segfault in misc-utils/hardlink.c:1013 #2687
Description
I am working with a copy of util-linux-2.39.2, but there seems no functional difference to that file in head.
CFLAGS were "-O0 -g"
(gdb) r -cOvn --reflink=always /tmp/btrfs/chimaera*
...
[DryRun] RefLinking /tmp/btrfs/chimaera-gogs/home/gogs/forgejo/node_modules/tributejs/dist/tribute.js to /tmp/btrfs/chimaera-gogs/home/gogs/forgejo/node_modules/tributejs/example/tribute.js (-64.77 KiB)
Program received signal SIGSEGV, Segmentation fault.
0x0000555555558ba9 in is_reflink (xa=0x55555616da60, xb=0x5555581ac950)
at misc-utils/hardlink.c:1013
1013 amap->fm_extents[amap->fm_mapped_extents - 1].fe_logical +
(gdb) print amap->fm_mapped_extents
$1 = 0
I see no check to guard against fm_mapped_extents being zero.