{"cve":"CVE-2026-31654","nvd":{"published":"2026-04-24T15:16:44.890","modified":"2026-06-17T10:34:10.353","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/vma: fix memory leak in __mmap_region()\n\ncommit 605f6586ecf7 (\"mm/vma: do not leak memory when .mmap_prepare\nswaps the file\") handled the success path by skipping get_file() via\nfile_doesnt_need_get, but missed the error path.\n\nWhen /dev/zero is mmap'd with MAP_SHARED, mmap_zero_prepare() calls\nshmem_zero_setup_desc() which allocates a new shmem file to back the\nmapping. If __mmap_new_vma() subsequently fails, this replacement\nfile is never fput()'d - the original is released by\nksys_mmap_pgoff(), but nobody releases the new one.\n\nAdd fput() for the swapped file in the error path.\n\nReproducible with fault injection.\n\nFAULT_INJECTION: forcing a failure.\nname failslab, interval 1, probability 0, space 0, times 1\nCPU: 2 UID: 0 PID: 366 Comm: syz.7.14 Not tainted 7.0.0-rc6 #2 PREEMPT(full)\nHardware 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\nCall Trace:\n <TASK>\n dump_stack_lvl+0x164/0x1f0\n should_fail_ex+0x525/0x650\n should_failslab+0xdf/0x140\n kmem_cache_alloc_noprof+0x78/0x630\n vm_area_alloc+0x24/0x160\n __mmap_region+0xf6b/0x2660\n mmap_region+0x2eb/0x3a0\n do_mmap+0xc79/0x1240\n vm_mmap_pgoff+0x252/0x4c0\n ksys_mmap_pgoff+0xf8/0x120\n __x64_sys_mmap+0x12a/0x190\n do_syscall_64+0xa9/0x580\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n </TASK>\n\nkmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)\nBUG: memory leak\nunreferenced object 0xffff8881118aca80 (size 360):\n  comm \"syz.7.14\", pid 366, jiffies 4294913255\n  hex dump (first 32 bytes):\n    00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00  .....N..........\n    ff ff ff ff ff ff ff ff c0 28 4d ae ff ff ff ff  .........(M.....\n  backtrace (crc db0f53bc):\n    kmem_cache_alloc_noprof+0x3ab/0x630\n    alloc_empty_file+0x5a/0x1e0\n    alloc_file_pseudo+0x135/0x220\n    __shmem_file_setup+0x274/0x420\n    shmem_zero_setup_desc+0x9c/0x170\n    mmap_zero_prepare+0x123/0x140\n    __mmap_region+0xdda/0x2660\n    mmap_region+0x2eb/0x3a0\n    do_mmap+0xc79/0x1240\n    vm_mmap_pgoff+0x252/0x4c0\n    ksys_mmap_pgoff+0xf8/0x120\n    __x64_sys_mmap+0x12a/0x190\n    do_syscall_64+0xa9/0x580\n    entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nFound by syzkaller.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-401"],"references":["https://git.kernel.org/stable/c/61fc8eaf2ab214b32c7bce52597c80cf0ca41ada","https://git.kernel.org/stable/c/894f99eb535edc4514f756818f3c4f688ba53a59"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:33:09.003606135+00:00"},"epss":{"cve":"CVE-2026-31654","score":0.00113,"percentile":0.01408,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}