Messages in this thread | | | Date | Thu, 14 May 2009 20:59:39 +0800 | Subject | Re: [PATCH 1/3] kobject : kobject_set_name_vargs leak fix | From | Dave Young <> |
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On Thu, May 14, 2009 at 8:38 PM, Ming Lei <tom.leiming@gmail.com> wrote: > 2009/5/14 Dave Young <hidave.darkstar@gmail.com>: >> On Mon, May 11, 2009 at 2:16 PM, Dave Young <hidave.darkstar@gmail.com> wrote: >>> kobject_set_name_vargs will leak the old_name when return -ENOMEM, >>> move the kfree(old_name) before the return path. >> >> Hi, greg >> >> I rethought about this problem, does such issue exist really? I means >> that kobject->name != NULL scenario. >> >> there's following comments of this function: >> >> * This sets the name of the kobject. If you have already added the >> * kobject to the system, you must call kobject_rename() in order to >> * change the name of the kobject >> >> So what if something like : >> >> if (kobject->name) { >> WARN(1, KERN_WARNING, "there's name for kobject already!"); >> return -EINVAL; >> } >> >> if (!fmt) >> return 0; >> >>> >>> Signed-off-by: Dave Young <hidave.darkstar@gmail.com> >>> --- >>> lib/kobject.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff -uprN linux.old/lib/kobject.c linux.new/lib/kobject.c >>> --- linux.old/lib/kobject.c 2009-05-11 13:59:01.000000000 +0800 >>> +++ linux.new/lib/kobject.c 2009-05-11 13:59:34.000000000 +0800 >>> @@ -221,6 +221,7 @@ int kobject_set_name_vargs(struct kobjec >>> if (kobj->name && !fmt) >>> return 0; >>> >>> + kfree(old_name); >>> kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs); >>> if (!kobj->name) >>> return -ENOMEM; > > IMO, Greg means it is better that the fix should be : > if (!kobj->name) { > kobj->name = old_name; > return -ENOMEM; > } > > Right?
Hm, it's better against my original patch. I have gave up the approach.
It does not make sense for (!old_name) case , furthermore as my reply kobject with name set before should not come into this function, kobject_rename should be used instead.
> >>> @@ -229,7 +230,6 @@ int kobject_set_name_vargs(struct kobjec >>> while ((s = strchr(kobj->name, '/'))) >>> s[0] = '!'; >>> >>> - kfree(old_name); >>> return 0; >>> } >>> >> >> >> >> -- >> Regards >> dave >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ >> > > > > -- > Lei Ming >
-- Regards dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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