CVE-2025-40235: btrfs: directly free partially initialized fs_info in btrfs_check_leaked_roots()
Vulnerability summary
CVE-2025-40235 is a vulnerability in linux with no CVSS score yet. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.5% of scored vulnerabilities.
No CVSS vector published; no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 20 · Related 20Timeline
- 04-12-2025PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: directly free partially initialized fs_info in btrfs_check_leaked_roots() If fs_info->super_copy or fs_info->super_for_commit allocated failed in btrfs_get_tree_subvol(), then no need to call btrfs_free_fs_info(). Otherwise btrfs_check_leaked_roots() would access NULL pointer because fs_info->allocated_roots had not been initialised. syzkaller reported the following information: ------------[ cut here ]------------ BUG: unable to handle page fault for address: fffffffffffffbb0 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 64c9067 P4D 64c9067 PUD 64cb067 PMD 0 Oops: Oops: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 1402 Comm: syz.1.35 Not tainted 6.15.8 #4 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), (...) RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] RIP: 0010:refcount_read include/linux/refcount.h:170 [inline] RIP: 0010:btrfs_check_leaked_roots+0x18f/0x2c0 fs/btrfs/disk-io.c:1230 [...] Call Trace: <TASK> btrfs_free_fs_info+0x310/0x410 fs/btrfs/disk-io.c:1280 btrfs_get_tree_subvol+0x592/0x6b0 fs/btrfs/super.c:2029 btrfs_get_tree+0x63/0x80 fs/btrfs/super.c:2097 vfs_get_tree+0x98/0x320 fs/super.c:1759 do_new_mount+0x357/0x660 fs/namespace.c:3899 path_mount+0x716/0x19c0 fs/namespace.c:4226 do_mount fs/namespace.c:4239 [inline] __do_sys_mount fs/namespace.c:4450 [inline] __se_sys_mount fs/namespace.c:4427 [inline] __x64_sys_mount+0x28c/0x310 fs/namespace.c:4427 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x92/0x180 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f032eaffa8d [...]
CVSS metrics
Risk metrics not yet published.
EPSS trend
Probability
0.20%
Chance of exploitation in the next 30 days
Percentile
10%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.20% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: not stated in public data.
Ubuntu127 products
- linux< 6.8.0-106.106 | < 6.17.0-14.14
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1050.53 | < 6.17.0-1007.7
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian1 product
- linux< 6.12.57-1 | < 6.17.6-1
Linux1 product
- linux≥ 3bb17a25bcb09abbd667c6ac86c7c9109ae82bcd, < b1c2b4e6ffd307720ab6ce42f6749b0c02ba0a73 | ≥ 3bb17a25bcb09abbd667c6ac86c7c9109ae82bcd, < 0c2b2d4d053e9840e6da6ed581befa20309f281a | ≥ 3bb17a25bcb09abbd667c6ac86c7c9109ae82bcd, < 17679ac6df6c4830ba711835aa8cf961be36cfa1 | 6.8
3 vendors · 129 products
