot_task_free Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 58/60] KVM: x86: work around infinite loop in  microcode when #AC is delivered Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
  [PATCH 3.2 42/60] ppp: fix pppoe_dev deletion condition in  pppoe_release() Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
  [PATCH 3.2 10/60] MIPS: dma-default: Fix 32-bit fall back to GFP_DMA Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
  [PATCH 3.2 50/60] sched: declare pid_alive as inline Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
  [PATCH 3.2 17/60] clocksource: Fix abs() usage w/ 64bit values Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
  [PATCH 3.2 36/60] crypto: api - Only abort operations on fatal signal Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
  [PATCH 3.2 16/60] md/raid0: apply base queue limits *before*  disk_stack_limits Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
  [PATCH 3.2 47/60] md/raid10: ensure device failure recorded  before write request returns. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
  [PATCH 3.2 57/60] Failing to send a CLOSE if file is opened  WRONLY and server reboots on a 4.x mount Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
  [PATCH 3.2 14/60] [SMB3] Do not fall back to SMBWriteX in  set_file_size error cases Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
  Re: [PATCH 3.2 00/60] 3.2.73-rc1 review Guenter Roeck <linux@roeck-us.net> - 2015-11-15 14:50 +0100
    Re: [PATCH 3.2 00/60] 3.2.73-rc1 review Ben Hutchings <ben@decadent.org.uk> - 2015-11-16 12:20 +0100

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