From a3d86d1d7679d082ba2b28b4ad2c57a4dd362df3 Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Wed, 3 Nov 2010 01:27:24 -0700 Subject: mtd-utils: nandwrite: avoid NULL buffer pointers Commit 07005d915d6a79dbdee14b0c4360df5058c3a98b made changes to the buffer allocation in nandwrite and did not handle all affected code areas properly. In particular, we were assigning: oob.ptr = noecc ? oobreadbuf : oobbuf; However, since oobreadbuf and oobbuf are declared dynamically, they are NULL at this point. If they aren't properly assigned later, we unwittingly are passing a NULL pointer as oob buffer. This assignment line is best moved after the buffer allocations and pointer assignment. Effects of this problem can be seen when writing oob data with the "-o" flag and without the "-n" flag: $ ./nandwrite -o /dev/mtd0 img.bin Writing data to block 0 at offset 0x0 ioctl(MEMWRITEOOB): Bad address Data was only partially written due to error : Bad address Signed-off-by: Brian Norris Acked-by: Mike Frysinger Signed-off-by: Artem Bityutskiy --- nandwrite.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/nandwrite.c b/nandwrite.c index b362c29..8ec5afe 100644 --- a/nandwrite.c +++ b/nandwrite.c @@ -391,7 +391,6 @@ int main(int argc, char * const argv[]) } oob.length = mtd.oob_size; - oob.ptr = noecc ? oobreadbuf : oobbuf; /* Determine if we are reading from standard input or from a file. */ if (strcmp(img, standard_input) == 0) { @@ -594,9 +593,7 @@ int main(int argc, char * const argv[]) } } - if (noecc) { - oob.ptr = oobreadbuf; - } else { + if (!noecc) { int i, start, len; int tags_pos = 0; /* @@ -630,6 +627,7 @@ int main(int argc, char * const argv[]) } /* Write OOB data first, as ecc will be placed in there */ oob.start = mtdoffset; + oob.ptr = noecc ? oobreadbuf : oobbuf; if (ioctl(fd, MEMWRITEOOB, &oob) != 0) { perror("ioctl(MEMWRITEOOB)"); goto closeall; -- cgit v1.2.3