{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "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."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "fs/ext4/extents.c"
               ],
               "versions": [
                  {
                     "version": "dfe5080939ea",
                     "lessThan": "e52f933598b7",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "dfe5080939ea",
                     "lessThan": "cafcc1bd6293",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "dfe5080939ea",
                     "lessThan": "a5401d4c3e2a",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "dfe5080939ea",
                     "lessThan": "8fe117790b37",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "dfe5080939ea",
                     "lessThan": "5d949ea75bb5",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "dfe5080939ea",
                     "lessThan": "915ac3630488",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "dfe5080939ea",
                     "lessThan": "c26ab35702f8",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "fs/ext4/extents.c"
               ],
               "versions": [
                  {
                     "version": "3.18",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "3.18",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.10.227",
                     "lessThanOrEqual": "5.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.15.168",
                     "lessThanOrEqual": "5.15.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.1.113",
                     "lessThanOrEqual": "6.1.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.6.55",
                     "lessThanOrEqual": "6.6.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.10.14",
                     "lessThanOrEqual": "6.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.11.3",
                     "lessThanOrEqual": "6.11.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.12-rc1",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/e52f933598b781d291b9297e39c463536da0e185"
            },
            {
               "url": "https://git.kernel.org/stable/c/cafcc1bd62934547c76abf46c6d0d54f135006fe"
            },
            {
               "url": "https://git.kernel.org/stable/c/a5401d4c3e2a3d25643c567d26e6de327774a2c9"
            },
            {
               "url": "https://git.kernel.org/stable/c/8fe117790b37c84c651e2bad9efc0e7fda73c0e3"
            },
            {
               "url": "https://git.kernel.org/stable/c/5d949ea75bb529ea6342e83465938a3b0ac51238"
            },
            {
               "url": "https://git.kernel.org/stable/c/915ac3630488af0ca194dc63b86d99802b4f6e18"
            },
            {
               "url": "https://git.kernel.org/stable/c/c26ab35702f8cd0cdc78f96aa5856bfb77be798f"
            }
         ],
         "title": "ext4: fix slab-use-after-free in ext4_split_extent_at()",
         "x_generator": {
            "engine": "bippy-c9c4e1df01b2"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2024-49884",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}