CVE-2024-49976

Summary

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

tracing/timerlat: Drop interface_lock in stop_kthread()

stop_kthread() is the offline callback for "trace/osnoise:online", since commit 5bfbcd1ee57b ("tracing/timerlat: Add interface_lock around clearing of kthread in stop_kthread()"), the following ABBA deadlock scenario is introduced:

T1 | T2 [BP] | T3 [AP] osnoise_hotplug_workfn() | work_for_cpu_fn() | cpuhp_thread_fun() | _cpu_down() | osnoise_cpu_die() mutex_lock(&interface_lock) | | stop_kthread() | cpus_write_lock() | mutex_lock(&interface_lock) cpus_read_lock() | cpuhp_kick_ap() |

As the interface_lock here in just for protecting the "kthread" field of the osn_var, use xchg() instead to fix this issue. Also use for_each_online_cpu() back in stop_per_cpu_kthreads() as it can take cpu_read_lock() again.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxb4fdabffae14cca2c80d99bd81f3f27239ac7f5e < a4a05ceffe8fad68b45de38fe2311bda619e76e2affected
LinuxLinux4679272d5252720746fd9c5465352cbc5665f230 < 09cb44cc3d3df7ade2cebc939d6257a2fa8afc7aaffected
LinuxLinux5bfbcd1ee57b607fd29e4645c7f350dd385dd9ad < db8571a9a098086608c11a15856ff585789e67e8affected
LinuxLinux5bfbcd1ee57b607fd29e4645c7f350dd385dd9ad < b484a02c9cedf8703eff8f0756f94618004bd165affected
LinuxLinux6.6.51 < 6.6.55affected
LinuxLinux6.10.10 < 6.10.14affected
LinuxLinux6.11affected
LinuxLinux0 < 6.11unaffected
LinuxLinux6.6.55 <= 6.6.*unaffected
LinuxLinux6.10.14 <= 6.10.*unaffected
LinuxLinux6.11.3 <= 6.11.*unaffected
LinuxLinux6.12 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References