| Message ID | 20200803162301.103927-1-dwagner@suse.de |
|---|---|
| State | New |
| Headers | show |
| Series | qla2xxx: Reset done and free callback pointer on release | expand |
diff --git a/drivers/scsi/qla2xxx/qla_inline.h b/drivers/scsi/qla2xxx/qla_inline.h index 861dc522723c..6d41d758fc17 100644 --- a/drivers/scsi/qla2xxx/qla_inline.h +++ b/drivers/scsi/qla2xxx/qla_inline.h @@ -211,6 +211,8 @@ static inline void qla2xxx_rel_qpair_sp(struct qla_qpair *qpair, srb_t *sp) { sp->qpair = NULL; + sp->done = NULL; + sp->free = NULL; mempool_free(sp, qpair->srb_mempool); QLA_QPAIR_MARK_NOT_BUSY(qpair); }
Reset ->done and ->free when releasing the srb. There is a hidden use-after-free bug in the driver which corrupts the srb memory pool which originates from the cleanup callbacks. By explicitly resetting the callbacks to NULL, we workaround the memory corruption. An extensive search didn't bring any lights on the real problem. The initial idea was to set both pointers to NULL and try to catch invalid accesses. But instead the memory corruption was gone and the driver didn't crash. Signed-off-by: Daniel Wagner <dwagner@suse.de> --- Hi, Although I would prefer to fix the real problem, it's propably better to go with this workaround until we can fix it properly. I still hope to find the use-after-free with KASAN... Thanks, Daniel drivers/scsi/qla2xxx/qla_inline.h | 2 ++ 1 file changed, 2 insertions(+)