ghsa-hm4v-3pg5-6f5c
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: Fix NULL pointer dereference in object->file
At present, the object->file has the NULL pointer dereference problem in ondemand-mode. The root cause is that the allocated fd and object->file lifetime are inconsistent, and the user-space invocation to anon_fd uses object->file. Following is the process that triggers the issue:
[write fd] [umount]
cachefiles_ondemand_fd_write_iter fscache_cookie_state_machine cachefiles_withdraw_cookie if (!file) return -ENOBUFS cachefiles_clean_up_object cachefiles_unmark_inode_in_use fput(object->file) object->file = NULL // file NULL pointer dereference! __cachefiles_write(..., file, ...)
Fix this issue by add an additional reference count to the object->file before write/llseek, and decrement after it finished.
{ "affected": [], "aliases": [ "CVE-2024-56549" ], "database_specific": { "cwe_ids": [ "CWE-476" ], "github_reviewed": false, "github_reviewed_at": null, "nvd_published_at": "2024-12-27T14:15:34Z", "severity": "MODERATE" }, "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncachefiles: Fix NULL pointer dereference in object-\u003efile\n\nAt present, the object-\u003efile has the NULL pointer dereference problem in\nondemand-mode. The root cause is that the allocated fd and object-\u003efile\nlifetime are inconsistent, and the user-space invocation to anon_fd uses\nobject-\u003efile. Following is the process that triggers the issue:\n\n\t [write fd]\t\t\t\t[umount]\ncachefiles_ondemand_fd_write_iter\n\t\t\t\t fscache_cookie_state_machine\n\t\t\t\t\t cachefiles_withdraw_cookie\n if (!file) return -ENOBUFS\n\t\t\t\t\t cachefiles_clean_up_object\n\t\t\t\t\t cachefiles_unmark_inode_in_use\n\t\t\t\t\t fput(object-\u003efile)\n\t\t\t\t\t object-\u003efile = NULL\n // file NULL pointer dereference!\n __cachefiles_write(..., file, ...)\n\nFix this issue by add an additional reference count to the object-\u003efile\nbefore write/llseek, and decrement after it finished.", "id": "GHSA-hm4v-3pg5-6f5c", "modified": "2025-02-21T15:31:58Z", "published": "2024-12-27T15:31:53Z", "references": [ { "type": "ADVISORY", "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-56549" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/31ad74b20227ce6b40910ff78b1c604e42975cf1" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/785408bbafcfa24c9fc5b251f03fd0780ce182bd" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/9582c7664103c9043e80a78f5c382aa6bdd67418" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/d6bba3ece960129a553d4b16f1b00c884dc0993a" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/f98770440c9bc468e2fd878212ec9526dbe08293" } ], "schema_version": "1.4.0", "severity": [ { "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "type": "CVSS_V3" } ] }
Sightings
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