{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-53171", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-11-19T17:17:25.006Z", "datePublished": "2024-12-27T13:49:16.423Z", "dateUpdated": "2026-08-05T11:44:19.813Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:44:19.813Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nubifs: authentication: Fix use-after-free in ubifs_tnc_end_commit\n\nAfter an insertion in TNC, the tree might split and cause a node to\nchange its `znode->parent`. A further deletion of other nodes in the\ntree (which also could free the nodes), the aforementioned node's\n`znode->cparent` could still point to a freed node. This\n`znode->cparent` may not be updated when getting nodes to commit in\n`ubifs_tnc_start_commit()`. This could then trigger a use-after-free\nwhen accessing the `znode->cparent` in `write_index()` in\n`ubifs_tnc_end_commit()`.\n\nThis can be triggered by running\n\n rm -f /etc/test-file.bin\n dd if=/dev/urandom of=/etc/test-file.bin bs=1M count=60 conv=fsync\n\nin a loop, and with `CONFIG_UBIFS_FS_AUTHENTICATION`. KASAN then\nreports:\n\n BUG: KASAN: use-after-free in ubifs_tnc_end_commit+0xa5c/0x1950\n Write of size 32 at addr ffffff800a3af86c by task ubifs_bgt0_20/153\n\n Call trace:\n dump_backtrace+0x0/0x340\n show_stack+0x18/0x24\n dump_stack_lvl+0x9c/0xbc\n print_address_description.constprop.0+0x74/0x2b0\n kasan_report+0x1d8/0x1f0\n kasan_check_range+0xf8/0x1a0\n memcpy+0x84/0xf4\n ubifs_tnc_end_commit+0xa5c/0x1950\n do_commit+0x4e0/0x1340\n ubifs_bg_thread+0x234/0x2e0\n kthread+0x36c/0x410\n ret_from_fork+0x10/0x20\n\n Allocated by task 401:\n kasan_save_stack+0x38/0x70\n __kasan_kmalloc+0x8c/0xd0\n __kmalloc+0x34c/0x5bc\n tnc_insert+0x140/0x16a4\n ubifs_tnc_add+0x370/0x52c\n ubifs_jnl_write_data+0x5d8/0x870\n do_writepage+0x36c/0x510\n ubifs_writepage+0x190/0x4dc\n __writepage+0x58/0x154\n write_cache_pages+0x394/0x830\n do_writepages+0x1f0/0x5b0\n filemap_fdatawrite_wbc+0x170/0x25c\n file_write_and_wait_range+0x140/0x190\n ubifs_fsync+0xe8/0x290\n vfs_fsync_range+0xc0/0x1e4\n do_fsync+0x40/0x90\n __arm64_sys_fsync+0x34/0x50\n invoke_syscall.constprop.0+0xa8/0x260\n do_el0_svc+0xc8/0x1f0\n el0_svc+0x34/0x70\n el0t_64_sync_handler+0x108/0x114\n el0t_64_sync+0x1a4/0x1a8\n\n Freed by task 403:\n kasan_save_stack+0x38/0x70\n kasan_set_track+0x28/0x40\n kasan_set_free_info+0x28/0x4c\n __kasan_slab_free+0xd4/0x13c\n kfree+0xc4/0x3a0\n tnc_delete+0x3f4/0xe40\n ubifs_tnc_remove_range+0x368/0x73c\n ubifs_tnc_remove_ino+0x29c/0x2e0\n ubifs_jnl_delete_inode+0x150/0x260\n ubifs_evict_inode+0x1d4/0x2e4\n evict+0x1c8/0x450\n iput+0x2a0/0x3c4\n do_unlinkat+0x2cc/0x490\n __arm64_sys_unlinkat+0x90/0x100\n invoke_syscall.constprop.0+0xa8/0x260\n do_el0_svc+0xc8/0x1f0\n el0_svc+0x34/0x70\n el0t_64_sync_handler+0x108/0x114\n el0t_64_sync+0x1a4/0x1a8\n\nThe offending `memcpy()` in `ubifs_copy_hash()` has a use-after-free\nwhen a node becomes root in TNC but still has a `cparent` to an already\nfreed node. More specifically, consider the following TNC:\n\n zroot\n /\n /\n zp1\n /\n /\n zn\n\nInserting a new node `zn_new` with a key smaller then `zn` will trigger\na split in `tnc_insert()` if `zp1` is full:\n\n zroot\n / \\\n / \\\n zp1 zp2\n / \\\n / \\\n zn_new zn\n\n`zn->parent` has now been moved to `zp2`, *but* `zn->cparent` still\npoints to `zp1`.\n\nNow, consider a removal of all the nodes _except_ `zn`. Just when\n`tnc_delete()` is about to delete `zroot` and `zp2`:\n\n zroot\n \\\n \\\n zp2\n \\\n \\\n zn\n\n`zroot` and `zp2` get freed and the tree collapses:\n\n zn\n\n`zn` now becomes the new `zroot`.\n\n`get_znodes_to_commit()` will now only find `zn`, the new `zroot`, and\n`write_index()` will check its `znode->cparent` that wrongly points to\nthe already freed `zp1`. `ubifs_copy_hash()` thus gets wrongly called\nwith `znode->cparent->zbranch[znode->iip].hash` that triggers the\nuse-after-free!\n\nFix this by explicitly setting `znode->cparent` to `NULL` in\n`get_znodes_to_commit()` for the root node. The search for the dirty\nnodes\n---truncated---" } ], "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 vulnerability is reached purely through local filesystem syscalls — write()/fsync() to grow the TNC, unlink() to free the old parent znode, and sync()/syncfs() to force the commit that performs the dangling write. There is no network-facing or remote path into UBIFS TNC commit.\nAC:L - The attacker fully controls every step: they choose the file creation/deletion sequence that produces the split-then-collapse tree shape (upstream reproduces it with a two-line dd/rm loop), and unprivileged syncfs() forces the commit on demand rather than waiting on the ubifs_bgt background thread, so this is a deterministic dangling-pointer dereference rather than a race against an uncontrolled party.\nPR:L - Only an ordinary unprivileged local account is required — creating, writing, unlinking files in any writable directory on the mounted UBIFS volume plus a sync()/syncfs() call, all with no capability. Mounting is root-only, but in the realistic deployment (authenticated UBIFS as the embedded rootfs) the filesystem is already mounted at boot.