Messages in this thread | | | Date | Fri, 20 May 2016 09:45:15 -0700 (PDT) | Subject | Re: [PATCH 3.12 69/76] net: fix infoleak in rtnetlink | From | David Miller <> |
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From: Vegard Nossum <vegard.nossum@gmail.com> Date: Fri, 20 May 2016 14:04:54 +0200
> Just out of curiosity, was this observed in practice? I could be > wrong, but I was under the impression that using designated > initializers would zero the rest of the struct, including padding.
I compiled testcases and found that the compiler does not zero out padding when using designated initializers.
You can do the same.
For example, on sparc 32-bit, this code:
struct foo { int a; short b; int c; };
extern void foo(struct foo *);
void bar(void) { struct foo f = { .a = 1, .b = 2, .c = 3 };
foo(&f); }
gives:
mov 1, %g1 st %g1, [%fp-12] mov 2, %g1 sth %g1, [%fp-8] mov 3, %g1 st %g1, [%fp-4]
It does not initialize the padding between 'b' and 'c'.
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