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Jason Gunthorpe 39c011a538 RDMA/uverbs: Fix a race with disassociate and exit_mmap()
If uverbs_user_mmap_disassociate() is called while the mmap is
concurrently doing exit_mmap then the ordering of the
rdma_user_mmap_entry_put() is not reliable.

The put must be done before uvers_user_mmap_disassociate() returns,
otherwise there can be a use after free on the ucontext, and a left over
entry in the xarray. If the put is not done here then it is done during
rdma_umap_close() later.

Add the missing put to the error exit path.

  WARNING: CPU: 7 PID: 7111 at drivers/infiniband/core/rdma_core.c:810 uverbs_destroy_ufile_hw+0x2a5/0x340 [ib_uverbs]
  Modules linked in: bonding ipip tunnel4 geneve ip6_udp_tunnel udp_tunnel ip6_gre ip6_tunnel tunnel6 ip_gre ip_tunnel gre mlx5_ib mlx5_core mlxfw pci_hyperv_intf act_ct nf_flow_table ptp pps_core rdma_ucm ib_uverbs ib_ipoib ib_umad 8021q garp mrp openvswitch nsh nf_conncount nfsv3 nfs_acl xt_MASQUERADE nf_conntrack_netlink nfnetlink iptable_nat xt_addrtype iptable_filter xt_conntrack br_netfilter bridge stp llc rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache overlay rpcrdma ib_isert iscsi_target_mod ib_iser kvm_intel ib_srpt iTCO_wdt target_core_mod iTCO_vendor_support kvm ib_srp nf_nat irqbypass crc32_pclmul crc32c_intel nf_conntrack rfkill nf_defrag_ipv6 virtio_net nf_defrag_ipv4 pcspkr ghash_clmulni_intel i2c_i801 net_failover failover i2c_core lpc_ich mfd_core rdma_cm ib_cm iw_cm button ib_core sunrpc sch_fq_codel ip_tables serio_raw [last unloaded: tunnel4]
  CPU: 7 PID: 7111 Comm: python3 Tainted: G        W         5.6.0-rc6-for-upstream-dbg-2020-03-21_06-41-26-18 #1
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
  RIP: 0010:uverbs_destroy_ufile_hw+0x2a5/0x340 [ib_uverbs]
  Code: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 74 49 8b 84 24 08 01 00 00 48 85 c0 0f 84 13 ff ff ff 48 89 ef ff d0 e9 09 ff ff ff <0f> 0b e9 77 ff ff ff e8 0f d8 fa e0 e9 c5 fd ff ff e8 05 d8 fa e0
  RSP: 0018:ffff88840e0779a0 EFLAGS: 00010286
  RAX: dffffc0000000000 RBX: ffff8882a7721c00 RCX: 0000000000000000
  RDX: 1ffff11054ee469f RSI: ffffffff8446d7e0 RDI: ffff8882a77234f8
  RBP: ffff8882a7723400 R08: ffffed1085c0112c R09: 0000000000000001
  R10: 0000000000000001 R11: ffffed1085c0112b R12: ffff888403c30000
  R13: 0000000000000002 R14: ffff8882a7721cb0 R15: ffff8882a7721cd0
  FS:  00007f2046089700(0000) GS:ffff88842de00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f7cfe9a6e20 CR3: 000000040b8ac006 CR4: 0000000000360ee0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   ib_uverbs_remove_one+0x273/0x480 [ib_uverbs]
   ? up_write+0x15c/0x4a0
   remove_client_context+0xa6/0xf0 [ib_core]
   disable_device+0x12d/0x200 [ib_core]
   ? remove_client_context+0xf0/0xf0 [ib_core]
   ? mnt_get_count+0x1d0/0x1d0
   __ib_unregister_device+0x79/0x150 [ib_core]
   ib_unregister_device+0x21/0x30 [ib_core]
   __mlx5_ib_remove+0x91/0x110 [mlx5_ib]
   ? __mlx5_ib_remove+0x110/0x110 [mlx5_ib]
   mlx5_remove_device+0x241/0x310 [mlx5_core]
   mlx5_unregister_device+0x4d/0x1e0 [mlx5_core]
   mlx5_unload_one+0xc0/0x260 [mlx5_core]
   remove_one+0x5c/0x160 [mlx5_core]
   pci_device_remove+0xef/0x2a0
   ? pcibios_free_irq+0x10/0x10
   device_release_driver_internal+0x1d8/0x470
   unbind_store+0x152/0x200
   ? sysfs_kf_write+0x3b/0x180
   ? sysfs_file_ops+0x160/0x160
   kernfs_fop_write+0x284/0x460
   ? __sb_start_write+0x243/0x3a0
   vfs_write+0x197/0x4a0
   ksys_write+0x156/0x1e0
   ? __x64_sys_read+0xb0/0xb0
   ? do_syscall_64+0x73/0x1330
   ? do_syscall_64+0x73/0x1330
   do_syscall_64+0xe7/0x1330
   ? down_write_nested+0x3e0/0x3e0
   ? syscall_return_slowpath+0x970/0x970
   ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe
   ? lockdep_hardirqs_off+0x1de/0x2d0
   ? trace_hardirqs_off_thunk+0x1a/0x1c
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x7f20a3ff0cdb
  Code: 53 48 89 d5 48 89 f3 48 83 ec 18 48 89 7c 24 08 e8 5a fd ff ff 48 89 ea 41 89 c0 48 89 de 48 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 90 fd ff ff 48
  RSP: 002b:00007f2046087040 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 00007f2038016df0 RCX: 00007f20a3ff0cdb
  RDX: 000000000000000d RSI: 00007f2038016df0 RDI: 0000000000000018
  RBP: 000000000000000d R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000100 R11: 0000000000000293 R12: 00007f2046e29630
  R13: 00007f20280035a0 R14: 0000000000000018 R15: 00007f2038016df0

