openEuler-SA-2026-2753

Synopsis:

kernel security updateSummary:

An update for kernel is now available for openEuler-20.03-LTS-SP4Description:

The Linux Kernel, the operating system core itself.

Security Fix(es):

In the Linux kernel, the following vulnerability has been resolved:

dm: fix a buffer overflow in ioctl processing

Tony Asleson (using Claude) found a buffer overflow in dm-ioctl in the function retrieve_status:

1. The code in retrieve_status checks that the output string fits into the output buffer and writes the output string there
2. Then, the code aligns the "outptr" variable to the next 8-byte boundary: outptr = align_ptr(outptr);
3. The alignment doesn't check overflow, so outptr could point past the buffer end
4. The "for" loop is iterated again, it executes: remaining = len - (outptr - outbuf);
5. If "outptr" points past "outbuf + len", the arithmetics wraps around and the variable "remaining" contains unusually high number
6. With "remaining" being high, the code writes more data past the end of the buffer

Luckily, this bug has no security implications because:

1. Only root can issue device mapper ioctls
2. The commonly used libraries that communicate with device mapper (libdevmapper and devicemapper-rs) use buffer size that is aligned to 8 bytes - thus, "outptr = align_ptr(outptr)" can't overshoot the input buffer and the bug can't happen accidentally(CVE-2026-46294)Topic:

An update for kernel is now available for openEuler-20.03-LTS-SP4/openEuler-22.03-LTS-SP3/openEuler-24.03-LTS/openEuler-24.03-LTS-SP2.

openEuler Security has rated this update as having a security impact of high. A Common Vunlnerability Scoring System(CVSS)base score,which gives a detailed severity rating, is available for each vulnerability from the CVElink(s) in the References section.Severity:

HighAffected Component:

kernel