{"id":"AZL-51544","summary":"CVE-2024-49881 affecting package kernel for versions less than 5.15.173.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: update orig_path in ext4_find_extent()\n\nIn ext4_find_extent(), if the path is not big enough, we free it and set\n*orig_path to NULL. But after reallocating and successfully initializing\nthe path, we don't update *orig_path, in which case the caller gets a\nvalid path but a NULL ppath, and this may cause a NULL pointer dereference\nor a path memory leak. For example:\n\next4_split_extent\n  path = *ppath = 2000\n  ext4_find_extent\n    if (depth \u003e path[0].p_maxdepth)\n      kfree(path = 2000);\n      *orig_path = path = NULL;\n      path = kcalloc() = 3000\n  ext4_split_extent_at(*ppath = NULL)\n    path = *ppath;\n    ex = path[depth].p_ext;\n    // NULL pointer dereference!\n\n==================================================================\nBUG: kernel NULL pointer dereference, address: 0000000000000010\nCPU: 6 UID: 0 PID: 576 Comm: fsstress Not tainted 6.11.0-rc2-dirty #847\nRIP: 0010:ext4_split_extent_at+0x6d/0x560\nCall Trace:\n \u003cTASK\u003e\n ext4_split_extent.isra.0+0xcb/0x1b0\n ext4_ext_convert_to_initialized+0x168/0x6c0\n ext4_ext_handle_unwritten_extents+0x325/0x4d0\n ext4_ext_map_blocks+0x520/0xdb0\n ext4_map_blocks+0x2b0/0x690\n ext4_iomap_begin+0x20e/0x2c0\n[...]\n==================================================================\n\nTherefore, *orig_path is updated when the extent lookup succeeds, so that\nthe caller can safely use path or *ppath.","modified":"2026-04-01T05:17:45.607479Z","published":"2024-10-21T18:15:10Z","upstream":["CVE-2024-49881"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-49881"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.173.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-51544.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}