{"cve":"CVE-2024-49883","nvd":{"published":"2024-10-21T18:15:11.060","modified":"2026-08-04T11:20:55.747","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: aovid use-after-free in ext4_ext_insert_extent()\n\nAs Ojaswin mentioned in Link, in ext4_ext_insert_extent(), if the path is\nreallocated in ext4_ext_create_new_leaf(), we'll use the stale path and\ncause UAF. Below is a sample trace with dummy values:\n\next4_ext_insert_extent\n  path = *ppath = 2000\n  ext4_ext_create_new_leaf(ppath)\n    ext4_find_extent(ppath)\n      path = *ppath = 2000\n      if (depth > path[0].p_maxdepth)\n            kfree(path = 2000);\n            *ppath = path = NULL;\n      path = kcalloc() = 3000\n      *ppath = 3000;\n      return path;\n  /* here path is still 2000, UAF! */\n  eh = path[depth].p_hdr\n\n==================================================================\nBUG: KASAN: slab-use-after-free in ext4_ext_insert_extent+0x26d4/0x3330\nRead of size 8 at addr ffff8881027bf7d0 by task kworker/u36:1/179\nCPU: 3 UID: 0 PID: 179 Comm: kworker/u6:1 Not tainted 6.11.0-rc2-dirty #866\nCall Trace:\n <TASK>\n ext4_ext_insert_extent+0x26d4/0x3330\n ext4_ext_map_blocks+0xe22/0x2d40\n ext4_map_blocks+0x71e/0x1700\n ext4_do_writepages+0x1290/0x2800\n[...]\n\nAllocated by task 179:\n ext4_find_extent+0x81c/0x1f70\n ext4_ext_map_blocks+0x146/0x2d40\n ext4_map_blocks+0x71e/0x1700\n ext4_do_writepages+0x1290/0x2800\n ext4_writepages+0x26d/0x4e0\n do_writepages+0x175/0x700\n[...]\n\nFreed by task 179:\n kfree+0xcb/0x240\n ext4_find_extent+0x7c0/0x1f70\n ext4_ext_insert_extent+0xa26/0x3330\n ext4_ext_map_blocks+0xe22/0x2d40\n ext4_map_blocks+0x71e/0x1700\n ext4_do_writepages+0x1290/0x2800\n ext4_writepages+0x26d/0x4e0\n do_writepages+0x175/0x700\n[...]\n==================================================================\n\nSo use *ppath to update the path to avoid the above problem.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/51db04892a993cace63415be99848970a0f15ef2","https://git.kernel.org/stable/c/5e811066c5ab709b070659197dccfb80ab650ddd","https://git.kernel.org/stable/c/8162ee5d94b8c0351be0a9321be134872a7654a1","https://git.kernel.org/stable/c/975ca06f3fd154c5f7742083e7b2574c57d1c0c3","https://git.kernel.org/stable/c/9df59009dfc6d9fc1bd9ddf6c5ab6e56d6ed887a"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:56:33.105311382+00:00"},"epss":{"cve":"CVE-2024-49883","score":0.00278,"percentile":0.20309,"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."]}