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Jason Gunthorpe 7c11910783 RDMA/ucma: Put a lock around every call to the rdma_cm layer
The rdma_cm must be used single threaded.

This appears to be a bug in the design, as it does have lots of locking
that seems like it should allow concurrency. However, when it is all said
and done every single place that uses the cma_exch() scheme is broken, and
all the unlocked reads from the ucma of the cm_id data are wrong too.

syzkaller has been finding endless bugs related to this.

Fixing this in any elegant way is some enormous amount of work. Take a
very big hammer and put a mutex around everything to do with the
ucma_context at the top of every syscall.

Fixes: 7521663857 ("RDMA/cma: Export rdma cm interface to userspace")
Link: https://lore.kernel.org/r/20200218210432.GA31966@ziepe.ca
Reported-by: syzbot+adb15cf8c2798e4e0db4@syzkaller.appspotmail.com
Reported-by: syzbot+e5579222b6a3edd96522@syzkaller.appspotmail.com
Reported-by: syzbot+4b628fcc748474003457@syzkaller.appspotmail.com
Reported-by: syzbot+29ee8f76017ce6cf03da@syzkaller.appspotmail.com
Reported-by: syzbot+6956235342b7317ec564@syzkaller.appspotmail.com
Reported-by: syzbot+b358909d8d01556b790b@syzkaller.appspotmail.com
Reported-by: syzbot+6b46b135602a3f3ac99e@syzkaller.appspotmail.com
Reported-by: syzbot+8458d13b13562abf6b77@syzkaller.appspotmail.com
Reported-by: syzbot+bd034f3fdc0402e942ed@syzkaller.appspotmail.com
Reported-by: syzbot+c92378b32760a4eef756@syzkaller.appspotmail.com
Reported-by: syzbot+68b44a1597636e0b342c@syzkaller.appspotmail.com
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-02-27 16:40:40 -04:00
arch Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
block block-5.6-2020-02-05 2020-02-06 06:15:23 +00:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto treewide: remove redundant IS_ERR() before error code check 2020-02-04 03:05:27 +00:00
Documentation Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
drivers RDMA/ucma: Put a lock around every call to the rdma_cm layer 2020-02-27 16:40:40 -04:00
fs Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
include RDMA: Replace zero-length array with flexible-array member 2020-02-20 13:33:51 -04:00
init Tracing updates: 2020-02-06 07:12:11 +00:00
ipc proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
kernel Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
lib Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-02-08 13:26:41 -08:00
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samples Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
scripts Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
security Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-02-08 13:26:41 -08:00
sound sound fixes for 5.6-rc1 2020-02-06 14:15:01 +00:00
tools A set of fixes and improvements for the perf subsystem: 2020-02-09 12:04:09 -08:00
usr Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
virt KVM: fix overflow of zero page refcount with ksm running 2020-02-05 15:27:46 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
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.gitignore modpost: dump missing namespaces into a single modules.nsdeps file 2019-11-11 20:10:01 +09:00
.mailmap A handful of small documentation fixes that wandered in. 2020-02-07 13:03:10 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS open: introduce openat2(2) syscall 2020-01-18 09:19:18 -05:00
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 fs: New zonefs file system 2020-02-09 15:51:46 -08:00
Makefile Linux 5.6-rc1 2020-02-09 16:08:48 -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.