In the Linux kernel, the following vulnerability has been resolved:
ice: fix LAG and VF lock dependency in ice_reset_vf()
9f74a3dfcf83 (“ice: Fix VF Reset paths when interface in a failed over
aggregate”), the ice driver has acquired the LAG mutex in ice_reset_vf().
The commit placed this lock acquisition just prior to the acquisition of
the VF configuration lock.
If ice_reset_vf() acquires the configuration lock via the ICE_VF_RESET_LOCK
flag, this could deadlock with ice_vc_cfg_qs_msg() because it always
acquires the locks in the order of the VF configuration lock and then the
LAG mutex.
Lockdep reports this violation almost immediately on creating and then
removing 2 VF:
kworker/60:3/6771 is trying to acquire lock:
ff40d43e099380a0 (&vf->cfg_lock){+.+.}-{3:3}, at: ice_reset_vf+0x22f/0x4d0 [ice]
but task is already holding lock:
ff40d43ea1961210 (&pf->lag_mutex){+.+.}-{3:3}, at: ice_reset_vf+0xb7/0x4d0 [ice]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&pf->lag_mutex){+.+.}-{3:3}:
__lock_acquire+0x4f8/0xb40
lock_acquire+0xd4/0x2d0
__mutex_lock+0x9b/0xbf0
ice_vc_cfg_qs_msg+0x45/0x690 [ice]
ice_vc_process_vf_msg+0x4f5/0x870 [ice]
__ice_clean_ctrlq+0x2b5/0x600 [ice]
ice_service_task+0x2c9/0x480 [ice]
process_one_work+0x1e9/0x4d0
worker_thread+0x1e1/0x3d0
kthread+0x104/0x140
ret_from_fork+0x31/0x50
ret_from_fork_asm+0x1b/0x30
-> #0 (&vf->cfg_lock){+.+.}-{3:3}:
check_prev_add+0xe2/0xc50
validate_chain+0x558/0x800
__lock_acquire+0x4f8/0xb40
lock_acquire+0xd4/0x2d0
__mutex_lock+0x9b/0xbf0
ice_reset_vf+0x22f/0x4d0 [ice]
ice_process_vflr_event+0x98/0xd0 [ice]
ice_service_task+0x1cc/0x480 [ice]
process_one_work+0x1e9/0x4d0
worker_thread+0x1e1/0x3d0
kthread+0x104/0x140
ret_from_fork+0x31/0x50
ret_from_fork_asm+0x1b/0x30
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&pf->lag_mutex);
lock(&vf->cfg_lock);
lock(&pf->lag_mutex);
lock(&vf->cfg_lock);
*** DEADLOCK***
4 locks held by kworker/60:3/6771:
#0: ff40d43e05428b38 ((wq_completion)ice){+.+.}-{0:0}, at: process_one_work+0x176/0x4d0
#1: ff50d06e05197e58 ((work_completion)(&pf->serv_task)){+.+.}-{0:0}, at: process_one_work+0x176/0x4d0
#2: ff40d43ea1960e50 (&pf->vfs.table_lock){+.+.}-{3:3}, at: ice_process_vflr_event+0x48/0xd0 [ice]
#3: ff40d43ea1961210 (&pf->lag_mutex){+.+.}-{3:3}, at: ice_reset_vf+0xb7/0x4d0 [ice]
stack backtrace:
CPU: 60 PID: 6771 Comm: kworker/60:3 Tainted: G W O 6.8.0-rc6 #54
Hardware name:
Workqueue: ice ice_service_task [ice]
Call Trace:
<TASK>
dump_stack_lvl+0x4a/0x80
check_noncircular+0x12d/0x150
check_prev_add+0xe2/0xc50
? save_trace+0x59/0x230
? add_chain_cache+0x109/0x450
validate_chain+0x558/0x800
__lock_acquire+0x4f8/0xb40
? lockdep_hardirqs_on+0x7d/0x100
lock_acquire+0xd4/0x2d0
? ice_reset_vf+0x22f/0x4d0 [ice]
? lock_is_held_type+0xc7/0x120
__mutex_lock+0x9b/0xbf0
? ice_reset_vf+0x22f/0x4d0 [ice]
? ice_reset_vf+0x22f/0x4d0 [ice]
? rcu_is_watching+0x11/0x50
? ice_reset_vf+0x22f/0x4d0 [ice]
ice_reset_vf+0x22f/0x4d0 [ice]
? process_one_work+0x176/0x4d0
ice_process_vflr_event+0x98/0xd0 [ice]
ice_service_task+0x1cc/0x480 [ice]
process_one_work+0x1e9/0x4d0
worker_thread+0x1e1/0x3d0
? __pfx_worker_thread+0x10/0x10
kthread+0x104/0x140
? __pfx_kthread+0x10/0x10
ret_from_fork+0x31/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
To avoid deadlock, we must acquire the LAG
—truncated—
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "fd7f7a8ad336",
"lessThan": "740717774dc3",
"versionType": "git"
},
{
"status": "affected",
"version": "9f74a3dfcf83",
"lessThan": "de8631d8c9df",
"versionType": "git"
},
{
"status": "affected",
"version": "9f74a3dfcf83",
"lessThan": "96fdd1f6b4ed",
"versionType": "git"
}
],
"programFiles": [
"drivers/net/ethernet/intel/ice/ice_vf_lib.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.7"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.7",
"versionType": "custom"
},
{
"status": "unaffected",
"version": "6.6.30",
"versionType": "custom",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.8.9",
"versionType": "custom",
"lessThanOrEqual": "6.8.*"
},
{
"status": "unaffected",
"version": "6.9",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/ethernet/intel/ice/ice_vf_lib.c"
],
"defaultStatus": "affected"
}
]