CVE-2026-64449staging: vme_user: bound slave read/write to the kern_buf size
Updated under an hour ago ()
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In the Linux kernel, the following vulnerability has been resolved: staging: vme_user: bound slave read/write to the kern_buf size The SLAVE-path helpers buffer_to_user() and buffer_from_user() copy 'count' bytes into/out of the fixed-size kern_buf (size_buf == PCI_BUF_SIZE == 0x20000, 128 KiB) using *ppos as the offset, without bounding *ppos + count against size_buf. vme_user_write()/vme_user_read() only clamp count to the VME window size (image_size = vme_get_size(resource)), which VME_SET_SLAVE sets from the user-supplied slave.size -- validated against the VME address space (up to VME_A32_MAX = 4 GiB), not against PCI_BUF_SIZE. When the window exceeds 128 KiB, a write()/read() copies past the kern_buf allocation. Clamp count against size_buf in both helpers, with an early return when *ppos is already at/after the buffer end. *ppos is >= 0 here (the caller rejects negative offsets), so size_buf - *ppos cannot wrap. This mirrors the existing clamp in the MASTER-path helpers resource_to_user() / resource_from_user(), and matches the read()/write() convention of a short transfer at end-of-buffer. Found by static analysis (CodeQL taint tracking + CBMC bounded model checking) and confirmed dynamically under KASAN with the vme_fake bridge: BUG: KASAN: slab-out-of-bounds in _copy_from_user+0x2d/0x80 Write of size 262144 at addr ffff888004100000 by task trigger/68 _copy_from_user+0x2d/0x80 vme_user_write+0x13e/0x240 [vme_user] vfs_write+0x1b8/0x7a0 ksys_write+0xb8/0x150
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Analyzed
- Record last updated
- Aug 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from f00a86d98a1ec3e99d352cda926fab767ba43b1f before 65358d89dc9f1c25d9364b2b3ef0f3b47717f9ed; from f00a86d98a1ec3e99d352cda926fab767ba43b1f before adc8b9c30d716c362646edb45662aa1c641a154a; from f00a86d98a1ec3e99d352cda926fab767ba43b1f before 8eff7cd4817e14dbe3b9952cce55ef52d1d38940; from f00a86d98a1ec3e99d352cda926fab767ba43b1f before e99f2df433c63c86c93de1e5f08f16e404388756; from f00a86d98a1ec3e99d352cda926fab767ba43b1f before 1b495fa0d4927c88d88bf346bf311f2e26e860ed; from f00a86d98a1ec3e99d352cda926fab767ba43b1f before 9f32f38265014fac7f5dc9490fb01a638ce6e121 | CNA record |
linux linux_kernel linux:linux_kernel | from 2.6.32 before 6.1.178; from 6.2 before 6.6.145; from 6.7 before 6.12.96; from 6.13 before 6.18.39; from 6.19 before 7.1.4; 7.2; 7.2 | NVD |
References
- https://git.kernel.org/stable/c/65358d89dc9f1c25d9364b2b3ef0f3b47717f9edpatch
- https://git.kernel.org/stable/c/adc8b9c30d716c362646edb45662aa1c641a154apatch
- https://git.kernel.org/stable/c/8eff7cd4817e14dbe3b9952cce55ef52d1d38940patch
- https://git.kernel.org/stable/c/e99f2df433c63c86c93de1e5f08f16e404388756patch
- https://git.kernel.org/stable/c/1b495fa0d4927c88d88bf346bf311f2e26e860edpatch
- https://git.kernel.org/stable/c/9f32f38265014fac7f5dc9490fb01a638ce6e121patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.