CVE-2026-31654Disclosure(linux / linux_kernel)

LOWCVSS 5.5 · MEDIUM

Signal is active with 2 mentions in latest observed window

Immediate actions

  • Patch linux linux_kernel systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

In the Linux kernel, the following vulnerability has been resolved: mm/vma: fix memory leak in __mmap_region() commit 605f6586ecf7 ("mm/vma: do not leak memory when .mmap_prepare swaps the file") handled the success path by skipping get_file() via file_doesnt_need_get, but missed the error path. When /dev/zero is mmap'd with MAP_SHARED, mmap_zero_prepare() calls shmem_zero_setup_desc() which allocates a new shmem file to back the mapping. If __mmap_new_vma() subsequently fails, this replacement file is never fput()'d - the original is released by ksys_mmap_pgoff(), but nobody releases the new one. Add fput() for the swapped file in the error path. Reproducible with fault injection. FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 CPU: 2 UID: 0 PID: 366 Comm: syz.7.14 Not tainted 7.0.0-rc6 #2 PREEMPT(full) Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x164/0x1f0 should_fail_ex+0x525/0x650 should_failslab+0xdf/0x140 kmem_cache_alloc_noprof+0x78/0x630 vm_area_alloc+0x24/0x160 __mmap_region+0xf6b/0x2660 mmap_region+0x2eb/0x3a0 do_mmap+0xc79/0x1240 vm_mmap_pgoff+0x252/0x4c0 ksys_mmap_pgoff+0xf8/0x120 __x64_sys_mmap+0x12a/0x190 do_syscall_64+0xa9/0x580 entry_SYSCALL_64_after_hwframe+0x76/0x7e </TASK> kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak) BUG: memory leak unreferenced object 0xffff8881118aca80 (size 360): comm "syz.7.14", pid 366, jiffies 4294913255 hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... ff ff ff ff ff ff ff ff c0 28 4d ae ff ff ff ff .........(M..... backtrace (crc db0f53bc): kmem_cache_alloc_noprof+0x3ab/0x630 alloc_empty_file+0x5a/0x1e0 alloc_file_pseudo+0x135/0x220 __shmem_file_setup+0x274/0x420 shmem_zero_setup_desc+0x9c/0x170 mmap_zero_prepare+0x123/0x140 __mmap_region+0xdda/0x2660 mmap_region+0x2eb/0x3a0 do_mmap+0xc79/0x1240 vm_mmap_pgoff+0x252/0x4c0 ksys_mmap_pgoff+0xf8/0x120 __x64_sys_mmap+0x12a/0x190 do_syscall_64+0xa9/0x580 entry_SYSCALL_64_after_hwframe+0x76/0x7e Found by syzkaller.

0.5/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-401

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • linux_kernel

Threat summary

  • Patch or workaround signal is available
  • 2 mentions across 1 observed day

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 2 signals
  • Disclosure: 1 classified signal
  • 2 total mentions across 1 day

Affected systems

Vendors
Products
linux_kernel

2 versions affected across 1 product

Deep dive

Activity timeline2 mentions / 1d
01122Mentions · 2026-04-24: 2Patch / Workaround · 2026-04-24: 1Technical Details · 2026-04-24: 204-24
Signal classification2 categories
Disclosure
150.0%
Patch
150.0%
Referenced assets3 URLs
Full discourse2 posts
  • Vulmon Vulnerability Feed@VulmonFeeds
    Disclosure

    CVE-2026-31654 Memory Leak in Linux Kernel __mmap_region() Function During MAP_S... https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-31654 Customizable Vulnerability Alerts: https://alerts.vulmon.com/?utm_source=twitter&utm_medium=social&utm_campaign=2102281&utm_content=4

    Post summary

    The tweet announces a memory leak vulnerability (CVE‑2026‑31654) in the Linux kernel’s __mmap_region() function, providing a brief technical description but no further details on exploits or patches.

    0000047
    4.0K followersView on X
  • CVE@CVEnew
    Patch

    CVE-2026-31654 In the Linux kernel, the following vulnerability has been resolved: mm/vma: fix memory leak in __mmap_region() commit 605f6586ecf7 ("mm/vma: do not leak memory when… https://www.cve.org/CVERecord?id=CVE-2026-31654

    Post summary

    CVE-2026-31654 is a memory‑leak vulnerability in the Linux kernel's __mmap_region; the issue has been fixed by commit 605f6586ecf7, with no evidence of active exploitation or a PoC.

    0000071
    57.2K followersView on X
CPE platform detail9 entries

9 of 9 entries

PartVendorProductVersionTarget SWTarget HW
OSlinuxlinux_kernel---
OSlinuxlinux_kernel6.19--
OSlinuxlinux_kernel7.0--
OSlinuxlinux_kernel7.0--
OSlinuxlinux_kernel7.0--
OSlinuxlinux_kernel7.0--
OSlinuxlinux_kernel7.0--
OSlinuxlinux_kernel7.0--
OSlinuxlinux_kernel7.0--

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