| { |
| "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-out-of-bounds in ext4_mb_find_good_group_avg_frag_lists()\n\nWe can trigger a slab-out-of-bounds with the following commands:\n\n mkfs.ext4 -F /dev/$disk 10G\n mount /dev/$disk /tmp/test\n echo 2147483647 > /sys/fs/ext4/$disk/mb_group_prealloc\n echo test > /tmp/test/file && sync\n\n==================================================================\nBUG: KASAN: slab-out-of-bounds in ext4_mb_find_good_group_avg_frag_lists+0x8a/0x200 [ext4]\nRead of size 8 at addr ffff888121b9d0f0 by task kworker/u2:0/11\nCPU: 0 PID: 11 Comm: kworker/u2:0 Tainted: GL 6.7.0-next-20240118 #521\nCall Trace:\n dump_stack_lvl+0x2c/0x50\n kasan_report+0xb6/0xf0\n ext4_mb_find_good_group_avg_frag_lists+0x8a/0x200 [ext4]\n ext4_mb_regular_allocator+0x19e9/0x2370 [ext4]\n ext4_mb_new_blocks+0x88a/0x1370 [ext4]\n ext4_ext_map_blocks+0x14f7/0x2390 [ext4]\n ext4_map_blocks+0x569/0xea0 [ext4]\n ext4_do_writepages+0x10f6/0x1bc0 [ext4]\n[...]\n==================================================================\n\nThe flow of issue triggering is as follows:\n\n// Set s_mb_group_prealloc to 2147483647 via sysfs\next4_mb_new_blocks\n ext4_mb_normalize_request\n ext4_mb_normalize_group_request\n ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc\n ext4_mb_regular_allocator\n ext4_mb_choose_next_group\n ext4_mb_choose_next_group_best_avail\n mb_avg_fragment_size_order\n order = fls(len) - 2 = 29\n ext4_mb_find_good_group_avg_frag_lists\n frag_list = &sbi->s_mb_avg_fragment_size[order]\n if (list_empty(frag_list)) // Trigger SOOB!\n\nAt 4k block size, the length of the s_mb_avg_fragment_size list is 14,\nbut an oversized s_mb_group_prealloc is set, causing slab-out-of-bounds\nto be triggered by an attempt to access an element at index 29.\n\nAdd a new attr_id attr_clusters_in_group with values in the range\n[0, sbi->s_clusters_per_group] and declare mb_group_prealloc as\nthat type to fix the issue. In addition avoid returning an order\nfrom mb_avg_fragment_size_order() greater than MB_NUM_ORDERS(sb)\nand reduce some useless loops." |
| } |
| ], |
| "affected": [ |
| { |
| "product": "Linux", |
| "vendor": "Linux", |
| "defaultStatus": "unaffected", |
| "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", |
| "programFiles": [ |
| "fs/ext4/mballoc.c", |
| "fs/ext4/sysfs.c" |
| ], |
| "versions": [ |
| { |
| "version": "7e170922f06bf46effa7c57f6035fc463d6edc7e", |
| "lessThan": "677ff4589f1501578fa903a25bb14831d0607992", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "7e170922f06bf46effa7c57f6035fc463d6edc7e", |
| "lessThan": "b829687ae1229224262bcabf49accfa2dbf8db06", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "7e170922f06bf46effa7c57f6035fc463d6edc7e", |
| "lessThan": "13df4d44a3aaabe61cd01d277b6ee23ead2a5206", |
| "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/mballoc.c", |
| "fs/ext4/sysfs.c" |
| ], |
| "versions": [ |
| { |
| "version": "6.5", |
| "status": "affected" |
| }, |
| { |
| "version": "0", |
| "lessThan": "6.5", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "6.6.36", |
| "lessThanOrEqual": "6.6.*", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "6.9.7", |
| "lessThanOrEqual": "6.9.*", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "6.10", |
| "lessThanOrEqual": "*", |
| "status": "unaffected", |
| "versionType": "original_commit_for_fix" |
| } |
| ] |
| } |
| ], |
| "cpeApplicability": [ |
| { |
| "nodes": [ |
| { |
| "operator": "OR", |
| "negate": false, |
| "cpeMatch": [ |
| { |
| "vulnerable": true, |
| "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", |
| "versionStartIncluding": "6.5", |
| "versionEndExcluding": "6.6.36" |
| }, |
| { |
| "vulnerable": true, |
| "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", |
| "versionStartIncluding": "6.5", |
| "versionEndExcluding": "6.9.7" |
| }, |
| { |
| "vulnerable": true, |
| "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", |
| "versionStartIncluding": "6.5", |
| "versionEndExcluding": "6.10" |
| } |
| ] |
| } |
| ] |
| } |
| ], |
| "references": [ |
| { |
| "url": "https://git.kernel.org/stable/c/677ff4589f1501578fa903a25bb14831d0607992" |
| }, |
| { |
| "url": "https://git.kernel.org/stable/c/b829687ae1229224262bcabf49accfa2dbf8db06" |
| }, |
| { |
| "url": "https://git.kernel.org/stable/c/13df4d44a3aaabe61cd01d277b6ee23ead2a5206" |
| } |
| ], |
| "title": "ext4: fix slab-out-of-bounds in ext4_mb_find_good_group_avg_frag_lists()", |
| "x_generator": { |
| "engine": "bippy-1.2.0" |
| } |
| } |
| }, |
| "cveMetadata": { |
| "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038", |
| "cveID": "CVE-2024-40955", |
| "requesterUserId": "gregkh@kernel.org", |
| "serial": "1", |
| "state": "PUBLISHED" |
| }, |
| "dataType": "CVE_RECORD", |
| "dataVersion": "5.0" |
| } |
