{"id":"CVE-2024-49884","revision":"f225dfd8faa4474eb0e7b935b479974a","records":[{"revision":"f225dfd8faa4474eb0e7b935b479974a","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2024-49884","aliases":[],"title":"ext4: fix slab-use-after-free in ext4_split_extent_at()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix slab-use-after-free in ext4_split_extent_at()\n\nWe hit the following use-after-free:\n\n==================================================================\nBUG: KASAN: slab-use-after-free in ext4_split_extent_at+0xba8/0xcc0\nRead of size 2 at addr ffff88810548ed08 by task kworker/u20:0/40\nCPU: 0 PID: 40 Comm: kworker/u20:0 Not tainted 6.9.0-dirty #724\nCall Trace:\n <TASK>\n kasan_report+0x93/0xc0\n ext4_split_extent_at+0xba8/0xcc0\n ext4_split_extent.isra.0+0x18f/0x500\n ext4_split_convert_extents+0x275/0x750\n ext4_ext_handle_unwritten_extents+0x73e/0x1580\n ext4_ext_map_blocks+0xe20/0x2dc0\n ext4_map_blocks+0x724/0x1700\n ext4_do_writepages+0x12d6/0x2a70\n[...]\n\nAllocated by task 40:\n __kmalloc_noprof+0x1ac/0x480\n ext4_find_extent+0xf3b/0x1e70\n ext4_ext_map_blocks+0x188/0x2dc0\n ext4_map_blocks+0x724/0x1700\n ext4_do_writepages+0x12d6/0x2a70\n[...]\n\nFreed by task 40:\n kfree+0xf1/0x2b0\n ext4_find_extent+0xa71/0x1e70\n ext4_ext_insert_extent+0xa22/0x3260\n ext4_split_extent_at+0x3ef/0xcc0\n ext4_split_extent.isra.0+0x18f/0x500\n ext4_split_convert_extents+0x275/0x750\n ext4_ext_handle_unwritten_extents+0x73e/0x1580\n ext4_ext_map_blocks+0xe20/0x2dc0\n ext4_map_blocks+0x724/0x1700\n ext4_do_writepages+0x12d6/0x2a70\n[...]\n==================================================================\n\nThe flow of issue triggering is as follows:\n\next4_split_extent_at\n  path = *ppath\n  ext4_ext_insert_extent(ppath)\n    ext4_ext_create_new_leaf(ppath)\n      ext4_find_extent(orig_path)\n        path = *orig_path\n        read_extent_tree_block\n          // return -ENOMEM or -EIO\n        ext4_free_ext_path(path)\n          kfree(path)\n        *orig_path = NULL\n  a. If err is -ENOMEM:\n  ext4_ext_dirty(path + path->p_depth)\n  // path use-after-free !!!\n  b. If err is -EIO and we have EXT_DEBUG defined:\n  ext4_ext_show_leaf(path)\n    eh = path[depth].p_hdr\n    // path also use-after-free !!!\n\nSo when trying to zeroout or fix the extent length, call ext4_find_extent()\nto update the path.\n\nIn addition we use *ppath directly as an ext4_ext_show_leaf() input to\navoid possible use-after-free when EXT_DEBUG is defined, and to avoid\nunnecessary path updates.","state":0,"publishedAt":"2024-10-21T18:01:21.517+00:00","modifiedAt":"2026-10-15T00:53:34.802+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/ext4/extents.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"dfe5080939ea4686b3414b5d970a9b26733c57a4\",\n                            \"lessThan\": \"393a46f60ea4f249dc9d496d4eb2d542f5e11ade\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"dfe5080939ea4686b3414b5d970a9b26733c57a4\",\n                            \"lessThan\": \"448100a29395b0c8b4c42967155849fe0fbe808f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"dfe5080939ea4686b3414b5d970a9b26733c57a4\",\n                            \"lessThan\": \"e52f933598b781d291b9297e39c463536da0e185\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"dfe5080939ea4686b3414b5d970a9b26733c57a4\",\n                            \"lessThan\": \"cafcc1bd62934547c76abf46c6d0d54f135006fe\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"dfe5080939ea4686b3414b5d970a9b26733c57a4\",\n                            \"lessThan\": \"a5401d4c3e2a3d25643c567d26e6de327774a2c9\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"dfe5080939ea4686b3414b5d970a9b26733c57a4\",\n                            \"lessThan\": \"8fe117790b37c84c651e2bad9efc0e7fda73c0e3\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"dfe5080939ea4686b3414b5d970a9b26733c57a4\",\n                            \"lessThan\": \"5d949ea75bb529ea6342e83465938a3b0ac51238\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"dfe5080939ea4686b3414b5d970a9b26733c57a4\",\n                            \"lessThan\": \"915ac3630488af0ca194dc63b86d99802b4f6e18\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"dfe5080939ea4686b3414b5d970a9b26733c57a4\",\n                            \"lessThan\": \"c26ab35702f8cd0cdc78f96aa5856bfb77be798f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/ext4/extents.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3.18\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"3.18\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"4.19.323\",\n                            \"lessThanOrEqual\": \"4.19.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.4.290\",\n                            \"lessThanOrEqual\": \"5.4.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.227\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.168\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.113\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.55\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.10.14\",\n                            \"lessThanOrEqual\": \"6.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.11.3\",\n                            \"lessThanOrEqual\": \"6.11.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 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,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/393a46f60ea4f249dc9d496d4eb2d542f5e11ade","https://git.kernel.org/stable/c/448100a29395b0c8b4c42967155849fe0fbe808f","https://git.kernel.org/stable/c/e52f933598b781d291b9297e39c463536da0e185","https://git.kernel.org/stable/c/cafcc1bd62934547c76abf46c6d0d54f135006fe","https://git.kernel.org/stable/c/a5401d4c3e2a3d25643c567d26e6de327774a2c9","https://git.kernel.org/stable/c/8fe117790b37c84c651e2bad9efc0e7fda73c0e3","https://git.kernel.org/stable/c/5d949ea75bb529ea6342e83465938a3b0ac51238","https://git.kernel.org/stable/c/915ac3630488af0ca194dc63b86d99802b4f6e18","https://git.kernel.org/stable/c/c26ab35702f8cd0cdc78f96aa5856bfb77be798f"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2024-49884","license":"CVE Program Terms of Use","key":"cve-program:CVE-2024-49884","identifiers":["CVE-2024-49884"]},"retained":false,"historicalAffected":[]}],"coverage":[]}