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ubuntucveUbuntu.comUB:CVE-2022-48906
HistoryAug 22, 2024 - 12:00 a.m.

CVE-2022-48906

2024-08-2200:00:00
ubuntu.com
ubuntu.com
2
linux kernel
cve-2022-48906
mptcp
data_fin
timeout
vulnerability
resolution
ubsan
shift-out-of-bounds
retransmits

AI Score

6.9

Confidence

Low

EPSS

0

Percentile

5.1%

In the Linux kernel, the following vulnerability has been resolved:
mptcp: Correctly set DATA_FIN timeout when number of retransmits is large
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.

AI Score

6.9

Confidence

Low

EPSS

0

Percentile

5.1%