{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2024-49882", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2024-49882", "idYear": 2024, "status": "PUBLISHED", "publishedAt": "2024-10-21T18:01:20.144Z", "updatedAt": "2026-08-05T11:40:20.352Z", "importedAt": "2026-10-24T01:57:16.009Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "ext4: fix double brelse() the buffer of the extents path", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix double brelse() the buffer of the extents path\n\nIn ext4_ext_try_to_merge_up(), set path[1].p_bh to NULL after it has been\nreleased, otherwise it may be released twice. An example of what triggers\nthis is as follows:\n\n split2 map split1\n|--------|-------|--------|\n\next4_ext_map_blocks\n ext4_ext_handle_unwritten_extents\n ext4_split_convert_extents\n // path->p_depth == 0\n ext4_split_extent\n // 1. do split1\n ext4_split_extent_at\n |ext4_ext_insert_extent\n | ext4_ext_create_new_leaf\n | ext4_ext_grow_indepth\n | le16_add_cpu(&neh->eh_depth, 1)\n | ext4_find_extent\n | // return -ENOMEM\n |// get error and try zeroout\n |path = ext4_find_extent\n | path->p_depth = 1\n |ext4_ext_try_to_merge\n | ext4_ext_try_to_merge_up\n | path->p_depth = 0\n | brelse(path[1].p_bh) ---> not set to NULL here\n |// zeroout success\n // 2. update path\n ext4_find_extent\n // 3. do split2\n ext4_split_extent_at\n ext4_ext_insert_extent\n ext4_ext_create_new_leaf\n ext4_ext_grow_indepth\n le16_add_cpu(&neh->eh_depth, 1)\n ext4_find_extent\n path[0].p_bh = NULL;\n path->p_depth = 1\n read_extent_tree_block ---> return err\n // path[1].p_bh is still the old value\n ext4_free_ext_path\n ext4_ext_drop_refs\n // path->p_depth == 1\n brelse(path[1].p_bh) ---> brelse a buffer twice\n\nFinally got the following WARRNING when removing the buffer from lru:\n\n============================================\nVFS: brelse: Trying to free free buffer\nWARNING: CPU: 2 PID: 72 at fs/buffer.c:1241 __brelse+0x58/0x90\nCPU: 2 PID: 72 Comm: kworker/u19:1 Not tainted 6.9.0-dirty #716\nRIP: 0010:__brelse+0x58/0x90\nCall Trace:\n \n __find_get_block+0x6e7/0x810\n bdev_getblk+0x2b/0x480\n __ext4_get_inode_loc+0x48a/0x1240\n ext4_get_inode_loc+0xb2/0x150\n ext4_reserve_inode_write+0xb7/0x230\n __ext4_mark_inode_dirty+0x144/0x6a0\n ext4_ext_insert_extent+0x9c8/0x3230\n ext4_ext_map_blocks+0xf45/0x2dc0\n ext4_map_blocks+0x724/0x1700\n ext4_do_writepages+0x12d6/0x2a70\n[...]\n============================================", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "ecb94f5fdf4b72547fca022421a9dca1672bddd4", "status": "affected", "versionType": "git", "lessThan": "d4574bda63906bf69660e001470bfe1a0ac524ae" }, { "version": "ecb94f5fdf4b72547fca022421a9dca1672bddd4", "status": "affected", "versionType": "git", "lessThan": "f9fd47c9d9548f9e47fa60098eab99dde175401d" }, { "version": "ecb94f5fdf4b72547fca022421a9dca1672bddd4", "status": "affected", "versionType": "git", "lessThan": "b6c29c8f3d7cb67b505f3b2f6c242d52298d1f2e" }, { "version": "ecb94f5fdf4b72547fca022421a9dca1672bddd4", "status": "affected", "versionType": "git", "lessThan": "32bbb59e3f18facd7201bef110010bf35819b8c3" }, { "version": "ecb94f5fdf4b72547fca022421a9dca1672bddd4", "status": "affected", "versionType": "git", "lessThan": "78bbc3d15b6f443acb26e94418c445bac940d414" }, { "version": "ecb94f5fdf4b72547fca022421a9dca1672bddd4", "status": "affected", "versionType": "git", "lessThan": "68a69cf60660c73990c1875f94a5551600b04775" }, { "version": "ecb94f5fdf4b72547fca022421a9dca1672bddd4", "status": "affected", "versionType": "git", "lessThan": "7633407ca4ab8be2916ab214eb44ccebc6a50e1a" }, { "version": "ecb94f5fdf4b72547fca022421a9dca1672bddd4", "status": "affected", "versionType": "git", "lessThan": "230ee0535d01478bad9a3037292043f39b9be10b" }, { "version": "ecb94f5fdf4b72547fca022421a9dca1672bddd4", "status": "affected", "versionType": "git", "lessThan": "dcaa6c31134c0f515600111c38ed7750003e1b9c" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "3.7", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "3.7" }, { "version": "4.19.323", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.19.*" }, { "version": "5.4.285", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.4.*" }, { "version": "5.10.227", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.168", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.113", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.55", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.10.14", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.10.*" }, { "version": "6.11.3", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.11.*" }, { "version": "6.12", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }