Go to file
Nguyen Dinh Phi c2e390c4df tty: Fix data race between tiocsti() and flush_to_ldisc()
commit bb2853a6a421a052268eee00fd5d3f6b3504b2b1 upstream.

The ops->receive_buf() may be accessed concurrently from these two
functions.  If the driver flushes data to the line discipline
receive_buf() method while tiocsti() is waiting for the
ops->receive_buf() to finish its work, the data race will happen.

For example:
tty_ioctl			|tty_ldisc_receive_buf
 ->tioctsi			| ->tty_port_default_receive_buf
				|  ->tty_ldisc_receive_buf
   ->hci_uart_tty_receive	|   ->hci_uart_tty_receive
    ->h4_recv                   |    ->h4_recv

In this case, the h4 receive buffer will be overwritten by the
latecomer, and we will lost the data.

Hence, change tioctsi() function to use the exclusive lock interface
from tty_buffer to avoid the data race.

Reported-by: syzbot+97388eb9d31b997fe1d0@syzkaller.appspotmail.com
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Nguyen Dinh Phi <phind.uet@gmail.com>
Link: https://lore.kernel.org/r/20210823000641.2082292-1-phind.uet@gmail.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-05 19:13:40 +02:00
arch arm64: dts: marvell: armada-37xx: Extend PCIe MEM space 2024-07-05 19:12:04 +02:00
block bio: fix page leak bio_add_hw_page failure 2024-07-05 19:13:40 +02:00
certs certs: Trigger creation of RSA module signing key if it's not an RSA key 2024-07-05 19:10:21 +02:00
crypto init: add dsm gpl source 2024-07-05 18:00:04 +02:00
Documentation lkdtm: replace SCSI_DISPATCH_CMD with SCSI_QUEUE_RQ 2024-07-05 19:12:05 +02:00
drivers tty: Fix data race between tiocsti() and flush_to_ldisc() 2024-07-05 19:13:40 +02:00
fs io_uring: IORING_OP_WRITE needs hash_reg_file set 2024-07-05 19:13:40 +02:00
include time: Handle negative seconds correctly in timespec64_to_ns() 2024-07-05 19:13:39 +02:00
init init: add dsm gpl source 2024-07-05 18:00:04 +02:00
ipc ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry 2021-05-26 12:06:54 +02:00
kernel bpf: Fix possible out of bound write in narrow load handling 2024-07-05 19:12:23 +02:00
lib lib/mpi: use kcalloc in mpi_resize 2024-07-05 19:10:07 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm/page_alloc: speed up the iteration of max_order 2024-07-05 19:06:11 +02:00
net ipv4: fix endianness issue in inet_rtm_getroute_build_skb() 2024-07-05 19:13:33 +02:00
samples samples: pktgen: add missing IPv6 option to pktgen scripts 2024-07-05 19:11:56 +02:00
scripts scripts/tracing: fix the bug that can't parse raw_trace_func 2024-07-05 18:52:27 +02:00
security bpf: Add lockdown check for probe_write_user helper 2024-07-05 18:53:10 +02:00
sound ASoC: rt5682: Remove unused variable in rt5682_i2c_remove() 2024-07-05 19:13:39 +02:00
SynoBuildConf init: add dsm gpl source 2024-07-05 18:00:04 +02:00
synology init: add dsm gpl source 2024-07-05 18:00:04 +02:00
tools libbpf: Re-build libbpf.so when libbpf.map changes 2024-07-05 19:11:56 +02:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: Do not leak memory for duplicate debugfs directories 2024-07-05 18:52:31 +02:00
.clang-format init: add dsm gpl source 2024-07-05 18:00:04 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS init: add dsm gpl source 2024-07-05 18:00:04 +02:00
Makefile init: add dsm gpl source 2024-07-05 18:00:04 +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.