Yishai Hadas f8ade8e242 IB/uverbs: Fix ioctl query port to consider device disassociation
Methods cannot peak into the ufile, the only way to get a ucontext and
hence a device is via the ib_uverbs_get_ucontext() call or inspecing a
locked uobject.

Otherwise during/after disassociation the pointers may be null or free'd.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
 PGD 800000005ece6067 P4D 800000005ece6067 PUD 5ece7067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 0 PID: 10631 Comm: ibv_ud_pingpong Tainted: GW  OE     4.20.0-rc6+ #3
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:ib_uverbs_handler_UVERBS_METHOD_QUERY_PORT+0x53/0x191 [ib_uverbs]
 Code: 80 00 00 00 31 c0 48 8b 47 40 48 8d 5c 24 38 48 8d 6c 24
               08 48 89 df 48 8b 40 08 4c 8b a0 18 03 00 00 31 c0 f3 48 ab 48 89
               ef <49> 83 7c 24 78 00 b1 06 f3 48 ab 0f 84 89 00 00 00 45 31  c9 31 d2
 RSP: 0018:ffffb54802ccfb10 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: ffffb54802ccfb48 RCX:0000000000000000
 RDX: fffffffffffffffa RSI: ffffb54802ccfcf8 RDI:ffffb54802ccfb18
 RBP: ffffb54802ccfb18 R08: ffffb54802ccfd18 R09:0000000000000000
 R10: 0000000000000000 R11: 00000000000000d0 R12:0000000000000000
 R13: ffffb54802ccfcb0 R14: ffffb54802ccfc48 R15:ffff9f736e0059a0
 FS:  00007f55a6bd7740(0000) GS:ffff9f737ba00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000078 CR3: 0000000064214000 CR4:00000000000006f0
 Call Trace:
  ib_uverbs_cmd_verbs.isra.5+0x94d/0xa60 [ib_uverbs]
  ? copy_port_attr_to_resp+0x120/0x120 [ib_uverbs]
  ? arch_tlb_finish_mmu+0x16/0xc0
  ? tlb_finish_mmu+0x1f/0x30
  ? unmap_region+0xd9/0x120
  ib_uverbs_ioctl+0xbc/0x120 [ib_uverbs]
  do_vfs_ioctl+0xa9/0x620
  ? __do_munmap+0x29f/0x3a0
  ksys_ioctl+0x60/0x90
  __x64_sys_ioctl+0x16/0x20
  do_syscall_64+0x5b/0x180
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7f55a62cb567

Fixes: 641d1207d2 ("IB/core: Move query port to ioctl")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-01-25 11:58:06 -07:00
2019-01-17 21:21:40 -07:00
2018-10-31 08:54:14 -07:00
2019-01-04 14:27:09 -07:00
2019-01-21 13:14:44 +13:00

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.
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