\nUI:N - The attacker performs the entire sequence themselves with their own file operations and their own syncfs() call; no victim action, no separate mount, and no interaction with another user's files is needed.\nS:U - The freed znode and the corrupted slab both live in kernel heap memory managed by the same kernel security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - The use-after-free corrupts a recycled generic-kmalloc object at an attacker-selectable offset, which can be leveraged to smash length, index, or pointer fields of sprayed structures (msg_msg, pipe buffers, keyring payloads) and turn them into an out-of-bounds kernel memory read, disclosing arbitrary kernel data.\nI:H - This is a 32-byte use-after-free WRITE (`memcpy(cparent->zbranch[ciip].hash, hash, 32)`, confirmed by KASAN's \"Write of size 32\") into a freed, spray-reallocatable slab object at one of several attacker-selectable offsets, giving a heap corruption primitive suitable for control-flow hijacking and local privilege escalation.\nA:H - The use-after-free write corrupts arbitrary recycled kernel heap objects and reliably produces oopses or panics, and it fires from the ubifs_bgt kthread or the commit path where failure marks the filesystem COMMIT_BROKEN/read-only, rendering the device unusable." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ubifs/tnc_commit.c" ], "versions": [ { "version": "16a26b20d2afd0cf063816725b45b12e78d5bb31", "lessThan": "daac4aa1825de0dbc1a6eede2fa7f9fc53f14223", "status": "affected", "versionType": "git" }, { "version": "16a26b20d2afd0cf063816725b45b12e78d5bb31", "lessThan": "8d8b3f5f4cbfbf6cb0ea4a4d5dc296872b4151eb", "status": "affected", "versionType": "git" }, { "version": "16a26b20d2afd0cf063816725b45b12e78d5bb31", "lessThan": "4d9807048b851d7a58d5bd089c16254af896e4df", "status": "affected", "versionType": "git" }, { "version": "16a26b20d2afd0cf063816725b45b12e78d5bb31", "lessThan": "74981f7577d183acad1cd58f74c10d263711a215", "status": "affected", "versionType": "git" }, { "version": "16a26b20d2afd0cf063816725b45b12e78d5bb31", "lessThan": "01d3a2293d7e4edfff96618c15727db7e51f11b6", "status": "affected", "versionType": "git" }, { "version": "16a26b20d2afd0cf063816725b45b12e78d5bb31", "lessThan": "398a91599d263e41c5f95a2fd4ebdb6280b5c6c3", "status": "affected", "versionType": "git" }, { "version": "16a26b20d2afd0cf063816725b45b12e78d5bb31", "lessThan": "2497479aecebe869d23a0064e0fd1a03e34f0e2a", "status": "affected", "versionType": "git" }, { "version": "16a26b20d2afd0cf063816725b45b12e78d5bb31", "lessThan": "4617fb8fc15effe8eda4dd898d4e33eb537a7140", "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/ubifs/tnc_commit.c" ], "versions": [ { "version": "4.20", "status": "affected" }, { "version": "0", "lessThan": "4.20", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.287", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.231", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.174", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.120", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.64", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.11.11", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.2", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13", "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": "4.20", "versionEndExcluding": "5.4.287" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "5.10.231" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "5.15.174" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.1.120" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.6.64" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.11.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.12.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.13" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/daac4aa1825de0dbc1a6eede2fa7f9fc53f14223" }, { "url": "https://git.kernel.org/stable/c/8d8b3f5f4cbfbf6cb0ea4a4d5dc296872b4151eb" }, { "url": "https://git.kernel.org/stable/c/4d9807048b851d7a58d5bd089c16254af896e4df" }, { "url": "https://git.kernel.org/stable/c/74981f7577d183acad1cd58f74c10d263711a215" }, { "url": "https://git.kernel.org/stable/c/01d3a2293d7e4edfff96618c15727db7e51f11b6" }, { "url": "https://git.kernel.org/stable/c/398a91599d263e41c5f95a2fd4ebdb6280b5c6c3" }, { "url": "https://git.kernel.org/stable/c/2497479aecebe869d23a0064e0fd1a03e34f0e2a" }, { "url": "https://git.kernel.org/stable/c/4617fb8fc15effe8eda4dd898d4e33eb537a7140" } ], "title": "ubifs: authentication: Fix use-after-free in ubifs_tnc_end_commit", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2024-53171", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2025-02-11T15:43:44.944550Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-02-11T15:45:27.208Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T20:47:01.188Z" } } ] } }