Messages in this thread | | | Date | Wed, 04 Feb 2009 17:48:42 -0600 | From | Robert Hancock <> | Subject | Re: [PATCH] Kbuild: Disable the -Wformat-security gcc flag |
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Roland Dreier wrote: > > Before judging on this patch could you please post what warning it > > triggers and one or a few patches to fix some of them. > > The warnings are things like: > > init/main.c: In function 'start_kernel': > init/main.c:557: warning: format not a string literal and no format arguments > > where the patch to fix this would be: > > diff --git a/init/main.c b/init/main.c > index 8442094..78fc0d8 100644 > --- a/init/main.c > +++ b/init/main.c > @@ -554,7 +554,7 @@ asmlinkage void __init start_kernel(void) > boot_cpu_init(); > page_address_init(); > printk(KERN_NOTICE); > - printk(linux_banner); > + printk("%s", linux_banner); > setup_arch(&command_line); > mm_init_owner(&init_mm, &init_task); > setup_command_line(command_line); > > with the impact: > > add/remove: 0/0 grow/shrink: 1/0 up/down: 7/0 (7) > function old new delta > start_kernel 689 696 +7
Just how many of these warnings are showing up? In the cases you posted it's presumably no problem, but if the string could either a) be potentially set by a malicious user or b) accidentally contain printk format characters then this code has a risk that things could blow up..
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