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* [PATCH] scsi: elx: libefc: potential use after free in efc_nport_vport_del()
@ 2024-08-15 11:29 Dan Carpenter
  2024-08-19  6:57 ` Daniel Wagner
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Dan Carpenter @ 2024-08-15 11:29 UTC (permalink / raw)
  To: James Smart
  Cc: James Smart, Ram Vegesna, James E.J. Bottomley,
	Martin K. Petersen, Daniel Wagner, linux-scsi, target-devel,
	linux-kernel, kernel-janitors

The kref_put() function will call nport->release if the refcount drops
to zero.  The nport->release release function is _efc_nport_free() which
frees "nport".  But then we dereference "nport" on the next line which
is a use after free.  Re-order these lines to avoid the use after free.

Fixes: fcd427303eb9 ("scsi: elx: libefc: SLI and FC PORT state machine interfaces")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
From static analysis.  Untested.  But it seems low risk.
---
 drivers/scsi/elx/libefc/efc_nport.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/elx/libefc/efc_nport.c b/drivers/scsi/elx/libefc/efc_nport.c
index 2e83a667901f..1a7437f4328e 100644
--- a/drivers/scsi/elx/libefc/efc_nport.c
+++ b/drivers/scsi/elx/libefc/efc_nport.c
@@ -705,9 +705,9 @@ efc_nport_vport_del(struct efc *efc, struct efc_domain *domain,
 	spin_lock_irqsave(&efc->lock, flags);
 	list_for_each_entry(nport, &domain->nport_list, list_entry) {
 		if (nport->wwpn == wwpn && nport->wwnn == wwnn) {
-			kref_put(&nport->ref, nport->release);
 			/* Shutdown this NPORT */
 			efc_sm_post_event(&nport->sm, EFC_EVT_SHUTDOWN, NULL);
+			kref_put(&nport->ref, nport->release);
 			break;
 		}
 	}
-- 
2.43.0


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end of thread, other threads:[~2024-08-29  2:51 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2024-08-15 11:29 [PATCH] scsi: elx: libefc: potential use after free in efc_nport_vport_del() Dan Carpenter
2024-08-19  6:57 ` Daniel Wagner
2024-08-23  1:08 ` Martin K. Petersen
2024-08-29  2:50 ` Martin K. Petersen

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