Description
In the Linux kernel, the following vulnerability has been resolved: afs: Clear stale peer app data after address list changes afs_fs_probe_fileserver() fetches the current endpoint state under server->fs_lock, but leaves old_alist as NULL. Consequently, afs_set_peer_appdata() treats every address list replacement as initial setup and only binds the new peers; it never unbinds peers removed from the old list. An address refresh can therefore proceed as follows. CPU 0 replaces server S's list and drops Pold without clearing Pold->app_data. The server destroyer then clears only S's current peers and lets S reach its RCU callback. After the callback frees S, CPU 1 handles a callback through an RxRPC connection that still pins Pold, reads Pold->app_data, and calls afs_use_server() on the freed object. KASAN reported: BUG: KASAN: slab-use-after-free in afs_find_server+0x3c/0xa0 Read of size 4 at addr ffff8881013e1af0 by task krxrpcio/7001/74 Call Trace: afs_find_server+0x3c/0xa0 afs_rx_new_call+0x15c/0x390 rxrpc_new_incoming_call+0x97c/0x1730 rxrpc_input_packet.constprop.0+0xd03/0xec0 rxrpc_io_thread+0x967/0x1640 Allocated by task 93: afs_lookup_server+0x1a7/0x14c0 afs_alloc_server_list+0x43f/0xb60 afs_create_volume+0x923/0x1490 afs_get_tree+0x1c6/0x10a0 Freed by task 0: kfree+0x131/0x3c0 rcu_core+0x50a/0x1850 Last potentially related work creation: __call_rcu_common.constprop.0+0x71/0xa10 afs_put_server+0x213/0x2b0 Preserve old->addresses for the peer app-data update so that removed peers are cleared before the endpoint state is replaced. Also advance both cursors when the old and new lists share a peer; activating the old/new comparison without this would otherwise loop forever on the shared entry.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
39ba6af83a7f9dee3e6a7916f41a48bcbda54eba to < 3afb988fd0411707bdafb9b321086fff0da28aaeaffected40e8b52fe8c8ab6920ea5f59c5469b6918cce624 to < c7f77a11a1e719192c7262aad38a3919aec62c21affected40e8b52fe8c8ab6920ea5f59c5469b6918cce624 to < 7f7f5589d048821dea316cbac9b37d27eaf7530eaffected40e8b52fe8c8ab6920ea5f59c5469b6918cce624 to < ba0623fc19a424f4745394c499f9f28a8d88d397affected6.12.101 to < 6.12.111affected
Linux Linux
Default version status: affected
6.15affected0 to < 6.15unaffected6.12.111 to ≤ 6.12.*unaffected6.18.53 to ≤ 6.18.*unaffected7.2.7 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected