CVE-2022-50299: md: Replace snprintf with scnprintf

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-09-15 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: md: Replace snprintf with scnprintf Current code produces a warning as shown below when total characters in the constituent block device names plus the slashes exceeds 200. snprintf() returns the number of characters generated from the given input, which could cause the expression “200 – len” to wrap around to a large positive number. Fix this by using scnprintf() instead, which returns the actual number of characters written into the buffer. [ 1513.267938] ------------[ cut here ]------------ [ 1513.267943] WARNING: CPU: 15 PID: 37247 at <snip>/lib/vsprintf.c:2509 vsnprintf+0x2c8/0x510 [ 1513.267944] Modules linked in: <snip> [ 1513.267969] CPU: 15 PID: 37247 Comm: mdadm Not tainted 5.4.0-1085-azure #90~18.04.1-Ubuntu [ 1513.267969] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 05/09/2022 [ 1513.267971] RIP: 0010:vsnprintf+0x2c8/0x510 <-snip-> [ 1513.267982] Call Trace: [ 1513.267986] snprintf+0x45/0x70 [ 1513.267990] ? disk_name+0x71/0xa0 [ 1513.267993] dump_zones+0x114/0x240 [raid0] [ 1513.267996] ? _cond_resched+0x19/0x40 [ 1513.267998] raid0_run+0x19e/0x270 [raid0] [ 1513.268000] md_run+0x5e0/0xc50 [ 1513.268003] ? security_capable+0x3f/0x60 [ 1513.268005] do_md_run+0x19/0x110 [ 1513.268006] md_ioctl+0x195e/0x1f90 [ 1513.268007] blkdev_ioctl+0x91f/0x9f0 [ 1513.268010] block_ioctl+0x3d/0x50 [ 1513.268012] do_vfs_ioctl+0xa9/0x640 [ 1513.268014] ? __fput+0x162/0x260 [ 1513.268016] ksys_ioctl+0x75/0x80 [ 1513.268017] __x64_sys_ioctl+0x1a/0x20 [ 1513.268019] do_syscall_64+0x5e/0x200 [ 1513.268021] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Affected products

Linux kernel: from 4.10 before 4.14.296; from 4.15 before 4.19.262; from 4.20 before 5.4.220; from 5.5 before 5.10.150; from 5.11 before 5.15.75; from 5.16 before 5.19.17 — fixed in 4.14.296, 4.19.262, 5.10.150, 5.15.75, 5.19.17, 5.4.220

How to fix

Upgrade to a fixed version: Linux kernel 4.14.296, 4.19.262, 5.10.150, 5.15.75. Check the vendor advisory for mitigations.

References

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