--- /dev/null
+URL: https://bugzilla.kernel.org/show_bug.cgi?id=97031
+Lukas Lueg 2015-04-21 21:47:18 UTC
+
+The btrfs-image attached to this bug causes the userland tools v3.19.1 to crash
+with a SIGFPE. The problem is that map->stripe_len in __btrfs_map_block() is
+allowed to be 0 before entering a division.
+
+The userland tool crashes.
+The kernel fails to mount with
+> BTRFS: failed to read the system array on loop0
+> BTRFS: open_ctree_failed
+
+
+
+(gdb) run check btrfs_fukked_sigfpe_volumes:1372.bin
+....
+warning, device 0 is missing
+warning, device 4294967295 is missing
+warning, device 0 is missing
+warning, device 0 is missing
+warning, device 0 is missing
+warning, device 0 is missing
+warning, device 4294967295 is missing
+
+Program received signal SIGFPE, Arithmetic exception.
+0x000000000044d56f in __btrfs_map_block (map_tree=map_tree@entry=0x88c170,
+ rw=rw@entry=0, logical=<optimized out>, length=length@entry=0x7fffffffd8f0,
+ type=type@entry=0x0, multi_ret=multi_ret@entry=0x7fffffffd8e8, mirror_num=0,
+ raid_map_ret=0x0) at volumes.c:1372
+1372 stripe_nr = stripe_nr / map->stripe_len;
+(gdb) bt
+#0 0x000000000044d56f in __btrfs_map_block (map_tree=map_tree@entry=0x88c170,
+ rw=rw@entry=0, logical=<optimized out>, length=length@entry=0x7fffffffd8f0,
+ type=type@entry=0x0, multi_ret=multi_ret@entry=0x7fffffffd8e8, mirror_num=0,
+ raid_map_ret=0x0) at volumes.c:1372
+#1 0x000000000044db45 in btrfs_map_block (map_tree=map_tree@entry=0x88c170,
+ rw=rw@entry=0, logical=<optimized out>, length=length@entry=0x7fffffffd8f0,
+ multi_ret=multi_ret@entry=0x7fffffffd8e8, mirror_num=mirror_num@entry=0,
+ raid_map_ret=0x0) at volumes.c:1291
+#2 0x000000000043b22d in read_whole_eb (info=0x88c010, eb=eb@entry=0x88f400,
+ mirror=mirror@entry=0) at disk-io.c:232
+#3 0x000000000043caa2 in read_tree_block (root=root@entry=0x88c710,
+ bytenr=<optimized out>, blocksize=<optimized out>, parent_transid=5)
+ at disk-io.c:295
+#4 0x000000000043d5df in btrfs_setup_chunk_tree_and_device_map (
+ fs_info=fs_info@entry=0x88c010) at disk-io.c:1106
+#5 0x000000000043d7d1 in __open_ctree_fd (fp=fp@entry=3,
+ path=path@entry=0x7fffffffe1fa "btrfs_fukked_sigfpe_volumes:1372.bin",
+ sb_bytenr=65536, sb_bytenr@entry=0, root_tree_bytenr=root_tree_bytenr@entry=0,
+ flags=flags@entry=OPEN_CTREE_EXCLUSIVE) at disk-io.c:1190
+#6 0x000000000043d965 in open_ctree_fs_info (
+ filename=0x7fffffffe1fa "btrfs_fukked_sigfpe_volumes:1372.bin",
+ sb_bytenr=sb_bytenr@entry=0, root_tree_bytenr=root_tree_bytenr@entry=0,
+ flags=flags@entry=OPEN_CTREE_EXCLUSIVE) at disk-io.c:1231
+#7 0x0000000000427bf5 in cmd_check (argc=1, argv=0x7fffffffde90) at cmds-check.c:9326
+#8 0x000000000040e5a2 in main (argc=2, argv=0x7fffffffde90) at btrfs.c:245
+(gdb) p map->stripe_len
+$1 = 0