51 lines
2.7 KiB
Plaintext
51 lines
2.7 KiB
Plaintext
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URL: https://bugzilla.kernel.org/show_bug.cgi?id=97041
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Lukas Lueg 2015-04-21 21:53:14 UTC
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The btrfs-image attached to this bug causes the userland tools v3.19.1 to
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crash with a SIGFPE. The problem is that map->sub_stripes in
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__btrfs_map_block() is allowed to be 0 before entering a division.
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The userland tool crashes. The kernel reports a "divide error: 0000 ..."
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with a traceback from __btrfs_map_block()
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(gdb) run check btrfs_fukked_sigfpe_volumes:1404.bin
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Starting program: /usr/sbin/btrfs check btrfs_fukked_sigfpe_volumes:1404.bin
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[Thread debugging using libthread_db enabled]
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Using host libthread_db library "/lib64/libthread_db.so.1".
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Program received signal SIGFPE, Arithmetic exception.
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0x000000000044d7b6 in __btrfs_map_block (map_tree=map_tree@entry=0x88c170,
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rw=rw@entry=0, logical=<optimized out>, length=length@entry=0x7fffffffd8f0,
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type=type@entry=0x0, multi_ret=multi_ret@entry=0x7fffffffd8e8, mirror_num=0,
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raid_map_ret=0x0) at volumes.c:1404
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1404 int factor = map->num_stripes / map->sub_stripes;
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(gdb) bt
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#0 0x000000000044d7b6 in __btrfs_map_block (map_tree=map_tree@entry=0x88c170,
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rw=rw@entry=0, logical=<optimized out>, length=length@entry=0x7fffffffd8f0,
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type=type@entry=0x0, multi_ret=multi_ret@entry=0x7fffffffd8e8, mirror_num=0,
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raid_map_ret=0x0) at volumes.c:1404
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#1 0x000000000044db45 in btrfs_map_block (map_tree=map_tree@entry=0x88c170,
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rw=rw@entry=0, logical=<optimized out>, length=length@entry=0x7fffffffd8f0,
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multi_ret=multi_ret@entry=0x7fffffffd8e8, mirror_num=mirror_num@entry=0,
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raid_map_ret=0x0) at volumes.c:1291
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#2 0x000000000043b22d in read_whole_eb (info=0x88c010, eb=eb@entry=0x88f400,
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mirror=mirror@entry=0) at disk-io.c:232
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#3 0x000000000043caa2 in read_tree_block (root=root@entry=0x88c710,
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bytenr=<optimized out>, blocksize=<optimized out>, parent_transid=5)
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at disk-io.c:295
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#4 0x000000000043d5df in btrfs_setup_chunk_tree_and_device_map (
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fs_info=fs_info@entry=0x88c010) at disk-io.c:1106
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#5 0x000000000043d7d1 in __open_ctree_fd (fp=fp@entry=3,
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path=path@entry=0x7fffffffe1fa "btrfs_fukked_sigfpe_volumes:1404.bin",
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sb_bytenr=65536, sb_bytenr@entry=0, root_tree_bytenr=root_tree_bytenr@entry=0,
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flags=flags@entry=OPEN_CTREE_EXCLUSIVE) at disk-io.c:1190
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#6 0x000000000043d965 in open_ctree_fs_info (
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filename=0x7fffffffe1fa "btrfs_fukked_sigfpe_volumes:1404.bin",
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sb_bytenr=sb_bytenr@entry=0, root_tree_bytenr=root_tree_bytenr@entry=0,
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flags=flags@entry=OPEN_CTREE_EXCLUSIVE) at disk-io.c:1231
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#7 0x0000000000427bf5 in cmd_check (argc=1, argv=0x7fffffffde90) at cmds-check.c:9326
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#8 0x000000000040e5a2 in main (argc=2, argv=0x7fffffffde90) at btrfs.c:245
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(gdb) p map->sub_stripes
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$1 = 0
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