| Message ID | 20170827063951.5975-1-christophe.jaillet@wanadoo.fr |
|---|---|
| State | Accepted |
| Delegated to: | Jeff Kirsher |
| Headers | show |
| Series | igb: check memory allocation failure | expand |
Le 28/08/2017 à 01:09, Waskiewicz Jr, Peter a écrit : > On 8/27/17 2:42 AM, Christophe JAILLET wrote: >> Check memory allocation failures and return -ENOMEM in such cases, as >> already done for other memory allocations in this function. >> >> This avoids NULL pointers dereference. >> >> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> >> --- >> drivers/net/ethernet/intel/igb/igb_main.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c >> index fd4a46b03cc8..837d9b46a390 100644 >> --- a/drivers/net/ethernet/intel/igb/igb_main.c >> +++ b/drivers/net/ethernet/intel/igb/igb_main.c >> @@ -3162,6 +3162,8 @@ static int igb_sw_init(struct igb_adapter *adapter) >> /* Setup and initialize a copy of the hw vlan table array */ >> adapter->shadow_vfta = kcalloc(E1000_VLAN_FILTER_TBL_SIZE, sizeof(u32), >> GFP_ATOMIC); >> + if (!adapter->shadow_vfta) >> + return -ENOMEM; > Looks reasonable to me. > > A larger issue though I see in this function is that if we return > -ENOMEM here, and if we return -ENOMEM from igb_init_interrupt_scheme() > below on failure, we leak adapter->mac_table (and adapter->shadow_vfta > in the latter). We should add a proper unwind to free up the memory on > failure. > > -PJ > Hi, in fact, there is no leak because the only caller of 'igb_sw_init()' (i.e. 'igb_probe()'), already frees these resources in case of error, see [1] These resources are also freed in 'igb_remove()'. Best reagrds, CJ [1]: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/net/ethernet/intel/igb/igb_main.c#n2775
> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On Behalf > Of Christophe JAILLET > Sent: Monday, August 28, 2017 10:13 AM > To: Waskiewicz Jr, Peter <peter.waskiewicz.jr@intel.com>; Kirsher, Jeffrey T > <jeffrey.t.kirsher@intel.com> > Cc: netdev@vger.kernel.org; kernel-janitors@vger.kernel.org; intel-wired- > lan@lists.osuosl.org; linux-kernel@vger.kernel.org > Subject: Re: [Intel-wired-lan] [PATCH] igb: check memory allocation failure > > Le 28/08/2017 à 01:09, Waskiewicz Jr, Peter a écrit : > > On 8/27/17 2:42 AM, Christophe JAILLET wrote: > >> Check memory allocation failures and return -ENOMEM in such cases, as > >> already done for other memory allocations in this function. > >> > >> This avoids NULL pointers dereference. > >> > >> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> > >> --- > >> drivers/net/ethernet/intel/igb/igb_main.c | 2 ++ > >> 1 file changed, 2 insertions(+) > >> This seems to be fine from a "it does not break in testing" perspective, so... Tested-by: Aaron Brown <aaron.f.brown@intel.com > > -PJ > > > Hi, > > in fact, there is no leak because the only caller of 'igb_sw_init()' > (i.e. 'igb_probe()'), already frees these resources in case of error, > see [1] > > These resources are also freed in 'igb_remove()'. > > Best reagrds, > CJ > > [1]: > https://git.kernel.org/pub/scm/linux/kernel/git/next/linux- > next.git/tree/drivers/net/ethernet/intel/igb/igb_main.c#n2775 But is PJ's comment saying that it is not really necessary? If so I tend to lean towards the don't touch it if it's not broken perspective.
On 9/13/17 7:24 PM, Brown, Aaron F wrote: >> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On Behalf >> Of Christophe JAILLET >> Sent: Monday, August 28, 2017 10:13 AM >> To: Waskiewicz Jr, Peter <peter.waskiewicz.jr@intel.com>; Kirsher, Jeffrey T >> <jeffrey.t.kirsher@intel.com> >> Cc: netdev@vger.kernel.org; kernel-janitors@vger.kernel.org; intel-wired- >> lan@lists.osuosl.org; linux-kernel@vger.kernel.org >> Subject: Re: [Intel-wired-lan] [PATCH] igb: check memory allocation failure >> >> Le 28/08/2017 à 01:09, Waskiewicz Jr, Peter a écrit : >>> On 8/27/17 2:42 AM, Christophe JAILLET wrote: >>>> Check memory allocation failures and return -ENOMEM in such cases, as >>>> already done for other memory allocations in this function. >>>> >>>> This avoids NULL pointers dereference. >>>> >>>> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> >>>> --- >>>> drivers/net/ethernet/intel/igb/igb_main.c | 2 ++ >>>> 1 file changed, 2 insertions(+) >>>> > > This seems to be fine from a "it does not break in testing" perspective, so... > > Tested-by: Aaron Brown <aaron.f.brown@intel.com > >>> -PJ >>> >> Hi, >> >> in fact, there is no leak because the only caller of 'igb_sw_init()' >> (i.e. 'igb_probe()'), already frees these resources in case of error, >> see [1] >> >> These resources are also freed in 'igb_remove()'. >> >> Best reagrds, >> CJ >> >> [1]: >> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux- >> next.git/tree/drivers/net/ethernet/intel/igb/igb_main.c#n2775 > > But is PJ's comment saying that it is not really necessary? If so I tend to lean towards the don't touch it if it's not broken perspective. I guess I didn't respond after Christophe replied, sorry about that. The patch is good to me. It's definitely catching an issue where we're not checking for a memory failure, then just follows the same de-allocation path on unwind. If you want it: Acked-by: PJ Waskiewicz <peter.waskiewicz.jr@intel.com>
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index fd4a46b03cc8..837d9b46a390 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -3162,6 +3162,8 @@ static int igb_sw_init(struct igb_adapter *adapter) /* Setup and initialize a copy of the hw vlan table array */ adapter->shadow_vfta = kcalloc(E1000_VLAN_FILTER_TBL_SIZE, sizeof(u32), GFP_ATOMIC); + if (!adapter->shadow_vfta) + return -ENOMEM; /* This call may decrease the number of queues */ if (igb_init_interrupt_scheme(adapter, true)) {
Check memory allocation failures and return -ENOMEM in such cases, as already done for other memory allocations in this function. This avoids NULL pointers dereference. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> --- drivers/net/ethernet/intel/igb/igb_main.c | 2 ++ 1 file changed, 2 insertions(+)