CVE-2025-71194btrfs: fix deadlock in wait_current_trans() due to ignored transaction type
- —Not scoredno CVSS score yet
- 0.18%Exploitation in 30 daysEPSS · top 93% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix deadlock in wait_current_trans() due to ignored transaction type When wait_current_trans() is called during start_transaction(), it currently waits for a blocked transaction without considering whether the given transaction type actually needs to wait for that particular transaction state. The btrfs_blocked_trans_types[] array already defines which transaction types should wait for which transaction states, but this check was missing in wait_current_trans(). This can lead to a deadlock scenario involving two transactions and pending ordered extents: 1. Transaction A is in TRANS_STATE_COMMIT_DOING state 2. A worker processing an ordered extent calls start_transaction() with TRANS_JOIN 3. join_transaction() returns -EBUSY because Transaction A is in TRANS_STATE_COMMIT_DOING 4. Transaction A moves to TRANS_STATE_UNBLOCKED and completes 5. A new Transaction B is created (TRANS_STATE_RUNNING) 6. The ordered extent from step 2 is added to Transaction B's pending ordered extents 7. Transaction B immediately starts commit by another task and enters TRANS_STATE_COMMIT_START 8. The worker finally reaches wait_current_trans(), sees Transaction B in TRANS_STATE_COMMIT_START (a blocked state), and waits unconditionally 9. However, TRANS_JOIN should NOT wait for TRANS_STATE_COMMIT_START according to btrfs_blocked_trans_types[] 10. Transaction B is waiting for pending ordered extents to complete 11. Deadlock: Transaction B waits for ordered extent, ordered extent waits for Transaction B This can be illustrated by the following call stacks: CPU0 CPU1 btrfs_finish_ordered_io() start_transaction(TRANS_JOIN) join_transaction() # -EBUSY (Transaction A is # TRANS_STATE_COMMIT_DOING) # Transaction A completes # Transaction B created # ordered extent added to # Transaction B's pending list btrfs_commit_transaction() # Transaction B enters # TRANS_STATE_COMMIT_START # waiting for pending ordered # extents wait_current_trans() # waits for Transaction B # (should not wait!) Task bstore_kv_sync in btrfs_commit_transaction waiting for ordered extents: __schedule+0x2e7/0x8a0 schedule+0x64/0xe0 btrfs_commit_transaction+0xbf7/0xda0 [btrfs] btrfs_sync_file+0x342/0x4d0 [btrfs] __x64_sys_fdatasync+0x4b/0x80 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Task kworker in wait_current_trans waiting for transaction commit: Workqueue: btrfs-syno_nocow btrfs_work_helper [btrfs] __schedule+0x2e7/0x8a0 schedule+0x64/0xe0 wait_current_trans+0xb0/0x110 [btrfs] start_transaction+0x346/0x5b0 [btrfs] btrfs_finish_ordered_io.isra.0+0x49b/0x9c0 [btrfs] btrfs_work_helper+0xe8/0x350 [btrfs] process_one_work+0x1d3/0x3c0 worker_thread+0x4d/0x3e0 kthread+0x12d/0x150 ret_from_fork+0x1f/0x30 Fix this by passing the transaction type to wait_current_trans() and checking btrfs_blocked_trans_types[cur_trans->state] against the given type before deciding to wait. This ensures that transaction types which are allowed to join during certain blocked states will not unnecessarily wait and cause deadlocks.
Timeline
ID reserved
By Linux
- 4 days later
· 4 days later
Published
- 9 months later
· 9 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Deferred.
- EPSS (exploitation in 30 days)
- 0.18% · top 93% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 4a9d8bdee368de78ace8b36da4eb2186afea162d – < e563f59395981fcd69d130761290929806e728d6
- affected 4a9d8bdee368de78ace8b36da4eb2186afea162d – < dc84036c173cff6a432d9ab926298850b1d2a659
- affected 4a9d8bdee368de78ace8b36da4eb2186afea162d – < d7b04b40ac8e6d814e35202a0e1568809b818295
- affected 4a9d8bdee368de78ace8b36da4eb2186afea162d – < 99da896614d17e8a84aeb2b2d464ac046cc8633d
- affected 4a9d8bdee368de78ace8b36da4eb2186afea162d – < 8b0bb145d3bc264360f525c9717653be3522e528
- affected 4a9d8bdee368de78ace8b36da4eb2186afea162d – < 9ac63333d600732a56b35ee1fa46836da671eb50
- affected 4a9d8bdee368de78ace8b36da4eb2186afea162d – < 5037b342825df7094a4906d1e2a9674baab50cb2
- affected 3.11
- unaffected < 3.11
- unaffected 5.10.249 – ≤ 5.10.*
- unaffected 5.15.199 – ≤ 5.15.*
- unaffected 6.1.162 – ≤ 6.1.*
- unaffected 6.6.122 – ≤ 6.6.*
- unaffected 6.12.67 – ≤ 6.12.*
- unaffected 6.18.7 – ≤ 6.18.*
- unaffected 6.19 – ≤ *
References
References7
- https://git.kernel.org/stable/c/e563f59395981fcd69d130761290929806e728d6 (opens in a new tab)
- https://git.kernel.org/stable/c/dc84036c173cff6a432d9ab926298850b1d2a659 (opens in a new tab)
- https://git.kernel.org/stable/c/d7b04b40ac8e6d814e35202a0e1568809b818295 (opens in a new tab)
- https://git.kernel.org/stable/c/99da896614d17e8a84aeb2b2d464ac046cc8633d (opens in a new tab)
- https://git.kernel.org/stable/c/8b0bb145d3bc264360f525c9717653be3522e528 (opens in a new tab)
- https://git.kernel.org/stable/c/9ac63333d600732a56b35ee1fa46836da671eb50 (opens in a new tab)
- https://git.kernel.org/stable/c/5037b342825df7094a4906d1e2a9674baab50cb2 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-206804 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2025-71194)Record last updated .