On 05/27/15 03:06, vasu.dev@xxxxxxxxxxxxxxx wrote:
> I'm trying to look back but may be you can help me why we added
> lport_recv() along adding of fc_invoke_resp() by you in commit 7030fd62.
>
> I'm digging at history since it has been while since you added
> fc_invoke_resp() logic. Looks like you had lport_recv() called only when
> fc_invoke_resp() was not done calling upper later fcp handler but then
> you added fp free there and thats where this bug got introduced but not
> sure lport_recv() calling was for a reason which you had it left along
> adding fc_invoke_resp().
Hello Vasu,
The lport_recv() call wasn't added by me. Anyway, how about replacing patch
3/4 with the patch below ?
Thanks,
Bart.
[PATCH] libfc: Fix fc_exch_recv_req() error path
Due to patch "libfc: Do not invoke the response handler after
fc_exch_done()" (commit ID f65fc5770adc) the lport_recv() call
in fc_exch_recv_req() is passed a dangling pointer. Avoid this
by moving the fc_frame_free() call from fc_invoke_resp() to its
callers. This patch fixes the following crash:
general protection fault: 0000 [#3] PREEMPT SMP
RIP: fc_lport_recv_req+0x72/0x280 [libfc]
Call Trace:
fc_exch_recv+0x642/0xde0 [libfc]
fcoe_percpu_receive_thread+0x46a/0x5ed [fcoe]
kthread+0x10a/0x120
ret_from_fork+0x42/0x70
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Cc: Vasu Dev <vasu.dev@xxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
---
drivers/scsi/libfc/fc_exch.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index 1b3a094..30f9ef0 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -733,8 +733,6 @@ static bool fc_invoke_resp(struct fc_exch *ep, struct fc_seq *sp,
if (resp) {
resp(sp, fp, arg);
res = true;
- } else if (!IS_ERR(fp)) {
- fc_frame_free(fp);
}
spin_lock_bh(&ep->ex_lock);
@@ -1596,7 +1594,8 @@ static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
* If new exch resp handler is valid then call that
* first.
*/
- fc_invoke_resp(ep, sp, fp);
+ if (!fc_invoke_resp(ep, sp, fp))
+ fc_frame_free(fp);
fc_exch_release(ep);
return;
@@ -1695,7 +1694,8 @@ static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
fc_exch_hold(ep);
if (!rc)
fc_exch_delete(ep);
- fc_invoke_resp(ep, sp, fp);
+ if (!fc_invoke_resp(ep, sp, fp))
+ fc_frame_free(fp);
if (has_rec)
fc_exch_timer_set(ep, ep->r_a_tov);
fc_exch_release(ep);
--
2.1.4
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