Vulnerabilidad · Publicado 08/06/2026 · Actualizado 01/08/2026
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 …
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
Score: 7.8/10 — Severidad: HIGH — Estado NIST: Analyzed
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Linux kernel — Linux
CWE-787
Publicado en NIST NVD.