CVE-2021-47124

Summary

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

io_uring: fix link timeout refs

WARNING: CPU: 0 PID: 10242 at lib/refcount.c:28 refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 RIP: 0010:refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 Call Trace: __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] io_put_req fs/io_uring.c:2140 [inline] io_queue_linked_timeout fs/io_uring.c:6300 [inline] __io_queue_sqe+0xbef/0xec0 fs/io_uring.c:6354 io_submit_sqe fs/io_uring.c:6534 [inline] io_submit_sqes+0x2bbd/0x7c50 fs/io_uring.c:6660 __do_sys_io_uring_enter fs/io_uring.c:9240 [inline] __se_sys_io_uring_enter+0x256/0x1d60 fs/io_uring.c:9182

io_link_timeout_fn() should put only one reference of the linked timeout request, however in case of racing with the master request's completion first io_req_complete() puts one and then io_put_req_deferred() is called.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux1c20e9040f49687ba2ccc2ffd4411351a6c2ebff < 0b2a990e5d2f76d020cb840c456e6ec5f0c27530affected
LinuxLinux1c20e9040f49687ba2ccc2ffd4411351a6c2ebff < 6f5d7a45f58d3abe3a936de1441b8d6318f978ffaffected
LinuxLinux9ae1f8dd372e0e4c020b345cf9e09f519265e981 < 876808dba2ff7509bdd7f230c4f374a0caf4f410affected
LinuxLinux9ae1f8dd372e0e4c020b345cf9e09f519265e981 < ff4a96ba5c8f9b266706280ff8021d2ef3f17e86affected
LinuxLinux9ae1f8dd372e0e4c020b345cf9e09f519265e981 < a298232ee6b9a1d5d732aa497ff8be0d45b5bd82affected
LinuxLinux567c81912cec641db75ac6cb64c63f8367c97d19affected
LinuxLinux5.10.26 < 5.10.43affected
LinuxLinux5.10.26 < 5.10.55affected
LinuxLinux5.11.6 < 5.12affected
LinuxLinux5.12affected
LinuxLinux0 < 5.12unaffected
LinuxLinux5.10.43 <= 5.10.*unaffected
LinuxLinux5.10.55 <= 5.10.*unaffected
LinuxLinux5.12.10 <= 5.12.*unaffected
LinuxLinux5.12.19 <= 5.12.*unaffected
LinuxLinux5.13 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

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

CVE Program Container

Additional References

References