When iterating through an array, one must be careful to test one's index
variable rather than another similarly-named variable.
The loop will read off the end of conf->disks[] in the following
(pathological) case:
% dd bs=1 seek=840716287 if=/dev/zero of=d1 count=1
% for i in 2 3 4; do dd if=/dev/zero of=d$i bs=1k count=$(($i+150)); done
% ./vmlinux ubd0=root ubd1=d1 ubd2=d2 ubd3=d3 ubd4=d4
# mdadm -C /dev/md0 --level=linear --raid-devices=4 /dev/ubd[1234]
adding some printks, I saw this:
[42949374.960000] hash_spacing = 821120
[42949374.960000] cnt = 4
[42949374.960000] min_spacing = 801
[42949374.960000] j=0 size=820928 sz=820928
[42949374.960000] i=0 sz=820928 hash_spacing=820928
[42949374.960000] j=1 size=64 sz=64
[42949374.960000] j=2 size=64 sz=128
[42949374.960000] j=3 size=64 sz=192
[42949374.960000] j=4 size=1515870810 sz=1515871002
Cc: Gautham R Shenoy <ego@in.ibm.com>
Acked-by: Neil Brown <neilb@cse.unsw.edu.au>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bed31ed9e1