Answer in brief
CVE-2025-22115 records a High severity (CVSS 7.8) vulnerability in btrfs: fix block group refcount race in btrfs_create_pending_block_groups(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.5:-:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.5:rc3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.5:rc4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.5:rc5:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.5:rc6:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.5:rc7:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | 6.5 | Not reported |
| Linux/Linuxgeneric | >=0657b20c5a76c938612f8409735a8830d257866e <ee56da95f8962b86fec4ef93f866e64c8d025a58 || >=0657b20c5a76c938612f8409735a8830d257866e <9d383a6fc59271aaaf07a33b23b2eac5b9268b7a || >=0657b20c5a76c938612f8409735a8830d257866e <2d8e5168d48a91e7a802d3003e72afb4304bebfa || 6297644db23f77c02ae7961cc542d162629ae2c4 || 7569c4294ba6ff9f194635b14876198f8a687c4a || >=6.1.47 <6.2 || >=6.4.12 <6.5 | ee56da95f8962b86fec4ef93f866e64c8d025a58, 9d383a6fc59271aaaf07a33b23b2eac5b9268b7a, 2d8e5168d48a91e7a802d3003e72afb4304bebfa, 6.2, 6.5 |
| Linux/Linuxgeneric | >=0657b20c5a76c938612f8409735a8830d257866e <77fd40b7ed0c3acf989a0f2a07b15a0a59ea8f96 || >=0657b20c5a76c938612f8409735a8830d257866e <ee56da95f8962b86fec4ef93f866e64c8d025a58 || >=0657b20c5a76c938612f8409735a8830d257866e <9d383a6fc59271aaaf07a33b23b2eac5b9268b7a || >=0657b20c5a76c938612f8409735a8830d257866e <2d8e5168d48a91e7a802d3003e72afb4304bebfa || 6297644db23f77c02ae7961cc542d162629ae2c4 || 7569c4294ba6ff9f194635b14876198f8a687c4a || >=6.1.47 <6.2 || >=6.4.12 <6.5 | 77fd40b7ed0c3acf989a0f2a07b15a0a59ea8f96, ee56da95f8962b86fec4ef93f866e64c8d025a58, 9d383a6fc59271aaaf07a33b23b2eac5b9268b7a, 2d8e5168d48a91e7a802d3003e72afb4304bebfa, 6.2, 6.5 |
| Linux/Linuxgeneric | >=6297644db23f77c02ae7961cc542d162629ae2c4 <3232bdf8a135877345c25bf4c0d892334a4c03f7 || >=0657b20c5a76c938612f8409735a8830d257866e <77fd40b7ed0c3acf989a0f2a07b15a0a59ea8f96 || >=0657b20c5a76c938612f8409735a8830d257866e <ee56da95f8962b86fec4ef93f866e64c8d025a58 || >=0657b20c5a76c938612f8409735a8830d257866e <9d383a6fc59271aaaf07a33b23b2eac5b9268b7a || >=0657b20c5a76c938612f8409735a8830d257866e <2d8e5168d48a91e7a802d3003e72afb4304bebfa || 7569c4294ba6ff9f194635b14876198f8a687c4a || >=6.1.47 <6.1.191 || >=6.4.12 <6.5 | 3232bdf8a135877345c25bf4c0d892334a4c03f7, 77fd40b7ed0c3acf989a0f2a07b15a0a59ea8f96, ee56da95f8962b86fec4ef93f866e64c8d025a58, 9d383a6fc59271aaaf07a33b23b2eac5b9268b7a, 2d8e5168d48a91e7a802d3003e72afb4304bebfa, 6.1.191, 6.5 |
Published upstream
Apr 16, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 30, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix block group refcount race in btrfs_create_pending_block_groups() Block group creation is done in two phases, which results in a slightly unintuitive property: a block group can be allocated/deallocated from after btrfs_make_block_group() adds it to the space_info with btrfs_add_bg_to_space_info(), but before creation is completely completed in btrfs_create_pending_block_groups(). As a result, it is possible for a block group to go unused and have 'btrfs_mark_bg_unused' called