mptcp: Correctly set DATA_FIN timeout when number of retransmits is large

Description

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.

Scores

EPSS (exploitation in 30 days)

0.21% · top 89% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.

Affected products

• Linux · Linux

  • affected 6477dd39e62c3a67cfa368ddc127410b4ae424c6 – < 0c3f34beb459753f9f80d0cc14c1b50ab615c631
  • affected 6477dd39e62c3a67cfa368ddc127410b4ae424c6 – < 03ae283bd71f761feae3f402668d698b393b0e79
  • affected 6477dd39e62c3a67cfa368ddc127410b4ae424c6 – < 877d11f0332cd2160e19e3313e262754c321fa36
  • affected 0af76111c2a6326e4bb56f64a6e453c6ec6dd2da
  • affected 5.12.4 – < 5.13

• Linux · Linux

  • affected 5.13
  • unaffected < 5.13
  • unaffected 5.15.27 – ≤ 5.15.*
  • unaffected 5.16.13 – ≤ 5.16.*
  • unaffected 5.17 – ≤ *

References (3)

• https://git.kernel.org/stable/c/0c3f34beb459753f9f80d0cc14c1b50ab615c631 (opens in a new tab)
• https://git.kernel.org/stable/c/03ae283bd71f761feae3f402668d698b393b0e79 (opens in a new tab)
• https://git.kernel.org/stable/c/877d11f0332cd2160e19e3313e262754c321fa36 (opens in a new tab)

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2022-48906](https://trackcve.app/badge/CVE-2022-48906.svg)](https://trackcve.app/cve/CVE-2022-48906)

Record last updated 23 May 2026, 15:21 UTC.