Fixes: c043ff2cfb ("RDMA: Connect between the mmap entry and the umap_priv structure")
Link: https://lore.kernel.org/r/20200413132136.930388-1-leon@kernel.org
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-04-22 15:43:46 -03:00
Documentation Time(keeping) updates: 2020-04-12 10:13:14 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch A set of three patches to fix the fallout of the newly added split lock 2020-04-12 10:17:16 -07:00
block block-5.7-2020-04-10 2020-04-10 10:06:54 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto x86: update AS_* macros to binutils >=2.23, supporting ADX and AVX2 2020-04-09 00:12:48 +09:00
drivers RDMA/uverbs: Fix a race with disassociate and exit_mmap() 2020-04-22 15:43:46 -03:00
fs 10 smb fixes most RDMA (smbdirect) related, also add experimental support for swap over SMB3 mounts, and also adds fix which improves performance of signed connections 2020-04-12 09:41:01 -07:00
include Three small fixes/updates for the locking core code: 2020-04-12 09:47:10 -07:00
init Kbuild updates for v5.7 (2nd) 2020-04-11 09:46:12 -07:00
ipc ipc/util.c: sysvipc_find_ipc() should increase position index 2020-04-10 15:36:22 -07:00
kernel Time(keeping) updates: 2020-04-12 10:13:14 -07:00
lib Kbuild updates for v5.7 (2nd) 2020-04-11 09:46:12 -07:00
mm Merge branch 'akpm' (patches from Andrew) 2020-04-10 17:57:48 -07:00
net Kbuild updates for v5.7 (2nd) 2020-04-11 09:46:12 -07:00
samples samples/hw_breakpoint: drop use of kallsyms_lookup_name() 2020-04-07 10:43:44 -07:00
scripts kbuild: add dummy toolchains to enable all cc-option etc. in Kconfig 2020-04-09 00:13:45 +09:00
security Keyrings fixes 2020-04-04 12:24:47 -07:00
sound sound fixes for 5.7-rc1 2020-04-10 12:27:06 -07:00
tools Kbuild updates for v5.7 (2nd) 2020-04-11 09:46:12 -07:00
usr kbuild: fix comment about missing include guard detection 2020-04-11 12:09:48 +09:00
virt KVM: Pass kvm_init()'s opaque param to additional arch funcs 2020-03-31 10:48:03 -04:00
.clang-format clang-format: Update with the latest for_each macro list 2020-03-06 21:50:05 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
.mailmap mailmap: Add Sedat Dilek (replacement for expired email address) 2020-04-11 09:28:34 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Hand MIPS over to Thomas 2020-02-24 22:43:18 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: sort field names for all entries 2020-04-12 11:04:58 -07:00
Makefile Linux 5.7-rc1 2020-04-12 12:35:55 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.