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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org,
	Jarkko Nikula <jarkko.nikula@linux.intel.com>,
	Logan Gunthorpe <logang@deltatee.com>,
	Bjorn Helgaas <bhelgaas@google.com>
Subject: [PATCH 4.19 25/30] PCI: Fix __initdata issue with "pci=disable_acs_redir" parameter
Date: Thu, 21 Feb 2019 15:36:07 +0100	[thread overview]
Message-ID: <20190221125252.000358199@linuxfoundation.org> (raw)
In-Reply-To: <20190221125250.543158526@linuxfoundation.org>

4.19-stable review patch.  If anyone has any objections, please let me know.

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

From: Logan Gunthorpe <logang@deltatee.com>

commit d2fd6e81912a665993b24dcdc1c1384a42a54f7e upstream.

The disable_acs_redir parameter stores a pointer to the string passed to
pci_setup().  However, the string passed to PCI setup is actually a
temporary copy allocated in static __initdata memory.  After init, once the
memory is freed, it is no longer valid to reference this pointer.

This bug was noticed in v5.0-rc1 after a change in commit c5eb1190074c
("PCI / PM: Allow runtime PM without callback functions") caused
pci_disable_acs_redir() to be called during shutdown which manifested
as an unable to handle kernel paging request at:

  RIP: 0010:pci_enable_acs+0x3f/0x1e0
  Call Trace:
     pci_restore_state.part.44+0x159/0x3c0
     pci_restore_standard_config+0x33/0x40
     pci_pm_runtime_resume+0x2b/0xd0
     ? pci_restore_standard_config+0x40/0x40
     __rpm_callback+0xbc/0x1b0
     rpm_callback+0x1f/0x70
     ? pci_restore_standard_config+0x40/0x40
      rpm_resume+0x4f9/0x710
     ? pci_conf1_read+0xb6/0xf0
     ? pci_conf1_write+0xb2/0xe0
     __pm_runtime_resume+0x47/0x70
     pci_device_shutdown+0x1e/0x60
     device_shutdown+0x14a/0x1f0
     kernel_restart+0xe/0x50
     __do_sys_reboot+0x1ee/0x210
     ? __fput+0x144/0x1d0
     do_writev+0x5e/0xf0
     ? do_writev+0x5e/0xf0
     do_syscall_64+0x48/0xf0
     entry_SYSCALL_64_after_hwframe+0x44/0xa9

It was also likely possible to trigger this bug when hotplugging PCI
devices.

To fix this, instead of storing a pointer, we use kstrdup() to copy the
disable_acs_redir_param to its own buffer which will never be freed.

Fixes: aaca43fda742 ("PCI: Add "pci=disable_acs_redir=" parameter for peer-to-peer support")
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/pci/pci.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -6113,7 +6113,8 @@ static int __init pci_setup(char *str)
 			} else if (!strncmp(str, "pcie_scan_all", 13)) {
 				pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
 			} else if (!strncmp(str, "disable_acs_redir=", 18)) {
-				disable_acs_redir_param = str + 18;
+				disable_acs_redir_param =
+					kstrdup(str + 18, GFP_KERNEL);
 			} else {
 				printk(KERN_ERR "PCI: Unknown option `%s'\n",
 						str);



  parent reply	other threads:[~2019-02-21 14:46 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-21 14:35 [PATCH 4.19 00/30] 4.19.25-stable review Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 01/30] af_packet: fix raw sockets over 6in4 tunnel Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 02/30] dsa: mv88e6xxx: Ensure all pending interrupts are handled prior to exit Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 03/30] mlxsw: __mlxsw_sp_port_headroom_set(): Fix a use of local variable Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 04/30] net: crypto set sk to NULL when af_alg_release Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 05/30] net: Fix for_each_netdev_feature on Big endian Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 06/30] net: fix IPv6 prefix route residue Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 07/30] net: ip6_gre: initialize erspan_ver just for erspan tunnels Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 08/30] net: ipv4: use a dedicated counter for icmp_v4 redirect packets Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 09/30] net: phy: xgmiitorgmii: Support generic PHY status read Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 10/30] net: stmmac: Fix a race in EEE enable callback Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 11/30] net: stmmac: handle endianness in dwmac4_get_timestamp Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 12/30] net: validate untrusted gso packets without csum offload Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 13/30] sky2: Increase D3 delay again Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 14/30] vhost: correctly check the return value of translate_desc() in log_used() Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 15/30] vsock: cope with memory allocation failure at socket creation time Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 16/30] vxlan: test dev->flags & IFF_UP before calling netif_rx() Greg Kroah-Hartman
2019-02-21 14:35 ` [PATCH 4.19 17/30] net: Add header for usage of fls64() Greg Kroah-Hartman
2019-02-21 14:36 ` [PATCH 4.19 18/30] tcp: clear icsk_backoff in tcp_write_queue_purge() Greg Kroah-Hartman
2019-02-21 14:36 ` [PATCH 4.19 19/30] tcp: tcp_v4_err() should be more careful Greg Kroah-Hartman
2019-02-21 14:36 ` [PATCH 4.19 20/30] net: Do not allocate page fragments that are not skb aligned Greg Kroah-Hartman
2019-02-21 14:36 ` [PATCH 4.19 21/30] hwmon: (lm80) Fix missing unlock on error in set_fan_div() Greg Kroah-Hartman
2019-02-21 14:36 ` [PATCH 4.19 22/30] scsi: target/core: Use kmem_cache_free() instead of kfree() Greg Kroah-Hartman
2019-02-21 14:36 ` [PATCH 4.19 23/30] x86_64: increase stack size for KASAN_EXTRA Greg Kroah-Hartman
2019-02-21 15:00   ` Andrey Ryabinin
2019-02-21 15:26     ` Greg Kroah-Hartman
2019-02-21 15:30       ` Andrey Ryabinin
2019-02-21 16:08         ` Greg Kroah-Hartman
2019-02-21 14:36 ` [PATCH 4.19 24/30] mmc: meson-gx: fix interrupt name Greg Kroah-Hartman
2019-02-21 14:36 ` Greg Kroah-Hartman [this message]
2019-02-21 14:36 ` [PATCH 4.19 26/30] sunrpc: fix 4 more call sites that were using stack memory with a scatterlist Greg Kroah-Hartman
2019-02-21 14:36 ` [PATCH 4.19 27/30] netfilter: nf_nat_snmp_basic: add missing length checks in ASN.1 cbs Greg Kroah-Hartman
2019-02-21 14:36 ` [PATCH 4.19 28/30] net/x25: do not hold the cpu too long in x25_new_lci() Greg Kroah-Hartman
2019-02-21 14:36 ` [PATCH 4.19 29/30] mISDN: fix a race in dev_expire_timer() Greg Kroah-Hartman
2019-02-21 14:36 ` [PATCH 4.19 30/30] ax25: fix possible use-after-free Greg Kroah-Hartman
2019-02-22  8:14 ` [PATCH 4.19 00/30] 4.19.25-stable review Jon Hunter
2019-02-22  8:24   ` Greg Kroah-Hartman
2019-02-22  9:04 ` Naresh Kamboju
2019-02-22 23:10 ` shuah
2019-02-22 23:31 ` Guenter Roeck

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