on it concurrently with 'btrfs_create_pending_block_groups'. This causes a number of issues, which were fixed with the block group flag 'BLOCK_GROUP_FLAG_NEW'. However, this fix is not quite complete. Since it does not use the unused_bg_lock, it is possible for the following race to occur: btrfs_create_pending_block_groups btrfs_mark_bg_unused if list_empty // false list_del_init clear_bit else if (test_bit) // true list_move_tail And we get into the exact same broken ref count and invalid new_bgs state for transaction cleanup that BLOCK_GROUP_FLAG_NEW was designed to prevent. The broken refcount aspect will result in a warning like: [1272.943527] refcount_t: underflow; use-after-free. [1272.943967] WARNING: CPU: 1 PID: 61 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x110 [1272.944731] Modules linked in: btrfs virtio_net xor zstd_compress raid6_pq null_blk [last unloaded: btrfs] [1272.945550] CPU: 1 UID: 0 PID: 61 Comm: kworker/u32:1 Kdump: loaded Tainted: G W 6.14.0-rc5+ #108 [1272.946368] Tainted: [W]=WARN [1272.946585] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [1272.947273] Workqueue: btrfs_discard btrfs_discard_workfn [btrfs] [1272.947788] RIP: 0010:refcount_warn_saturate+0xba/0x110 [1272.949532] RSP: 0018:ffffbf1200247df0 EFLAGS: 00010282 [1272.949901] RAX: 0000000000000000 RBX: ffffa14b00e3f800 RCX: 0000000000000000 [1272.950437] RDX: 0000000000000000 RSI: ffffbf1200247c78 RDI: 00000000ffffdfff [1272.950986] RBP: ffffa14b00dc2860 R08: 00000000ffffdfff R09: ffffffff90526268 [1272.951512] R10: ffffffff904762c0 R11: 0000000063666572 R12: ffffa14b00dc28c0 [1272.952024] R13: 0000000000000000 R14: ffffa14b00dc2868 R15: 000001285dcd12c0 [1272.952850] FS: 0000000000000000(0000) GS:ffffa14d33c40000(0000) knlGS:0000000000000000 [1272.953458] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [1272.953931] CR2: 00007f838cbda000 CR3: 000000010104e000 CR4: 00000000000006f0 [1272.954474] Call Trace: [1272.954655] <TASK> [1272.954812] ? refcount_warn_saturate+0xba/0x110 [1272.955173] ? __warn.cold+0x93/0xd7 [1272.955487] ? refcount_warn_saturate+0xba/0x110 [1272.955816] ? report_bug+0xe7/0x120 [1272.956103] ? handle_bug+0x53/0x90 [1272.956424] ? exc_invalid_op+0x13/0x60 [1272.956700] ? asm_exc_invalid_op+0x16/0x20 [1272.957011] ? refcount_warn_saturate+0xba/0x110 [1272.957399] btrfs_discard_cancel_work.cold+0x26/0x2b [btrfs] [1272.957853] btrfs_put_block_group.cold+0x5d/0x8e [btrfs] [1272.958289] btrfs_discard_workfn+0x194/0x380 [btrfs] [1272.958729] process_one_work+0x130/0x290 [1272.959026] worker_thread+0x2ea/0x420 [1272.959335] ? __pfx_worker_thread+0x10/0x10 [1272.959644] kthread+0xd7/0x1c0 [1272.959872] ? __pfx_kthread+0x10/0x10 [1272.960172] ret_from_fork+0x30/0x50 [1272.960474] ? __pfx_kthread+0x10/0x10 [1272.960745] ret_from_fork_asm+0x1a/0x30 [1272.961035] </TASK> [1272.961238] ---[ end trace 0000000000000000 ]--- Though we have seen them in the async discard workfn as well. It is most likely to happen after a relocation finishes which cancels discard, tears down the block group, etc. Fix this fully by taking the lock arou ---truncated---
Quoted source text, attributed separately from HOL analysis.