CVE-2025-68368

Wednesday, December 24, 2025

N/A

Summary

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

md: init bioset in mddev_init

IO operations may be needed before md_run(), such as updating metadata after writing sysfs. Without bioset, this triggers a NULL pointer dereference as below:

BUG: kernel NULL pointer dereference, address: 0000000000000020 Call Trace: md_update_sb+0x658/0xe00 new_level_store+0xc5/0x120 md_attr_store+0xc9/0x1e0 sysfs_kf_write+0x6f/0xa0 kernfs_fop_write_iter+0x141/0x2a0 vfs_write+0x1fc/0x5a0 ksys_write+0x79/0x180 __x64_sys_write+0x1d/0x30 x64_sys_call+0x2818/0x2880 do_syscall_64+0xa9/0x580 entry_SYSCALL_64_after_hwframe+0x4b/0x53

Reproducer

  mdadm -CR /dev/md0 -l1 -n2 /dev/sd[cd]
  echo inactive &gt; /sys/block/md0/md/array_state
  echo 10 &gt; /sys/block/md0/md/new_level

mddev_init() can only be called once per mddev, no need to test if bioset has been initialized anymore.

Affected Software

Vendor	Product	Version Range	Status
Linux	Linux	`d981ed8419303ed12351eea8541ad6cb76455fe3 < 9d37fe37dfa0833a8768740f0575e0ffd793cb4a`	affected
Linux	Linux	`d981ed8419303ed12351eea8541ad6cb76455fe3 < 381a3ce1c0ffed647c9b913e142b099c7e9d5afc`	affected
Linux	Linux	`6.12`	affected
Linux	Linux	`0 < 6.12`	unaffected
Linux	Linux	`6.18.2 <= 6.18.*`	unaffected
Linux	Linux	`6.19 <= *`	unaffected

Weaknesses

References

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