{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-97583", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-24T16:01:01.156Z", "datePublished": "2026-09-25T10:22:03.666Z", "dateUpdated": "2026-10-19T09:09:46.971Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:09:46.971Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nafs: Clear stale peer app data after address list changes\n\nafs_fs_probe_fileserver() fetches the current endpoint state under\nserver->fs_lock, but leaves old_alist as NULL. Consequently,\nafs_set_peer_appdata() treats every address list replacement as initial\nsetup and only binds the new peers; it never unbinds peers removed from\nthe old list.\n\nAn address refresh can therefore proceed as follows. CPU 0 replaces\nserver S's list and drops Pold without clearing Pold->app_data. The\nserver destroyer then clears only S's current peers and lets S reach its\nRCU callback. After the callback frees S, CPU 1 handles a callback\nthrough an RxRPC connection that still pins Pold, reads Pold->app_data,\nand calls afs_use_server() on the freed object.\n\nKASAN reported:\n\n BUG: KASAN: slab-use-after-free in afs_find_server+0x3c/0xa0\n Read of size 4 at addr ffff8881013e1af0 by task krxrpcio/7001/74\n Call Trace:\n afs_find_server+0x3c/0xa0\n afs_rx_new_call+0x15c/0x390\n rxrpc_new_incoming_call+0x97c/0x1730\n rxrpc_input_packet.constprop.0+0xd03/0xec0\n rxrpc_io_thread+0x967/0x1640\n Allocated by task 93:\n afs_lookup_server+0x1a7/0x14c0\n afs_alloc_server_list+0x43f/0xb60\n afs_create_volume+0x923/0x1490\n afs_get_tree+0x1c6/0x10a0\n Freed by task 0:\n kfree+0x131/0x3c0\n rcu_core+0x50a/0x1850\n Last potentially related work creation:\n __call_rcu_common.constprop.0+0x71/0xa10\n afs_put_server+0x213/0x2b0\n\nPreserve old->addresses for the peer app-data update so that removed\npeers are cleared before the endpoint state is replaced. Also advance\nboth cursors when the old and new lists share a peer; activating the\nold/new comparison without this would otherwise loop forever on the\nshared entry." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - A remote cell operator supplies the changed fileserver address list in the VL address-lookup reply (afs_vl_lookup_addrs -> afs_fs_probe_fileserver). A later incoming RxRPC call over UDP from a dropped peer reaches afs_rx_new_call -> afs_find_server, which dereferences the freed server through the stale peer app_data.\nAC:H - Triggering needs a specific order of events: the client refreshes the server's address list and gets a new version, then the server record goes unused and is freed by afs_server_destroyer after the GC delay, while an RxRPC connection still holds the old peer. Only then does a new incoming call hit it. The refresh and teardown timing follow the client's own activity, not the attacker's.\nPR:N - The VL reply and the incoming cache-manager call that reaches afs_rx_new_call/afs_find_server are handled before any server identity check. The attacker needs no account on the victim host.\nUI:R - The victim must have mounted, or be actively using, a volume from the attacker's AFS cell so that afs_lookup_server and afs_update_server_record run against the attacker's VL server. AFS mounts are not user-namespace mountable.\nS:U - The use-after-free happens in the kernel AFS client's afs_server object and stays within the kernel's own security authority. No VM, sandbox or IOMMU boundary is crossed.\nC:H - afs_use_server() works on a freed kmalloc'd afs_server reached through the stale peer app_data. If that slab is reclaimed, fields the attacker controls are read as server state, including pointers, which can leak kernel memory.\nI:H - afs_use_server() increments the active counter, and the call path then takes references and queues work on the freed afs_server. Writing into a reallocated object gives a memory-corruption primitive that could be used to hijack control flow.\nA:H - A slab use-after-free in the krxrpcio I/O thread (see the KASAN report in the commit) can oops or panic the kernel and bring down all AFS and RxRPC service on the host." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/afs/addr_list.c", "fs/afs/fs_probe.c" ], "versions": [ { "version": "39ba6af83a7f9dee3e6a7916f41a48bcbda54eba", "lessThan": "3afb988fd0411707bdafb9b321086fff0da28aae", "status": "affected", "versionType": "git" }, { "version": "40e8b52fe8c8ab6920ea5f59c5469b6918cce624", "lessThan": "c7f77a11a1e719192c7262aad38a3919aec62c21", "status": "affected", "versionType": "git" }, { "version": "40e8b52fe8c8ab6920ea5f59c5469b6918cce624", "lessThan": "7f7f5589d048821dea316cbac9b37d27eaf7530e", "status": "affected", "versionType": "git" }, { "version": "40e8b52fe8c8ab6920ea5f59c5469b6918cce624", "lessThan": "ba0623fc19a424f4745394c499f9f28a8d88d397", "status": "affected", "versionType": "git" }, { "version": "6.12.101", "lessThan": "6.12.111", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/afs/addr_list.c", "fs/afs/fs_probe.c" ], "versions": [ { "version": "6.15", "status": "affected" }, { "version": "0", "lessThan": "6.15", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.53", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.7", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "6.12.101", "versionEndExcluding": "6.12.111" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "6.18.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.2.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3afb988fd0411707bdafb9b321086fff0da28aae" }, { "url": "https://git.kernel.org/stable/c/c7f77a11a1e719192c7262aad38a3919aec62c21" }, { "url": "https://git.kernel.org/stable/c/7f7f5589d048821dea316cbac9b37d27eaf7530e" }, { "url": "https://git.kernel.org/stable/c/ba0623fc19a424f4745394c499f9f28a8d88d397" } ], "title": "afs: Clear stale peer app data after address list changes", "x_generator": { "engine": "bippy-1.2.0" } } } }