Go to file
Alexei Starovoitov bf956be520 umh: fix race condition
kasan reported use-after-free:
BUG: KASAN: use-after-free in call_usermodehelper_exec_work+0x2d3/0x310 kernel/umh.c:195
Write of size 4 at addr ffff8801d9202370 by task kworker/u4:2/50
Workqueue: events_unbound call_usermodehelper_exec_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_store4_noabort+0x17/0x20 mm/kasan/report.c:437
 call_usermodehelper_exec_work+0x2d3/0x310 kernel/umh.c:195
 process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145
 worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279
 kthread+0x345/0x410 kernel/kthread.c:240
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412

The reason is that 'sub_info' cannot be accessed out of parent task
context, since it will be freed by the child.
Instead remember the pid in the child task.

Fixes: 449325b52b ("umh: introduce fork_usermode_blob() helper")
Reported-by: syzbot+2c73319c406f1987d156@syzkaller.appspotmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-07 16:56:28 -04:00
Documentation media updates for v4.18-rc1 2018-06-07 12:34:37 -07:00
LICENSES LICENSES: Add Linux-OpenIB license text 2018-04-27 16:41:53 -06:00
arch net: in virtio_net_hdr only add VLAN_HLEN to csum_start if payload holds vlan 2018-06-07 16:15:38 -04:00
block Changes for 4.18: 2018-06-05 13:24:20 -07:00
certs certs/blacklist_nohashes.c: fix const confusion in certs blacklist 2018-02-21 15:35:43 -08:00
crypto - Introduce arithmetic overflow test helper functions (Rasmus) 2018-06-06 17:27:14 -07:00
drivers net: mscc: ocelot: Fix uninitialized error in ocelot_netdevice_event() 2018-06-07 16:54:39 -04:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs powerpc updates for 4.18 2018-06-07 10:23:33 -07:00
include net: in virtio_net_hdr only add VLAN_HLEN to csum_start if payload holds vlan 2018-06-07 16:15:38 -04:00
init Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
ipc Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 21:02:18 -07:00
kernel umh: fix race condition 2018-06-07 16:56:28 -04:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
mm Changes for 4.18: 2018-06-05 13:24:20 -07:00
net ip_tunnel: Fix name string concatenate in __ip_tunnel_create() 2018-06-07 16:27:16 -04:00
samples samples/bpf: xdpsock: use skb Tx path for XDP_SKB 2018-06-05 15:48:57 +02:00
scripts powerpc updates for 4.18 2018-06-07 10:23:33 -07:00
security Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
sound media updates for v4.18-rc1 2018-06-07 12:34:37 -07:00
tools powerpc updates for 4.18 2018-06-07 10:23:33 -07:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-06-04 15:23:48 -07:00
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap Merge branch 'asoc-4.17' into asoc-4.18 for compress dependencies 2018-04-26 12:24:28 +01:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: add basic helper macros to scripts/Kconfig.include 2018-05-29 03:31:19 +09:00
MAINTAINERS media updates for v4.18-rc1 2018-06-07 12:34:37 -07:00
Makefile Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

README

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.
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.