{"cve":"CVE-2024-26870","nvd":{"published":"2024-04-17T11:15:09.460","modified":"2026-10-15T01:17:26.880","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSv4.2: fix nfs4_listxattr kernel BUG at mm/usercopy.c:102\n\nA call to listxattr() with a buffer size = 0 returns the actual\nsize of the buffer needed for a subsequent call. When size > 0,\nnfs4_listxattr() does not return an error because either\ngeneric_listxattr() or nfs4_listxattr_nfs4_label() consumes\nexactly all the bytes then size is 0 when calling\nnfs4_listxattr_nfs4_user() which then triggers the following\nkernel BUG:\n\n  [   99.403778] kernel BUG at mm/usercopy.c:102!\n  [   99.404063] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP\n  [   99.408463] CPU: 0 PID: 3310 Comm: python3 Not tainted 6.6.0-61.fc40.aarch64 #1\n  [   99.415827] Call trace:\n  [   99.415985]  usercopy_abort+0x70/0xa0\n  [   99.416227]  __check_heap_object+0x134/0x158\n  [   99.416505]  check_heap_object+0x150/0x188\n  [   99.416696]  __check_object_size.part.0+0x78/0x168\n  [   99.416886]  __check_object_size+0x28/0x40\n  [   99.417078]  listxattr+0x8c/0x120\n  [   99.417252]  path_listxattr+0x78/0xe0\n  [   99.417476]  __arm64_sys_listxattr+0x28/0x40\n  [   99.417723]  invoke_syscall+0x78/0x100\n  [   99.417929]  el0_svc_common.constprop.0+0x48/0xf0\n  [   99.418186]  do_el0_svc+0x24/0x38\n  [   99.418376]  el0_svc+0x3c/0x110\n  [   99.418554]  el0t_64_sync_handler+0x120/0x130\n  [   99.418788]  el0t_64_sync+0x194/0x198\n  [   99.418994] Code: aa0003e3 d000a3e0 91310000 97f49bdb (d4210000)\n\nIssue is reproduced when generic_listxattr() returns 'system.nfs4_acl',\nthus calling lisxattr() with size = 16 will trigger the bug.\n\nAdd check on nfs4_listxattr() to return ERANGE error when it is\ncalled with size > 0 and the return value is greater than size.","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":[],"references":["https://git.kernel.org/stable/c/06e828b3f1b206de08ef520fc46a40b22e1869cb","https://git.kernel.org/stable/c/23bfecb4d852751d5e403557dd500bb563313baf","https://git.kernel.org/stable/c/251a658bbfceafb4d58c76b77682c8bf7bcfad65","https://git.kernel.org/stable/c/4403438eaca6e91f02d272211c4d6b045092396b","https://git.kernel.org/stable/c/79cdcc765969d23f4e3d6ea115660c3333498768"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:49:08.435428910+00:00"},"epss":{"cve":"CVE-2024-26870","score":0.00283,"percentile":0.20667,"date":"2026-10-25"},"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."]}