kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-13 07:31:07 +00:00
Code Issues Releases Packages Activity
No description
710,210 commits 117 branches 5,827 tags 6.3 GiB
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Jack Morgenstein 7a748f0bb2 IB/umad: Fix use of unprotected device pointer 
commit f23a5350e4 upstream.

The ib_write_umad() is protected by taking the umad file mutex.
However, it accesses file->port->ib_dev -- which is protected only by the
port's mutex (field file_mutex).

The ib_umad_remove_one() calls ib_umad_kill_port() which sets
port->ib_dev to NULL under the port mutex (NOT the file mutex).
It then sets the mad agent to "dead" under the umad file mutex.

This is a race condition -- because there is a window where
port->ib_dev is NULL, while the agent is not "dead".

As a result, we saw stack traces like:

[16490.678059] BUG: unable to handle kernel NULL pointer dereference at 00000000000000b0
[16490.678246] IP: ib_umad_write+0x29c/0xa3a [ib_umad]
[16490.678333] PGD 0 P4D 0
[16490.678404] Oops: 0000 [#1] SMP PTI
[16490.678466] Modules linked in: rdma_ucm(OE) ib_ucm(OE) rdma_cm(OE) iw_cm(OE) ib_ipoib(OE) ib_cm(OE) ib_uverbs(OE) ib_umad(OE) mlx4_en(OE) ptp pps_core mlx4_ib(OE-) ib_core(OE) mlx4_core(OE) mlx_compat
(OE) memtrack(OE) devlink mst_pciconf(OE) mst_pci(OE) netconsole nfsv3 nfs_acl nfs lockd grace fscache cfg80211 rfkill esp6_offload esp6 esp4_offload esp4 sunrpc kvm_intel kvm ppdev parport_pc irqbypass
parport joydev i2c_piix4 virtio_balloon cirrus drm_kms_helper ttm drm e1000 serio_raw virtio_pci virtio_ring virtio ata_generic pata_acpi qemu_fw_cfg [last unloaded: mlxfw]
[16490.679202] CPU: 4 PID: 3115 Comm: sminfo Tainted: G           OE   4.14.13-300.fc27.x86_64 #1
[16490.679339] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu2 04/01/2014
[16490.679477] task: ffff9cf753890000 task.stack: ffffaf70c26b0000
[16490.679571] RIP: 0010:ib_umad_write+0x29c/0xa3a [ib_umad]
[16490.679664] RSP: 0018:ffffaf70c26b3d90 EFLAGS: 00010202
[16490.679747] RAX: 0000000000000010 RBX: ffff9cf75610fd80 RCX: 0000000000000000
[16490.679856] RDX: 0000000000000001 RSI: 00007ffdf2bfd714 RDI: ffff9cf6bb2a9c00

In the above trace, ib_umad_write is trying to dereference the NULL
file->port->ib_dev pointer.

Fix this by using the agent's device pointer (the device field
in struct ib_mad_agent) -- which IS protected by the umad file mutex.

Fixes: 44c58487d5 ("IB/core: Define 'ib' and 'roce' rdma_ah_attr types")
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2018-02-22 15:42:14 +01:00
arch mn10300/misalignment: Use SIGSEGV SEGV_MAPERR to report a failed user copy 2018-02-16 20:23:11 +01:00
block blk-mq: quiesce queue before freeing queue 2018-02-16 20:23:09 +01:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto crypto: hash - prevent using keyed hashes without setting key 2018-02-16 20:23:00 +01:00
Documentation arm64: cpu_errata: Add Kryo to Falkor 1003 errata 2018-02-16 20:22:48 +01:00
drivers IB/umad: Fix use of unprotected device pointer 2018-02-22 15:42:14 +01:00
firmware License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs devpts: fix error handling in devpts_mntget() 2018-02-16 20:23:11 +01:00
include scsi: core: Ensure that the SCSI error handler gets woken up 2018-02-16 20:23:11 +01:00
init bpf: introduce BPF_JIT_ALWAYS_ON config 2018-01-31 14:03:49 +01:00
ipc License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kernel tracing: Prevent PROFILE_ALL_BRANCHES when FORTIFY_SOURCE=y 2018-02-22 15:42:13 +01:00
lib lib/ubsan: add type mismatch handler for new GCC/Clang 2018-02-16 20:23:09 +01:00
mm Revert "defer call to mem_cgroup_sk_alloc()" 2018-02-13 10:19:48 +01:00
net dccp: CVE-2017-8824: use-after-free in DCCP code 2018-02-16 20:22:45 +01:00
samples samples/bpf: adjust rlimit RLIMIT_MEMLOCK for xdp1 2017-12-20 10:10:31 +01:00
scripts kasan: rework Kconfig settings 2018-02-16 20:23:04 +01:00
security ima/policy: fix parsing of fsuuid 2018-02-03 17:38:53 +01:00
sound ASoC: skl: Fix kernel warning due to zero NHTL entry 2018-02-16 20:23:04 +01:00
tools objtool: Fix switch-table detection 2018-02-16 20:23:09 +01:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt KVM: arm/arm64: Handle CPU_PM_ENTER_FAILED 2018-02-16 20:23:03 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: rpm-pkg: keep spec file until make mrproper 2018-02-13 10:19:46 +01:00
.mailmap .mailmap: Add Maciej W. Rozycki's Imagination e-mail address 2017-11-10 12:16:15 -08:00
COPYING [PATCH] update FSF address in COPYING 2005-09-10 10:06:29 -07:00
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Merge branch 'akpm' (patches from Andrew) 2017-11-09 18:26:51 -08:00
Makefile Linux 4.14.20 2018-02-16 20:23:12 +01:00
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.