CVE-2025-40281

Summary

In the Linux kernel, the following vulnerability has been resolved:

sctp: prevent possible shift-out-of-bounds in sctp_transport_update_rto

syzbot reported a possible shift-out-of-bounds [1]

Blamed commit added rto_alpha_max and rto_beta_max set to 1000.

It is unclear if some sctp users are setting very large rto_alpha and/or rto_beta.

In order to prevent user regression, perform the test at run time.

Also add READ_ONCE() annotations as sysctl values can change under us.

[1]

UBSAN: shift-out-of-bounds in net/sctp/transport.c:509:41 shift exponent 64 is too large for 32-bit type 'unsigned int' CPU: 0 UID: 0 PID: 16704 Comm: syz.2.2320 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:233 [inline] __ubsan_handle_shift_out_of_bounds+0x27f/0x420 lib/ubsan.c:494 sctp_transport_update_rto.cold+0x1c/0x34b net/sctp/transport.c:509 sctp_check_transmitted+0x11c4/0x1c30 net/sctp/outqueue.c:1502 sctp_outq_sack+0x4ef/0x1b20 net/sctp/outqueue.c:1338 sctp_cmd_process_sack net/sctp/sm_sideeffect.c:840 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1372 [inline]

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxb58537a1f5629bdc98a8b9dc2051ce0e952f6b4b < 0e0413e3315199b23ff4aec295e256034cd0a6e4affected
LinuxLinuxb58537a1f5629bdc98a8b9dc2051ce0e952f6b4b < 834e65be429c0fa4f9bb5945064bd57f18ed2187affected
LinuxLinuxb58537a1f5629bdc98a8b9dc2051ce0e952f6b4b < abb086b9a95d0ed3b757ee59964ba3c4e4b2fc1aaffected
LinuxLinuxb58537a1f5629bdc98a8b9dc2051ce0e952f6b4b < d0d858652834dcf531342c82a0428170aa7c2675affected
LinuxLinuxb58537a1f5629bdc98a8b9dc2051ce0e952f6b4b < ed71f801249d2350c77a73dca2c03918a15a62feaffected
LinuxLinuxb58537a1f5629bdc98a8b9dc2051ce0e952f6b4b < 1cfa4eac275cc4875755c1303d48a4ddfe507ca8affected
LinuxLinuxb58537a1f5629bdc98a8b9dc2051ce0e952f6b4b < aaba523dd7b6106526c24b1fd9b5fc35e5aaa88daffected
LinuxLinuxb58537a1f5629bdc98a8b9dc2051ce0e952f6b4b < 1534ff77757e44bcc4b98d0196bc5c0052fce5faaffected
LinuxLinux3.16affected
LinuxLinux0 < 3.16unaffected
LinuxLinux5.4.302 <= 5.4.*unaffected
LinuxLinux5.10.247 <= 5.10.*unaffected
LinuxLinux5.15.197 <= 5.15.*unaffected
LinuxLinux6.1.159 <= 6.1.*unaffected
LinuxLinux6.6.117 <= 6.6.*unaffected
LinuxLinux6.12.59 <= 6.12.*unaffected
LinuxLinux6.17.9 <= 6.17.*unaffected
LinuxLinux6.18 <= *unaffected

Weaknesses

ADP Enrichment

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References