forked from Minki/linux
mainlining shenanigans
877d11f033
Syzkaller with UBSAN uncovered a scenario where a large number of
DATA_FIN retransmits caused a shift-out-of-bounds in the DATA_FIN
timeout calculation:
================================================================================
UBSAN: shift-out-of-bounds in net/mptcp/protocol.c:470:29
shift exponent 32 is too large for 32-bit type 'unsigned int'
CPU: 1 PID: 13059 Comm: kworker/1:0 Not tainted 5.17.0-rc2-00630-g5fbf21c90c60 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Workqueue: events mptcp_worker
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
ubsan_epilogue+0xb/0x5a lib/ubsan.c:151
__ubsan_handle_shift_out_of_bounds.cold+0xb2/0x20e lib/ubsan.c:330
mptcp_set_datafin_timeout net/mptcp/protocol.c:470 [inline]
__mptcp_retrans.cold+0x72/0x77 net/mptcp/protocol.c:2445
mptcp_worker+0x58a/0xa70 net/mptcp/protocol.c:2528
process_one_work+0x9df/0x16d0 kernel/workqueue.c:2307
worker_thread+0x95/0xe10 kernel/workqueue.c:2454
kthread+0x2f4/0x3b0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
================================================================================
This change limits the maximum timeout by limiting the size of the
shift, which keeps all intermediate values in-bounds.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/259
Fixes:
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||
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arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
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. 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.