Not yet scoredPublished Jul 19, 2026

CVE-2026-63810block: Avoid mounting the bdev pseudo-filesystem in userspace

Updated under an hour ago (Oct 28, 2026, 5:50 AM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: block: Avoid mounting the bdev pseudo-filesystem in userspace The bdev pseudo-filesystem is an internal kernel filesystem with which userspace should not interfere. Unregister it so that userspace cannot even attempt to mount it. This fixes a bug [1] that occurs when attempting to access files, because the system call move_mount() uses pointers declared in the inode_operations structure, which for the bdev pseudo-filesystem are always equal to 0. `inode->i_op = &empty_iops;` [1] BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 23380067 P4D 23380067 PUD 23381067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN NOPTI CPU: 2 PID: 17125 Comm: syz-executor.0 Not tainted 6.1.155-syzkaller-00350-g84221fde2681 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:0x0 Call Trace: <TASK> lookup_open.isra.0+0x700/0x1180 fs/namei.c:3460 open_last_lookups fs/namei.c:3550 [inline] path_openat+0x953/0x2700 fs/namei.c:3780 do_filp_open+0x1c5/0x410 fs/namei.c:3810 do_sys_openat2+0x171/0x4d0 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x13c/0x1f0 fs/open.c:1345 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

CVSS: Not yet scored
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Awaiting Analysis
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 3d3fcf23993bb756de2f912ab631cfdcc4746554; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 99cde0a7b1e98fd3970aabef1300918e91698dd5; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 builds before 1a02a5028bd6dead1f8503854ef3168d651cd417; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 197971e6ffc0a6356b2ba2b22beb42bc0f7e412d; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 3804e6de30ae7b053d53341d9d6944356cf23b40; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 717f721eb67d2dacd3ed5f7495aef2f442e84ce4; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before f73aa66dffcb8e61e78f01b56163ec16a15d06d2	CNA record
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP

References

References

https://git.kernel.org/stable/c/3d3fcf23993bb756de2f912ab631cfdcc4746554
https://git.kernel.org/stable/c/99cde0a7b1e98fd3970aabef1300918e91698dd5
https://git.kernel.org/stable/c/1a02a5028bd6dead1f8503854ef3168d651cd417
https://git.kernel.org/stable/c/197971e6ffc0a6356b2ba2b22beb42bc0f7e412d
https://git.kernel.org/stable/c/3804e6de30ae7b053d53341d9d6944356cf23b40
https://git.kernel.org/stable/c/717f721eb67d2dacd3ed5f7495aef2f442e84ce4
https://git.kernel.org/stable/c/f73aa66dffcb8e61e78f01b56163ec16a15d06d2
https://cert-portal.siemens.com/productcert/html/ssa-019113.html
https://cert-portal.siemens.com/productcert/html/ssa-457936.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.