{"id":"CVE-2024-44939","state":"PUBLISHED","title":"jfs: fix null ptr deref in dtInsertEntry","description":"In the Linux kernel, the following vulnerability has been resolved:\n\njfs: fix null ptr deref in dtInsertEntry\n\n[syzbot reported]\ngeneral protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI\nKASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]\nCPU: 0 PID: 5061 Comm: syz-executor404 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024\nRIP: 0010:dtInsertEntry+0xd0c/0x1780 fs/jfs/jfs_dtree.c:3713\n...\n[Analyze]\nIn dtInsertEntry(), when the pointer h has the same value as p, after writing\nname in UniStrncpy_to_le(), p->header.flag will be cleared. This will cause the\npreviously true judgment \"p->header.flag & BT-LEAF\" to change to no after writing\nthe name operation, this leads to entering an incorrect branch and accessing the\nuninitialized object ih when judging this condition for the second time.\n\n[Fix]\nAfter got the page, check freelist first, if freelist == 0 then exit dtInsert()\nand return -EINVAL.","publishedAt":"2024-08-26T11:20:44.129Z","updatedAt":"2026-08-05T11:37:08.416Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"f98bf80b20f4a930589cda48a35f751a64fe0dc2","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"53023ab11836ac56fd75f7a71ec1356e50920fa9","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6ea10dbb1e6c58384136e9adfd75f81951e423f6","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"9c2ac38530d1a3ee558834dfa16c85a40fd0e702","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"ce6dede912f064a855acf6f04a04cbb2c25b8c8c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/jfs/jfs_dtree.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.15.189","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.107","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.47","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.6","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/jfs/jfs_dtree.c"]}],"references":["https://git.kernel.org/stable/c/f98bf80b20f4a930589cda48a35f751a64fe0dc2","https://git.kernel.org/stable/c/53023ab11836ac56fd75f7a71ec1356e50920fa9","https://git.kernel.org/stable/c/6ea10dbb1e6c58384136e9adfd75f81951e423f6","https://git.kernel.org/stable/c/9c2ac38530d1a3ee558834dfa16c85a40fd0e702","https://git.kernel.org/stable/c/ce6dede912f064a855acf6f04a04cbb2c25b8c8c","https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:07:47.831Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/44xxx/CVE-2024-44939.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-44939","state":"PUBLISHED","datePublished":"2024-08-26T11:20:44.129Z","dateUpdated":"2026-08-05T11:37:08.416Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-08-21T05:34:56.664Z"},"containers":{"cna":{"title":"jfs: fix null ptr deref in dtInsertEntry","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\njfs: fix null ptr deref in dtInsertEntry\n\n[syzbot reported]\ngeneral protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI\nKASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]\nCPU: 0 PID: 5061 Comm: syz-executor404 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024\nRIP: 0010:dtInsertEntry+0xd0c/0x1780 fs/jfs/jfs_dtree.c:3713\n...\n[Analyze]\nIn dtInsertEntry(), when the pointer h has the same value as p, after writing\nname in UniStrncpy_to_le(), p->header.flag will be cleared. This will cause the\npreviously true judgment \"p->header.flag & BT-LEAF\" to change to no after writing\nthe name operation, this leads to entering an incorrect branch and accessing the\nuninitialized object ih when judging this condition for the second time.\n\n[Fix]\nAfter got the page, check freelist first, if freelist == 0 then exit dtInsert()\nand return -EINVAL."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"f98bf80b20f4a930589cda48a35f751a64fe0dc2","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"53023ab11836ac56fd75f7a71ec1356e50920fa9","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6ea10dbb1e6c58384136e9adfd75f81951e423f6","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"9c2ac38530d1a3ee558834dfa16c85a40fd0e702","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"ce6dede912f064a855acf6f04a04cbb2c25b8c8c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/jfs/jfs_dtree.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.15.189","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.107","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.47","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.6","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/jfs/jfs_dtree.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f98bf80b20f4a930589cda48a35f751a64fe0dc2"},{"url":"https://git.kernel.org/stable/c/53023ab11836ac56fd75f7a71ec1356e50920fa9"},{"url":"https://git.kernel.org/stable/c/6ea10dbb1e6c58384136e9adfd75f81951e423f6"},{"url":"https://git.kernel.org/stable/c/9c2ac38530d1a3ee558834dfa16c85a40fd0e702"},{"url":"https://git.kernel.org/stable/c/ce6dede912f064a855acf6f04a04cbb2c25b8c8c"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable path is reached only through local directory-modifying syscalls (creat/mkdir/link/symlink/mknod/rename) on a mounted JFS volume; there is no network-facing consumer of jfs_dtree.c.\nAC:L - Fully deterministic — a directory page crafted with header.freelist==0 and freecnt>=1 passes the era's DT_GETPAGE sanity checks, and a single file creation with an attacker-chosen name reliably reaches the aliased slot[0] write; no race and no memory-layout dependency.\nPR:L - Any unprivileged local user with write access to a directory on the mounted crafted volume triggers it via an ordinary creat()/mkdir(); dtInsert() performs no capability or credential check on the path from jfs_create()/jfs_mkdir().\nUI:N - Once the untrusted JFS volume is mounted (kiosk/shared removable media automount, admin-mounted image, or a container/VM handed a JFS disk), the attacker triggers the bug entirely on their own with a single syscall — no victim action at attack time.\nS:U - The corruption and crash are confined to the kernel's own memory and the JFS metadata it manages; no VM, IOMMU, or other security-authority boundary is crossed.\nC:H - The overwritten header leaves stblindex/maxslot/nextindex and the self PXD attacker-controlled, so subsequent p->slot[stbl[i]] and p->slot[next] accesses in dtSearch/jfs_readdir read out of bounds and return adjacent kernel heap bytes — and arbitrary disk blocks via the poisoned self PXD fed to add_index() — to userspace as dirent names and inode numbers.\nI:H - Attacker-chosen bytes (inode number, UTF-16LE filename, dir index) are written over the dtree page header, which is already dirtied and linelocked so the corruption is journaled to disk, and the resulting attacker-controlled s8 slot indices yield out-of-bounds heap writes on this and subsequent directory operations.\nA:H - The reported and readily reproduced outcome is a general protection fault writing to NULL+8 in dtInsertEntry(), an immediate kernel oops; the corrupted directory page also causes further faults on later access."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T11:37:08.416Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.15.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.1.107"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.6.47"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.10.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.11"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-44939","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T15:27:35.487089Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-12T17:33:06.654Z"}},{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T22:13:44.114Z"}}]}}}