CVE-2024-26638

nbd: always initialize struct msghdr completely

Published Mar 18, 2024 CVSS 3.1 · 4.4 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

nbd: always initialize struct msghdr completely

syzbot complains that msg->msg_get_inq value can be uninitialized [1]

struct msghdr got many new fields recently, we should always make
sure their values is zero by default.

[1]
BUG: KMSAN: uninit-value in tcp_recvmsg+0x686/0xac0 net/ipv4/tcp.c:2571
tcp_recvmsg+0x686/0xac0 net/ipv4/tcp.c:2571
inet_recvmsg+0x131/0x580 net/ipv4/af_inet.c:879
sock_recvmsg_nosec net/socket.c:1044 [inline]
sock_recvmsg+0x12b/0x1e0 net/socket.c:1066
__sock_xmit+0x236/0x5c0 drivers/block/nbd.c:538
nbd_read_reply drivers/block/nbd.c:732 [inline]
recv_work+0x262/0x3100 drivers/block/nbd.c:863
process_one_work kernel/workqueue.c:2627 [inline]
process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2700
worker_thread+0xf45/0x1490 kernel/workqueue.c:2781
kthread+0x3ed/0x540 kernel/kthread.c:388
ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

Local variable msg created at:
__sock_xmit+0x4c/0x5c0 drivers/block/nbd.c:513
nbd_read_reply drivers/block/nbd.c:732 [inline]
recv_work+0x262/0x3100 drivers/block/nbd.c:863

CPU: 1 PID: 7465 Comm: kworker/u5:1 Not tainted 6.7.0-rc7-syzkaller-00041-gf016f7547aee #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Workqueue: nbd5-recv recv_work

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-6818-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6818-2 Linux kernel (ARM laptop) vulnerabilities
Ubuntu USN Ubuntu USN USN-6818-3 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-6818-4 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-6819-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6819-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6819-3 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-6819-4 Linux kernel (Oracle) vulnerabilities
History
Type Values Removed Values Added
First Time appeared Redhat rhel Eus
CPEs cpe:/a:redhat:rhel_eus:9.4
Vendors & Products Redhat rhel Eus
Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-908
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Type Values Removed Values Added
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/o:redhat:enterprise_linux:8
Vendors & Products Redhat
Redhat enterprise Linux
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
May 11, 2026, 8:01 PM
Reserved
Feb 19, 2024, 2:20 PM
Status
Analyzed
Published
Mar 18, 2024, 11:15 AM
Modified
Jun 17, 2026, 7:17 AM
Severity
Low
Public date
Mar 18, 2024, 12:00 AM