Messages in this thread | | | Date | Mon, 26 Dec 2022 21:52:12 -0800 | From | Guenter Roeck <> | Subject | Re: Linux 6.2-rc1 |
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On Mon, Dec 26, 2022 at 05:32:28PM -0800, Kees Cook wrote: > On December 26, 2022 4:29:41 PM PST, Guenter Roeck <linux@roeck-us.net> wrote: > >On Mon, Dec 26, 2022 at 01:03:59PM -0800, Kees Cook wrote: > >> On December 26, 2022 12:56:29 PM PST, Linus Torvalds <torvalds@linux-foundation.org> wrote: > >> >On Mon, Dec 26, 2022 at 11:52 AM Guenter Roeck <linux@roeck-us.net> wrote: > >> >> > >> >> fs/f2fs/inline.c: In function 'f2fs_move_inline_dirents': > >> >> include/linux/fortify-string.h:59:33: error: '__builtin_memset' pointer overflow between offset [28, 898293814] and size [-898293787, -1] [-Werror=array-bounds] > >> >> fs/f2fs/inline.c:430:9: note: in expansion of macro 'memset' > >> >> 430 | memset(dst.bitmap + src.nr_bitmap, 0, dst.nr_bitmap - src.nr_bitmap); > >> >> | ^~~~~~ > >> > > >> >Well, that's unfortunate. > >> > >> I'll look into this. > >> > > > >I did some more testing. The problem is seen with gcc 11.3.0, but not with > >gcc 12.2.0 nor with gcc 10.3.0. > > That's what I'd expect: 10 didn't have variable range tracking wired up to -Warray-bounds, 11 does, and we disable -Warray-bounds on 12 because of 3 separate 12-only GCC bugs. > > > gcc bug ? Should I switch to gcc 12.2.0 for > >powerpc when build testing the latest kernel ? > > Sure? But that'll just hide it. I suspect GCC has found a way for dst.nr_bitmap to be compile-time 27, so the size is always negative. > dst.nr_bitmap is initialized with SIZE_OF_DENTRY_BITMAP, which is defined as:
#define NR_DENTRY_IN_BLOCK 214 /* the number of dentry in a block */ #define SIZE_OF_DIR_ENTRY 11 /* by byte */ #define SIZE_OF_DENTRY_BITMAP ((NR_DENTRY_IN_BLOCK + BITS_PER_BYTE - 1) / \ BITS_PER_BYTE)
((214 + 8 - 1) / 8 = 27, so dst.nr_bitmap is indeed compile-time 27.
Not sure how would know that src.nr_bitmap can be > 27, though. Am I missing something ?
Thanks, Guenter
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