CVE-2024-26638: nbd: always initialize struct msghdr completely
In the Linux kernel, the following vulnerability has been resolved:
nbd: always initialize struct msghdr completely
syzbot complains that msg->msggetinq 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 tcprecvmsg+0x686/0xac0 net/ipv4/tcp.c:2571 tcprecvmsg+0x686/0xac0 net/ipv4/tcp.c:2571 inetrecvmsg+0x131/0x580 net/ipv4/afinet.c:879 sockrecvmsgnosec net/socket.c:1044 [inline] sockrecvmsg+0x12b/0x1e0 net/socket.c:1066 sockxmit+0x236/0x5c0 drivers/block/nbd.c:538 nbdreadreply drivers/block/nbd.c:732 [inline] recvwork+0x262/0x3100 drivers/block/nbd.c:863 processonework kernel/workqueue.c:2627 [inline] processscheduledworks+0x104e/0x1e70 kernel/workqueue.c:2700 workerthread+0xf45/0x1490 kernel/workqueue.c:2781 kthread+0x3ed/0x540 kernel/kthread.c:388 retfromfork+0x66/0x80 arch/x86/kernel/process.c:147 retfromforkasm+0x11/0x20 arch/x86/entry/entry64.S:242
Local variable msg created at: sockxmit+0x4c/0x5c0 drivers/block/nbd.c:513 nbdreadreply drivers/block/nbd.c:732 [inline] recvwork+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 recvwork
Other sources
In the Linux kernel, the following vulnerability has been resolved:
nbd: always initialize struct msghdr completely
The Linux kernel CVE team has assigned CVE-2024-26638 to this issue.
Upstream advisory: https://lore.kernel.org/linux-cve-announce/20240318101458.2835626-16-lee@kernel.org/T
— Red Hat
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2024-26638?
CVE-2024-26638 has been classified as a moderate severity vulnerability due to uninitialized values in the Linux kernel's struct msghdr.
How do I fix CVE-2024-26638?
To fix CVE-2024-26638, update your system to the recommended kernel versions 6.1.76, 6.6.15, 6.7.3, 6.8, or applicable versions from Debian such as 5.10.223-1 or 6.12.12-1.
What software is affected by CVE-2024-26638?
CVE-2024-26638 affects various versions of the Linux kernel on Red Hat and Debian distributions.
What is the nature of CVE-2024-26638 vulnerability?
CVE-2024-26638 is caused by the lack of initialization for the msg->msg_get_inq value in the Linux kernel, which can lead to undefined behavior.
Is CVE-2024-26638 applicable to older kernel versions?
Yes, CVE-2024-26638 can affect older kernel versions prior to the updates that address the uninitialized struct msghdr issue.