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Leon Romanovsky 5c2e1c4f92 RDMA/uverbs: Fix bad unlock balance in ib_uverbs_close_xrcd
There is no matching lock for this mutex. Git history suggests this is
just a missed remnant from an earlier version of the function before
this locking was moved into uverbs_free_xrcd.

Originally this lock was protecting the xrcd_table_delete()

=====================================
WARNING: bad unlock balance detected!
4.15.0+ #87 Not tainted
-------------------------------------
syzkaller223405/269 is trying to release lock (&uverbs_dev->xrcd_tree_mutex) at:
[<00000000b8703372>] ib_uverbs_close_xrcd+0x195/0x1f0
but there are no more locks to release!

other info that might help us debug this:
1 lock held by syzkaller223405/269:
 #0:  (&uverbs_dev->disassociate_srcu){....}, at: [<000000005af3b960>] ib_uverbs_write+0x265/0xef0

stack backtrace:
CPU: 0 PID: 269 Comm: syzkaller223405 Not tainted 4.15.0+ #87
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
Call Trace:
 dump_stack+0xde/0x164
 ? dma_virt_map_sg+0x22c/0x22c
 ? ib_uverbs_write+0x265/0xef0
 ? console_unlock+0x502/0xbd0
 ? ib_uverbs_close_xrcd+0x195/0x1f0
 print_unlock_imbalance_bug+0x131/0x160
 lock_release+0x59d/0x1100
 ? ib_uverbs_close_xrcd+0x195/0x1f0
 ? lock_acquire+0x440/0x440
 ? lock_acquire+0x440/0x440
 __mutex_unlock_slowpath+0x88/0x670
 ? wait_for_completion+0x4c0/0x4c0
 ? rdma_lookup_get_uobject+0x145/0x2f0
 ib_uverbs_close_xrcd+0x195/0x1f0
 ? ib_uverbs_open_xrcd+0xdd0/0xdd0
 ib_uverbs_write+0x7f9/0xef0
 ? cyc2ns_read_end+0x10/0x10
 ? ib_uverbs_open_xrcd+0xdd0/0xdd0
 ? uverbs_devnode+0x110/0x110
 ? cyc2ns_read_end+0x10/0x10
 ? cyc2ns_read_end+0x10/0x10
 ? sched_clock_cpu+0x18/0x200
 __vfs_write+0x10d/0x700
 ? uverbs_devnode+0x110/0x110
 ? kernel_read+0x170/0x170
 ? __fget+0x358/0x5d0
 ? security_file_permission+0x93/0x260
 vfs_write+0x1b0/0x550
 SyS_write+0xc7/0x1a0
 ? SyS_read+0x1a0/0x1a0
 ? trace_hardirqs_on_thunk+0x1a/0x1c
 entry_SYSCALL_64_fastpath+0x1e/0x8b
RIP: 0033:0x4335c9

Cc: syzkaller <syzkaller@googlegroups.com>
Cc: <stable@vger.kernel.org> # 4.11
Fixes: fd3c7904db ("IB/core: Change idr objects to use the new schema")
Reported-by: Noa Osherovich <noaos@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-02-15 15:31:27 -07:00
Documentation KVM changes for 4.16 2018-02-10 13:16:35 -08:00
LICENSES LICENSES: Add MPL-1.1 license 2018-01-06 10:59:44 -07:00
arch unify {de,}mangle_poll(), get rid of kernel-side POLL... 2018-02-11 14:37:22 -08:00
block vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
drivers RDMA/uverbs: Fix bad unlock balance in ib_uverbs_close_xrcd 2018-02-15 15:31:27 -07:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
include IB/uverbs: Use __aligned_u64 for uapi headers 2018-02-15 14:59:45 -07:00
init membarrier: Provide core serializing command, *_SYNC_CORE 2018-02-05 21:35:03 +01:00
ipc vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
kernel vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
lib Kbuild updates for v4.16 (2nd) 2018-02-09 19:32:41 -08:00
mm vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
net vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
samples sample/bpf: fix erspan metadata 2018-02-06 11:32:49 -05:00
scripts Kbuild updates for v4.16 (2nd) 2018-02-09 19:32:41 -08:00
security vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
sound vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-02-09 15:34:18 -08:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore scripts/package: snap-pkg target 2017-12-13 00:00:18 +09:00
.mailmap mailmap: update Mark Yao's email address 2018-01-04 16:45:09 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS KVM changes for 4.16 2018-02-10 13:16:35 -08:00
Makefile Linux 4.16-rc1 2018-02-11 15:04:29 -08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README

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

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

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.