Description
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 > /sys/block/md0/md/array_state echo 10 > /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.
Metrics
No CVSS score has been published yet.
Affected software
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= d981ed8419303ed12351eea8541ad6cb76455fe3, < 903fb4851ee8d291372d285f616c398a9c4cbbec; >= d981ed8419303ed12351eea8541ad6cb76455fe3, < 9d37fe37dfa0833a8768740f0575e0ffd793cb4a; >= d981ed8419303ed12351eea8541ad6cb76455fe3, < 381a3ce1c0ffed647c9b913e142b099c7e9d5afc |
| Linux | Linux | 6.12 |
References
Timeline
- Published
- Dec 24, 2025
- Last modified
- Oct 21, 2026
- NVD status
- Deferred