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CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-97925

tick/broadcast: Plug clockevents replacement race

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Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: tick/broadcast: Plug clockevents replacement race 朱恺乾 reported and decoded the following race condition when a broadcast device is replaced: CPUA CPUB __tick_broadcast_oneshot_control() bc = tick_broadcast_device.evtdev; tick_install_broadcast_device(dev) clockevents_exchange_device(cur, dev) shutdown(cur); detach(cur); cur->handler = noop; tick_broadcast_device.evtdev = dev; tick_broadcast_set_event(bc, next_event); <- FAIL: arms a detached device. If the original broadcast device has a restricted interrupt affinity mask and the last CPU in that mask goes offline then the BUG() in tick_cleanup_dead_cpu() triggers because the clockevent device is not in detached state. The reason for this is that tick_install_broadcast_device() is not serialized vs. tick broadcast operations. The obvious cure is to serialize tick_install_broadcast_device() with tick_broadcast_lock against a concurrent tick broadcast operation. That requires to split clockevents_exchange_device() into two parts, one which does the exchange, shutdown and detach operation and the other which drops the module reference count. This is required because the module reference cannot be dropped while holding tick_broadcast_lock. Let clockevents_exchange_device() do both operations as before, but let the broadcast device code take the two step approach and do the device exchange under tick_broadcast_lock and drop the module reference count after releasing it.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98 to < 9fa1fb4a876e10cc17182ce339625ec4d4b75f20affected
  • f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98 to < bc988724973b7f50d5dd05637f1e9ef4f009afd5affected
  • f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98 to < 338d6859cd1580617807290f6d7e92b1662d4695affected
  • f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98 to < 757aa9f548c18b96da1d56d11f65be8188a16d59affected
  • f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98 to < 3da55616db2b6b7d9caa3b7ff1e8983224e0ed52affected
  • f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98 to < 3525b94b2f258e0b99d1ee5a82a80b51bc1cc818affected
  • f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98 to < 292b7a8ed84032cfdfc9076a690360f7d3f640d4affected
  • f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98 to < 113a9796effe3376d2ec5aabcca1fef4fef4cd62affected

Linux Linux

Default version status: affected

  • 2.6.21affected
  • 0 to < 2.6.21unaffected
  • 5.10.273 to ≤ 5.10.*unaffected
  • 5.15.224 to ≤ 5.15.*unaffected
  • 6.1.189 to ≤ 6.1.*unaffected
  • 6.6.158 to ≤ 6.6.*unaffected
  • 6.12.111 to ≤ 6.12.*unaffected
  • 6.18.53 to ≤ 6.18.*unaffected
  • 7.2.7 to ≤ 7.2.*unaffected
  • 7.3 to ≤ *unaffected

References