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Stefano Garzarella c070c1912a vhost-vdpa: fix an iotlb memory leak
Before commit 3d56987938 ("vhost-vdpa: introduce asid based IOTLB")
we called vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1) during
release to free all the resources allocated when processing user IOTLB
messages through vhost_vdpa_process_iotlb_update().
That commit changed the handling of IOTLB a bit, and we accidentally
removed some code called during the release.

We partially fixed this with commit 037d430556 ("vhost-vdpa: call
vhost_vdpa_cleanup during the release") but a potential memory leak is
still there as showed by kmemleak if the application does not send
VHOST_IOTLB_INVALIDATE or crashes:

  unreferenced object 0xffff888007fbaa30 (size 16):
    comm "blkio-bench", pid 914, jiffies 4294993521 (age 885.500s)
    hex dump (first 16 bytes):
      40 73 41 07 80 88 ff ff 00 00 00 00 00 00 00 00  @sA.............
    backtrace:
      [<0000000087736d2a>] kmem_cache_alloc_trace+0x142/0x1c0
      [<0000000060740f50>] vhost_vdpa_process_iotlb_msg+0x68c/0x901 [vhost_vdpa]
      [<0000000083e8e205>] vhost_chr_write_iter+0xc0/0x4a0 [vhost]
      [<000000008f2f414a>] vhost_vdpa_chr_write_iter+0x18/0x20 [vhost_vdpa]
      [<00000000de1cd4a0>] vfs_write+0x216/0x4b0
      [<00000000a2850200>] ksys_write+0x71/0xf0
      [<00000000de8e720b>] __x64_sys_write+0x19/0x20
      [<0000000018b12cbb>] do_syscall_64+0x3f/0x90
      [<00000000986ec465>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Let's fix this calling vhost_vdpa_iotlb_unmap() on the whole range in
vhost_vdpa_remove_as(). We move that call before vhost_dev_cleanup()
since we need a valid v->vdev.mm in vhost_vdpa_pa_unmap().
vhost_iotlb_reset() call can be removed, since vhost_vdpa_iotlb_unmap()
on the whole range removes all the entries.

The kmemleak log reported was observed with a vDPA device that has `use_va`
set to true (e.g. VDUSE). This patch has been tested with both types of
devices.

Fixes: 037d430556 ("vhost-vdpa: call vhost_vdpa_cleanup during the release")
Fixes: 3d56987938 ("vhost-vdpa: introduce asid based IOTLB")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20221109154213.146789-1-sgarzare@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
History 2022-12-28 05:28:10 -05:00
arch treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
block treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto This update includes the following changes: 2022-12-14 12:31:09 -08:00
Documentation kernel hardening fixes for v6.2-rc1 2022-12-23 12:00:24 -08:00
drivers vhost-vdpa: fix an iotlb memory leak 2022-12-28 05:28:10 -05:00
fs treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
include vdpa: merge functionally duplicated dev_features attributes 2022-12-28 05:09:46 -05:00
init Kbuild updates for v6.2 2022-12-19 12:33:32 -06:00
io_uring io_uring/net: fix cleanup after recycle 2022-12-19 08:28:28 -07:00
ipc Non-MM patches for 6.2-rc1. 2022-12-12 17:28:58 -08:00
kernel kernel hardening fixes for v6.2-rc1 2022-12-23 12:00:24 -08:00
lib test_maple_tree: add test for mas_spanning_rebalance() on insufficient data 2022-12-21 14:31:52 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm hugetlb: really allocate vma lock for all sharable vmas 2022-12-21 14:31:52 -08:00
net treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
rust rust: types: add Opaque type 2022-12-04 01:59:16 +01:00
samples Char/Misc driver changes for 6.2-rc1 2022-12-16 03:49:24 -08:00
scripts modernize use of grep in coccicheck 2022-12-23 13:56:41 -08:00
security kernel hardening fixes for v6.2-rc1 2022-12-23 12:00:24 -08:00
sound treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
tools tools: Delete the unneeded semicolon after curly braces 2022-12-28 05:28:10 -05:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt ARM64: 2022-12-15 11:12:21 -08:00
.clang-format iommufd for 6.2 2022-12-14 09:15:43 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: Cleanup DT Overlay intermediate files as appropriate 2022-11-18 14:45:30 -06:00
.mailmap Non-MM patches for 6.2-rc1. 2022-12-12 17:28:58 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: zram: zsmalloc: Add an additional co-maintainer 2022-12-15 16:37:49 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS io_uring-6.2-2022-12-19 2022-12-21 16:28:25 -08:00
Makefile Linux 6.2-rc1 2022-12-25 13:41:39 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.