Re: [PATCH] ServerEngines, benet: Avoid potential null deref inbe_cmd_get_seeprom_data()

From: Ajit Khaparde
Date: Fri Feb 04 2011 - 22:19:08 EST


> From: Jesper Juhl [jj@xxxxxxxxxxxxx]
> ent: Thursday, February 03, 2011 3:27 PM
> To: netdev@xxxxxxxxxxxxxxx
> Cc: linux-drivers; linux-kernel@xxxxxxxxxxxxxxx; Khaparde, Ajit; Bandi, Sarveshwar; Seetharaman, Subramanian; Perla, Sathya
> Subject: [PATCH] ServerEngines, benet: Avoid potential null deref in be_cmd_get_seeprom_data()

> wrb_from_mccq() may return null, so we may crash on a null deref in
> be_cmd_get_seeprom_data().
> This avoids that potential crash.

> Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>

Thanks Jesper.
But because we have acquired a lock, we need to release it.
I would suggest considering the following patch.

---

[PATCH] ServerEngines, benet: Avoid potential null deref in be_cmd_get_seeprom_data()

Found by: Jesper Juhl <jj@xxxxxxxxxxxxx>

Signed-off-by: Ajit Khaparde <ajit.khaparde@xxxxxxxxxx>
---
drivers/net/benet/be_cmds.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/net/benet/be_cmds.c b/drivers/net/benet/be_cmds.c
index 0c7811f..a179cc6 100644
--- a/drivers/net/benet/be_cmds.c
+++ b/drivers/net/benet/be_cmds.c
@@ -1786,6 +1786,10 @@ int be_cmd_get_seeprom_data(struct be_adapter *adapter,
spin_lock_bh(&adapter->mcc_lock);

wrb = wrb_from_mccq(adapter);
+ if (!wrb) {
+ status = -EBUSY;
+ goto err;
+ }
req = nonemb_cmd->va;
sge = nonembedded_sgl(wrb);

@@ -1801,6 +1805,7 @@ int be_cmd_get_seeprom_data(struct be_adapter *adapter,

status = be_mcc_notify_wait(adapter);

+err:
spin_unlock_bh(&adapter->mcc_lock);
return status;
}
--
1.7.1

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