{"id":"CVE-2024-49884","title":"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: K…","summary":"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: K…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-416"],"vendor":"debian","product":"debian_linux","affected":["debian_linux = 11.0","linux_kernel >= 3.18, < 4.19.323","linux_kernel >= 4.20, < 5.4.290","linux_kernel >= 5.5, < 5.10.227","linux_kernel >= 5.11, < 5.15.168","linux_kernel >= 5.16, < 6.1.113","linux_kernel >= 6.2, < 6.6.55","linux_kernel >= 6.7, < 6.10.14","linux_kernel >= 6.11, < 6.11.3"],"patched":["linux_kernel 6.11.3"],"published":"2024-10-21","updated":"2026-10-15","sourceUpdated":"2026-10-15T01:18:59.270","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2024-49884","references":[{"url":"https://git.kernel.org/stable/c/393a46f60ea4f249dc9d496d4eb2d542f5e11ade","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/448100a29395b0c8b4c42967155849fe0fbe808f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5d949ea75bb529ea6342e83465938a3b0ac51238","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8fe117790b37c84c651e2bad9efc0e7fda73c0e3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/915ac3630488af0ca194dc63b86d99802b4f6e18","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a5401d4c3e2a3d25643c567d26e6de327774a2c9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c26ab35702f8cd0cdc78f96aa5856bfb77be798f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cafcc1bd62934547c76abf46c6d0d54f135006fe","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e52f933598b781d291b9297e39c463536da0e185","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-355557.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00268,"epssPercentile":0.1758,"ingestedAt":"2026-10-15T03:30:12.751Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2024-10-22T13:45:15.776351Z"},"slug":"CVE-2024-49884","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `debian_linux = 11.0`\n- `linux_kernel >= 3.18, < 4.19.323`\n- `linux_kernel >= 4.20, < 5.4.290`\n- `linux_kernel >= 5.5, < 5.10.227`\n- `linux_kernel >= 5.11, < 5.15.168`\n- `linux_kernel >= 5.16, < 6.1.113`\n- `linux_kernel >= 6.2, < 6.6.55`\n- `linux_kernel >= 6.7, < 6.10.14`\n- `linux_kernel >= 6.11, < 6.11.3`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.11.3`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}