CVE-2026-97560

Received Received - Intake

Buffer Overflow in Linux Kernel SMB Client

Publication date: 2026-09-25

Last updated on: 2026-10-03

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix one-byte OOB read in smb2_parse_native_symlink() When parsing a share-root relative native symlink, memcpy copies smb_target+1 (skipping the leading separator) but uses strlen(smb_target)+1 as the length, reading one byte past the allocated buffer. This fixes the following KASAN splat when accessing an SMB symlink with a target of '\a\b': BUG: KASAN: slab-out-of-bounds in smb2_parse_native_symlink+0x4f5/0xca0 Read of size 5 at addr ffff88800878fe21 by task netfsfuzz-execu/1 CPU: 1 UID: 0 PID: 1 Comm: netfsfuzz-execu Tainted: G N 7.2.0-11943-g2709dd5ae32f-dirty #1 PREEMPT(lazy) Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996) Call Trace: <TASK> dump_stack_lvl+0x7b/0xa0 print_report+0xd0/0x630 kasan_report+0xe5/0x120 kasan_check_range+0x105/0x1b0 __asan_memcpy+0x23/0x60 smb2_parse_native_symlink+0x4f5/0xca0 parse_reparse_point+0x68a/0x1530 reparse_info_to_fattr+0x752/0xa20 cifs_get_fattr+0x873/0x15b0 cifs_get_inode_info+0xc0/0x310 cifs_lookup+0x308/0xa70 __lookup_slow+0x122/0x2b0 lookup_slow+0x50/0x70 path_lookupat+0x525/0xaf0 filename_lookup+0x1f2/0x550 vfs_statx+0xd1/0x1a0 vfs_fstatat+0x65/0xc0 __do_sys_newfstatat+0x9a/0x120 do_syscall_64+0xdd/0x4a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-25

Last Modified

2026-10-03

Generated

2026-10-15

AI Q&A

2026-09-25

EPSS Evaluated

2026-10-14

NVD

CVE-2026-97560

EUVD

EUVD-2026-86868

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	7.2.0-11943-g2709dd5ae32f
linux	linux_kernel	7.2.0

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability is a one-byte out-of-bounds (OOB) read in the Linux kernel's SMB client implementation. It occurs when parsing a share-root relative native symlink. The code incorrectly copies data by using strlen(smb_target)+1 as the length but skips the leading separator, causing a read past the allocated buffer.

Detection Guidance

This vulnerability is specific to the Linux kernel's SMB client implementation and may be detected by monitoring for KASAN (Kernel Address Sanitizer) slab-out-of-bounds errors in the smb2_parse_native_symlink function. Check kernel logs for errors like 'BUG: KASAN: slab-out-of-bounds in smb2_parse_native_symlink' after accessing SMB symlinks.

Impact Analysis

This vulnerability could allow an attacker to read one byte of memory outside the intended buffer when accessing an SMB symlink with a specific target. This may lead to information disclosure or potential system instability, though it requires specific conditions to trigger.

Compliance Impact

This vulnerability is a memory corruption issue in the Linux kernel's SMB client implementation. It does not directly relate to data privacy, access controls, or audit logging required by standards like GDPR or HIPAA. The impact is limited to potential system crashes or instability when processing maliciously crafted SMB symlinks, which does not inherently violate compliance requirements.

Mitigation Strategies

Apply the latest Linux kernel security patches that include the fix for CVE-2026-97560. Avoid accessing untrusted SMB shares or symlinks until patched. Monitor vendor advisories for kernel updates.

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