{"cve":"CVE-2025-40235","nvd":{"published":"2025-12-04T16:16:16.407","modified":"2026-10-19T21:10:00.160","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: directly free partially initialized fs_info in btrfs_check_leaked_roots()\n\nIf fs_info->super_copy or fs_info->super_for_commit allocated failed in\nbtrfs_get_tree_subvol(), then no need to call btrfs_free_fs_info().\nOtherwise btrfs_check_leaked_roots() would access NULL pointer because\nfs_info->allocated_roots had not been initialised.\n\nsyzkaller reported the following information:\n  ------------[ cut here ]------------\n  BUG: unable to handle page fault for address: fffffffffffffbb0\n  #PF: supervisor read access in kernel mode\n  #PF: error_code(0x0000) - not-present page\n  PGD 64c9067 P4D 64c9067 PUD 64cb067 PMD 0\n  Oops: Oops: 0000 [#1] SMP KASAN PTI\n  CPU: 0 UID: 0 PID: 1402 Comm: syz.1.35 Not tainted 6.15.8 #4 PREEMPT(lazy)\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), (...)\n  RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]\n  RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]\n  RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]\n  RIP: 0010:refcount_read include/linux/refcount.h:170 [inline]\n  RIP: 0010:btrfs_check_leaked_roots+0x18f/0x2c0 fs/btrfs/disk-io.c:1230\n  [...]\n  Call Trace:\n   <TASK>\n   btrfs_free_fs_info+0x310/0x410 fs/btrfs/disk-io.c:1280\n   btrfs_get_tree_subvol+0x592/0x6b0 fs/btrfs/super.c:2029\n   btrfs_get_tree+0x63/0x80 fs/btrfs/super.c:2097\n   vfs_get_tree+0x98/0x320 fs/super.c:1759\n   do_new_mount+0x357/0x660 fs/namespace.c:3899\n   path_mount+0x716/0x19c0 fs/namespace.c:4226\n   do_mount fs/namespace.c:4239 [inline]\n   __do_sys_mount fs/namespace.c:4450 [inline]\n   __se_sys_mount fs/namespace.c:4427 [inline]\n   __x64_sys_mount+0x28c/0x310 fs/namespace.c:4427\n   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n   do_syscall_64+0x92/0x180 arch/x86/entry/syscall_64.c:94\n   entry_SYSCALL_64_after_hwframe+0x76/0x7e\n  RIP: 0033:0x7f032eaffa8d\n  [...]","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/0c2b2d4d053e9840e6da6ed581befa20309f281a","https://git.kernel.org/stable/c/17679ac6df6c4830ba711835aa8cf961be36cfa1","https://git.kernel.org/stable/c/b1c2b4e6ffd307720ab6ce42f6749b0c02ba0a73"],"products":[],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-40235","score":0.00199,"percentile":0.09585,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}