Messages in this thread Patch in this message | | | Date | Sat, 27 Apr 2019 23:49:25 +0200 | From | Greg KH <> | Subject | Re: EDAC: Fix memory leak in creating CSROW object |
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On Fri, Apr 19, 2019 at 02:45:16AM +0200, Borislav Petkov wrote: > On Fri, Apr 19, 2019 at 08:35:36AM +0800, PanBian wrote: > > Yes, I see that. Because the loop start with (--i), there is no put > > operation for the device that fails to create. So, I think we cannot > > rule out the possibility of memory leak. > > Ok, so this is not something you trigger - you're basically staring at > the code? > > Well, there's something else questionable in that code which I asked > Greg about today but we didn't finish that conversation, let me CC him. > > So AFAIU, devices for which device_add() has returned success, > should be removed with their counterpart device_del(). > edac_create_csrow_objects(), however, does put_device() on those in the > "unwinding" loop. > > And for the case where device_add() fails, you should do put_device() to > it. I.e., what you're saying. > > So I think we need to figure what needs to be done when before fixing > this properly. > > Greg?
How about this patch, I think it fixes up everything you need to do here, right?
diff --git a/drivers/edac/edac_mc_sysfs.c b/drivers/edac/edac_mc_sysfs.c index 464174685589..0fb2d1de6d0e 100644 --- a/drivers/edac/edac_mc_sysfs.c +++ b/drivers/edac/edac_mc_sysfs.c @@ -404,6 +404,8 @@ static inline int nr_pages_per_csrow(struct csrow_info *csrow) static int edac_create_csrow_object(struct mem_ctl_info *mci, struct csrow_info *csrow, int index) { + int retval; + csrow->dev.type = &csrow_attr_type; csrow->dev.groups = csrow_dev_groups; device_initialize(&csrow->dev); @@ -415,7 +417,10 @@ static int edac_create_csrow_object(struct mem_ctl_info *mci, edac_dbg(0, "creating (virtual) csrow node %s\n", dev_name(&csrow->dev)); - return device_add(&csrow->dev); + retval = device_add(&csrow->dev); + if (retval) + put_device(&csrow->dev); + return retval; } /* Create a CSROW object under specifed edac_mc_device */ @@ -649,6 +654,8 @@ static int edac_create_dimm_object(struct mem_ctl_info *mci, edac_dbg(0, "creating rank/dimm device %s\n", dev_name(&dimm->dev)); + if (err) + put_device(&dimm->dev); return err; } @@ -928,6 +935,7 @@ int edac_create_sysfs_mci_device(struct mem_ctl_info *mci, err = device_add(&mci->dev); if (err < 0) { edac_dbg(1, "failure: create device %s\n", dev_name(&mci->dev)); + put_device(mci->dev); goto out; }
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