This is a note to let you know that I've just added the patch titled
ice: fix LAG and VF lock dependency in ice_reset_vf()
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ice-fix-lag-and-vf-lock-dependency-in-ice_reset_vf.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 94dc2a40cc26a9cbb57ee939c101e67938ea0f2e
Author: Jacob Keller <jacob.e.keller@xxxxxxxxx>
Date: Tue Apr 23 11:27:20 2024 -0700
ice: fix LAG and VF lock dependency in ice_reset_vf()
[ Upstream commit 96fdd1f6b4ed72a741fb0eb705c0e13049b8721f ]
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:
======================================================
WARNING: possible circular locking dependency detected
6.8.0-rc6 #54 Tainted: G W O
------------------------------------------------------
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 mutex only after acquiring the
VF configuration lock. Fix the ice_reset_vf() to acquire the LAG mutex only
after we either acquire or check that the VF configuration lock is held.
Fixes: 9f74a3dfcf83 ("ice: Fix VF Reset paths when interface in a failed over aggregate")
Signed-off-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>
Reviewed-by: Dave Ertman <david.m.ertman@xxxxxxxxx>
Reviewed-by: Mateusz Polchlopek <mateusz.polchlopek@xxxxxxxxx>
Tested-by: Przemek Kitszel <przemyslaw.kitszel@xxxxxxxxx>
Tested-by: Rafal Romanowski <rafal.romanowski@xxxxxxxxx>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Link: https://lore.kernel.org/r/20240423182723.740401-5-anthony.l.nguyen@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/intel/ice/ice_vf_lib.c b/drivers/net/ethernet/intel/ice/ice_vf_lib.c
index d488c7156d093..03b9d7d748518 100644
--- a/drivers/net/ethernet/intel/ice/ice_vf_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_vf_lib.c
@@ -847,6 +847,11 @@ int ice_reset_vf(struct ice_vf *vf, u32 flags)
return 0;
}
+ if (flags & ICE_VF_RESET_LOCK)
+ mutex_lock(&vf->cfg_lock);
+ else
+ lockdep_assert_held(&vf->cfg_lock);
+
lag = pf->lag;
mutex_lock(&pf->lag_mutex);
if (lag && lag->bonded && lag->primary) {
@@ -858,11 +863,6 @@ int ice_reset_vf(struct ice_vf *vf, u32 flags)
act_prt = ICE_LAG_INVALID_PORT;
}
- if (flags & ICE_VF_RESET_LOCK)
- mutex_lock(&vf->cfg_lock);
- else
- lockdep_assert_held(&vf->cfg_lock);
-
if (ice_is_vf_disabled(vf)) {
vsi = ice_get_vf_vsi(vf);
if (!vsi) {
@@ -947,14 +947,14 @@ int ice_reset_vf(struct ice_vf *vf, u32 flags)
ice_mbx_clear_malvf(&vf->mbx_info);
out_unlock:
- if (flags & ICE_VF_RESET_LOCK)
- mutex_unlock(&vf->cfg_lock);
-
if (lag && lag->bonded && lag->primary &&
act_prt != ICE_LAG_INVALID_PORT)
ice_lag_move_vf_nodes_cfg(lag, pri_prt, act_prt);
mutex_unlock(&pf->lag_mutex);
+ if (flags & ICE_VF_RESET_LOCK)
+ mutex_unlock(&vf->cfg_lock);
+
return err;
}
