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Jason Gunthorpe 51795bcf59 RDMA/ucma: Put a lock around every call to the rdma_cm layer
commit 7c11910783 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-13 10:48:12 +02:00
arch ARM: imx: only select ARM_ERRATA_814220 for ARMv7-A 2020-04-13 10:48:11 +02:00
block block, bfq: fix overwrite of bfq_group pointer in bfq_find_set_group() 2020-03-25 08:25:49 +01:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto crypto: rename sm3-256 to sm3 in hash_algo_name 2020-02-28 17:22:26 +01:00
Documentation dt-bindings: net: FMan erratum A050385 2020-04-01 11:01:52 +02:00
drivers RDMA/ucma: Put a lock around every call to the rdma_cm layer 2020-04-13 10:48:12 +02:00
fs ceph: canonicalize server path in place 2020-04-13 10:48:11 +02:00
include include/uapi/linux/swab.h: fix userspace breakage, use __BITS_PER_LONG for swap 2020-04-13 10:48:12 +02:00
init kbuild: remove header compile test 2020-03-05 16:43:47 +01:00
ipc Revert "ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()" 2020-02-28 17:22:20 +01:00
kernel padata: always acquire cpu_hotplug_lock before pinst->lock 2020-04-08 09:08:47 +02:00
lib uapi: rename ext2_swab() to swab() and share globally in swab.h 2020-04-13 10:48:07 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm slub: improve bit diffusion for freelist ptr obfuscation 2020-04-13 10:48:07 +02:00
net net_sched: fix a missing refcnt in tcindex_init() 2020-04-13 10:48:04 +02:00
samples samples/bpf: Set -fno-stack-protector when building BPF programs 2020-02-24 08:36:36 +01:00
scripts kconfig: introduce m32-flag and m64-flag 2020-04-08 09:08:37 +02:00
security efi: Only print errors about failing to get certs if EFI vars are found 2020-03-12 13:00:14 +01:00
sound ASoC: jz4740-i2s: Fix divider written at incorrect offset in register 2020-04-13 10:48:09 +02:00
tools tools/accounting/getdelays.c: fix netlink attribute length 2020-04-13 10:48:08 +02:00
usr initramfs: restore default compression behavior 2020-04-08 09:08:38 +02:00
virt KVM: Check for a bad hva before dropping into the ghc slow path 2020-03-05 16:43:48 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: Update drm/i915 bug filing URL 2020-02-28 17:22:19 +01:00
Makefile Linux 5.4.31 2020-04-08 09:08:47 +02:00
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.