From: Quinn Tran <qutran@xxxxxxxxxxx>
System crash is observed with stack trace
warning of use after free. There are 2 signals
to tell dpc_thread to terminate (UNLOADING flag
and kthread_stop).
On setting the UNLOADING flag when dpc_thread happens to
run at the time and sees the flag, this cause dpc_thread
to exit and cleanup itself. When kthread_stop is called
for final cleanup, it cause use after free.
Remove UNLOADING signal to terminate dpc_thread.
Use the kthread_stop as the main signal to exit dpc_thread.
[596663.812935] kernel BUG at mm/slub.c:294!
[596663.812950] invalid opcode: 0000 [#1] SMP PTI
[596663.812957] CPU: 13 PID: 1475935 Comm: rmmod Kdump: loaded Tainted: G IOE --------- - - 4.18.0-240.el8.x86_64 #1
[596663.812960] Hardware name: HP ProLiant DL380p Gen8, BIOS P70 08/20/2012
[596663.812974] RIP: 0010:__slab_free+0x17d/0x360
...
[596663.813008] Call Trace:
[596663.813022] ? __dentry_kill+0x121/0x170
[596663.813030] ? _cond_resched+0x15/0x30
[596663.813034] ? _cond_resched+0x15/0x30
[596663.813039] ? wait_for_completion+0x35/0x190
[596663.813048] ? try_to_wake_up+0x63/0x540
[596663.813055] free_task+0x5a/0x60
[596663.813061] kthread_stop+0xf3/0x100
[596663.813103] qla2x00_remove_one+0x284/0x440 [qla2xxx]
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Quinn Tran <qutran@xxxxxxxxxxx>
Signed-off-by: Nilesh Javali <njavali@xxxxxxxxxxx>
---
drivers/scsi/qla2xxx/qla_os.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 7f980e6141c2..7ab717ed7232 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -6902,12 +6902,15 @@ qla2x00_do_dpc(void *data)
set_user_nice(current, MIN_NICE);
set_current_state(TASK_INTERRUPTIBLE);
- while (!kthread_should_stop()) {
+ while (1) {
ql_dbg(ql_dbg_dpc, base_vha, 0x4000,
"DPC handler sleeping.\n");
schedule();
+ if (kthread_should_stop())
+ break;
+
if (test_and_clear_bit(DO_EEH_RECOVERY, &base_vha->dpc_flags))
qla_pci_set_eeh_busy(base_vha);
@@ -6920,15 +6923,16 @@ qla2x00_do_dpc(void *data)
goto end_loop;
}
+ if (test_bit(UNLOADING, &base_vha->dpc_flags))
+ /* don't do any work. Wait to be terminated by kthread_stop */
+ goto end_loop;
+
ha->dpc_active = 1;
ql_dbg(ql_dbg_dpc + ql_dbg_verbose, base_vha, 0x4001,
"DPC handler waking up, dpc_flags=0x%lx.\n",
base_vha->dpc_flags);
- if (test_bit(UNLOADING, &base_vha->dpc_flags))
- break;
-
if (IS_P3P_TYPE(ha)) {
if (IS_QLA8044(ha)) {
if (test_and_clear_bit(ISP_UNRECOVERABLE,
@@ -7241,9 +7245,6 @@ qla2x00_do_dpc(void *data)
*/
ha->dpc_active = 0;
- /* Cleanup any residual CTX SRBs. */
- qla2x00_abort_all_cmds(base_vha, DID_NO_CONNECT << 16);
-
return 0;
}
--
2.23.1
