guix/gnu/packages/patches/mtools-mformat-uninitialized.patch
Ludovic Courtès 1b0b1651b1
gnu: mtools: 'mformat' initializes boot sector before writing it.
This is the last bit fixing <https://bugs.gnu.org/35283>.

Previously, 'mformat' (used by 'grub-mkrescue') would pass uninitialized
bytes to write(2), leading to non-deterministic FAT image contents.
This patch fixes that.

* gnu/packages/patches/mtools-mformat-uninitialized.patch: New file.
* gnu/packages/mtools.scm (mtools)[source]: Use it.
* gnu/local.mk (dist_patch_DATA): Add it.
2019-04-21 00:51:19 +02:00

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Diff

Fix a bug whereby 'mformat' could end up passing uninitialized bytes
to write(2). This could be reproduced with:
mformat -C -f 1440 -L 16 -N 77777777 -i /tmp/x ::
where the output of /tmp/x would be non-deterministic.
Patch by Ludovic Courtès <ludo@gnu.org>.
--- mtools-4.0.23/mformat.c 2019-04-21 00:12:01.496116195 +0200
+++ mtools-4.0.23/mformat.c 2019-04-21 00:12:36.675967157 +0200
@@ -927,6 +927,7 @@ void mformat(int argc, char **argv, int
char *endptr;
+ memset(&boot.bytes, '\0', sizeof boot);
hs = hs_set = 0;
argtracks = 0;
argheads = 0;