CVE-2024-35855

In the Linux kernel, the following vulnerability has been resolved: mlxsw:
spectrum_acl_tcam: Fix possible use-after-free during activity update The
rule activity update delayed work periodically traverses the list of
configured rules and queries their activity from the device. As part of
this task it accesses the entry pointed by ‘ventry->entry’, but this entry
can be changed concurrently by the rehash delayed work, leading to a
use-after-free [1]. Fix by closing the race and perform the activity query
under the ‘vregion->lock’ mutex. [1] BUG: KASAN: slab-use-after-free in
mlxsw_sp_acl_tcam_flower_rule_activity_get+0x121/0x140 Read of size 8 at
addr ffff8881054ed808 by task kworker/0:18/181 CPU: 0 PID: 181 Comm:
kworker/0:18 Not tainted 6.9.0-rc2-custom-00781-gd5ab772d32f7 #2 Hardware
name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019
Workqueue: mlxsw_core mlxsw_sp_acl_rule_activity_update_work Call Trace:
<TASK> dump_stack_lvl+0xc6/0x120 print_report+0xce/0x670
kasan_report+0xd7/0x110
mlxsw_sp_acl_tcam_flower_rule_activity_get+0x121/0x140
mlxsw_sp_acl_rule_activity_update_work+0x219/0x400
process_one_work+0x8eb/0x19b0 worker_thread+0x6c9/0xf70 kthread+0x2c9/0x3b0
ret_from_fork+0x4d/0x80 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by
task 1039: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30
__kasan_kmalloc+0x8f/0xa0 __kmalloc+0x19c/0x360
mlxsw_sp_acl_tcam_entry_create+0x7b/0x1f0
mlxsw_sp_acl_tcam_vchunk_migrate_all+0x30d/0xb50
mlxsw_sp_acl_tcam_vregion_rehash_work+0x157/0x1300
process_one_work+0x8eb/0x19b0 worker_thread+0x6c9/0xf70 kthread+0x2c9/0x3b0
ret_from_fork+0x4d/0x80 ret_from_fork_asm+0x1a/0x30 Freed by task 1039:
kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60 poison_slab_object+0x102/0x170
__kasan_slab_free+0x14/0x30 kfree+0xc1/0x290
mlxsw_sp_acl_tcam_vchunk_migrate_all+0x3d7/0xb50
mlxsw_sp_acl_tcam_vregion_rehash_work+0x157/0x1300
process_one_work+0x8eb/0x19b0 worker_thread+0x6c9/0xf70 kthread+0x2c9/0x3b0
ret_from_fork+0x4d/0x80 ret_from_fork_asm+0x1a/0x30