btrfs: correct the order of prelim_ref arguments in btrfs__prelim_ref
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-476.
Summary
In the Linux kernel, the following vulnerability has been resolved: btrfs: correct the order of prelim_ref arguments in btrfs__prelim_ref btrfs_prelim_ref() calls the old and new reference variables in the incorrect order. This causes a NULL pointer dereference because oldref is passed as NULL to trace_btrfs_prelim_ref_insert(). Note, trace_btrfs_prelim_ref_insert() is being called with newref as oldref (and oldref as NULL) on purpose in order to print out the values of newref. To reproduce: echo 1 > /sys/kernel/debug/tracing/events/btrfs/btrfs_prelim_ref_insert/enable Perform some writeback operations. Backtrace: BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 115949067 P4D 115949067 PUD 11594a067 PMD 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 1 UID: 0 PID: 1188 Comm: fsstress Not tainted 6.15.0-rc2-tester+ #47 PREEMPT(voluntary) 7ca2cef72d5e9c600f0c7718adb6462de8149622 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-2-gc13ff2cd-prebuilt.qemu.org 04/01/2014 RIP: 0010:trace_event_raw_event_btrfs__prelim_ref+0x72/0x130 Code: e8 43 81 9f ff 48 85 c0 74 78 4d 85 e4 0f 84 8f 00 00 00 49 8b 94 24 c0 06 00 00 48 8b 0a 48 89 48 08 48 8b 52 08 48 89 50 10 <49> 8b 55 18 48 89 50 18 49 8b 55 20 48 89 50 20 41 0f b6 55 28 88 RSP: 0018:ffffce44820077a0 EFLAGS: 00010286 RAX: ffff8c6b403f9014 RBX: ffff8c6b55825730 RCX: 304994edf9cf506b RDX: d8b11eb7f0fdb699 RSI: ffff8c6b403f9010 RDI: ffff8c6b403f9010 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000010 R10: 00000000ffffffff R11: 0000000000000000 R12: ffff8c6b4e8fb000 R13: 0000000000000000 R14: ffffce44820077a8 R15: ffff8c6b4abd1540 FS: 00007f4dc6813740(0000) GS:ffff8c6c1d378000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000018 CR3: 000000010eb42000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> prelim_ref_insert+0x1c1/0x270 find_parent_nodes+0x12a6/0x1ee0 ? __entry_text_end+0x101f06/0x101f09 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 btrfs_is_data_extent_shared+0x167/0x640 ? fiemap_process_hole+0xd0/0x2c0 extent_fiemap+0xa5c/0xbc0 ? __entry_text_end+0x101f05/0x101f09 btrfs_fiemap+0x7e/0xd0 do_vfs_ioctl+0x425/0x9d0 __x64_sys_ioctl+0x75/0xc0
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 4.14 and later | 5.4.294, 5.10.238, 5.15.185, 6.1.141, 6.6.93, 6.12.31, 6.14.9, 6.15 | Patch available | CNA |
- Linux VendorLinux Affected 4.14 and later Fixed in 5.4.294, 5.10.238, 5.15.185, 6.1.141, 6.6.93, 6.12.31, 6.14.9, 6.15 Patch available CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 5.4.294; 5.5 to before 5.10.238; 5.11 to before 5.15.185; 5.16 to before 6.1.141; 6.2 to before 6.6.93; 6.7 to before 6.12.31; 6.13 to before 6.14.9 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:* | 6.15 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:* | 6.15 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:* | 6.15 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:* | 6.15 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:* | 6.15 rc5 | Vulnerable | Linux |
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | 11.0 | Vulnerable | Debian |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 5.4.294; 5.5 to before 5.10.238; 5.11 to before 5.15.185; 5.16 to before 6.1.141; 6.2 to before 6.6.93; 6.7 to before 6.12.31; 6.13 to before 6.14.9 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:* Versions 6.15 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:* Versions 6.15 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:* Versions 6.15 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:* Versions 6.15 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:* Versions 6.15 rc5 Vulnerable ·Linux
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.4.294, 5.10.238, 5.15.185, 6.1.141, 6.6.93, 6.12.31, 6.14.9, 6.15
Vendor assessments
Red Hat
Not affected: 5 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2025-38034
- 2026-10-03 Alias added: GHSA-q9x5-5x5x-rgj4
References
Patch 8
- https://git.kernel.org/stable/c/5755b6731655e248c4f1d52a2e1b18795b4a2a3a
- https://git.kernel.org/stable/c/a641154cedf9d69730f8af5d0a901fe86e6486bd
- https://git.kernel.org/stable/c/a876703894a6dd6e8c04b0635d86e9f7a7c81b79
- https://git.kernel.org/stable/c/0528bba48dce7820d2da72e1a114e1c4552367eb
- https://git.kernel.org/stable/c/7a97f961a568a8f72472dc804af02a0f73152c5f
- https://git.kernel.org/stable/c/7f7c8c03feba5f2454792fab3bb8bd45bd6883f9
- https://git.kernel.org/stable/c/137bfa08c6441f324d00692d1e9d22cfd773329b
- https://git.kernel.org/stable/c/bc7e0975093567f51be8e1bdf4aa5900a3cf0b1e
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- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2025-38034 · CVE Program
- CVE-2025-38034 · NVD
- FIRST EPSS
- GHSA-q9x5-5x5x-rgj4 · GitHub Advisory Database · CC BY 4.0
- CVE-2025-38034 · Red Hat security data · CC BY 4.0
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