{"id":"CVE-2025-38621","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nmd: make rdev_addable usable for rcu mode\n\nOur testcase trigger panic:\n\nBUG: kernel NULL pointer dereference, address: 00000000000000e0\n...\nOops: Oops: 0000 [#1] SMP NO…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nmd: make rdev_addable usable for rcu mode\n\nOur testcase trigger panic:\n\nBUG: kernel NULL pointer dereference, address: 00000000000000e0\n...\nOops: Oops: 0000 [#1] SMP NO…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-476"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 6.7, < 6.16.1"],"patched":["linux_kernel 6.16.1"],"published":"2025-08-22","updated":"2026-09-07","sourceUpdated":"2026-09-07T16:17:27.777","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-38621","references":[{"url":"https://git.kernel.org/stable/c/13017b427118f4311471ee47df74872372ca8482","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b5fbe940862339cdcc34dea7a057ad18d18fa137","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d713e105a6137d3f54f09d4d9e2273482057ca17","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.00159,"epssPercentile":0.04252,"ingestedAt":"2026-09-07T17:14:49.694Z","slug":"CVE-2025-38621","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nmd: make rdev_addable usable for rcu mode\n\nOur testcase trigger panic:\n\nBUG: kernel NULL pointer dereference, address: 00000000000000e0\n...\nOops: Oops: 0000 [#1] SMP NOPTI\nCPU: 2 UID: 0 PID: 85 Comm: kworker/2:1 Not tainted 6.16.0+ #94\nPREEMPT(none)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS\n1.16.1-2.fc37 04/01/2014\nWorkqueue: md_misc md_start_sync\nRIP: 0010:rdev_addable+0x4d/0xf0\n...\nCall Trace:\n <TASK>\n md_start_sync+0x329/0x480\n process_one_work+0x226/0x6d0\n worker_thread+0x19e/0x340\n kthread+0x10f/0x250\n ret_from_fork+0x14d/0x180\n ret_from_fork_asm+0x1a/0x30\n </TASK>\nModules linked in: raid10\nCR2: 00000000000000e0\n---[ end trace 0000000000000000 ]---\nRIP: 0010:rdev_addable+0x4d/0xf0\n\nmd_spares_need_change in md_start_sync will call rdev_addable which\nprotected by rcu_read_lock/rcu_read_unlock. This rcu context will help\nprotect rdev won't be released, but rdev->mddev will be set to NULL\nbefore we call synchronize_rcu in md_kick_rdev_from_array. Fix this by\nusing READ_ONCE and check does rdev->mddev still alive.\n\n## Affected\n\n- `linux_kernel >= 6.7, < 6.16.1`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.16.1`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}