Created attachment 174931 [details] btfs-image causing userland tools to segfault after using uninitialized memory Running btrfs-progs v3.19.1 The btrfs-image attached to this bug causes the btrfs-userland tool to use uninitialized memory and ultimately overwrite what seems to be arbitrary memory locations, dying in the process. Reproduced on x86-64 and i686. The kernel seems to be less affected and fails to mount the image. If /usr/sbin/btrfs is not setuid (which it probably never is), things should be safe. I didn't investigate further though. gdb output: GNU gdb (GDB) Fedora 7.8.2-38.fc21 [... lots of other errors...] Ignoring transid failure root 5 inode 260 errors 1000, some csum missing unresolved ref dir 256 index 7 namelen 5 name b.bin filetype 1 errors 2, no dir index unresolved ref dir 256 index 7 namelen 5 name b.fin filetype 1 errors 5, no dir item, no inode ref root 5 inode 261 errors 200, dir isize wrong Program received signal SIGSEGV, Segmentation fault. 0x000000000089bb70 in ?? () (gdb) bt #0 0x000000000089bb70 in ?? () #1 0x00007fffffffdb50 in ?? () #2 0x0000000000894b20 in ?? () #3 0x00000032629b88e0 in _IO_2_1_stdout_ () from /lib64/libc.so.6 #4 0x000000000088c010 in ?? () #5 0x0000000000000000 in ?? () valgrind output: [...lots of errors...] ==12638== Conditional jump or move depends on uninitialised value(s) ==12638== at 0x436E77: check_block.part.14 (ctree.c:548) ==12638== by 0x438954: UnknownInlinedFun (kerncompat.h:91) ==12638== by 0x438954: btrfs_search_slot (ctree.c:1120) ==12638== by 0x40DD1F: count_csum_range (cmds-check.c:1419) ==12638== by 0x40DD1F: process_file_extent (cmds-check.c:1551) ==12638== by 0x40DD1F: process_one_leaf (cmds-check.c:1617) ==12638== by 0x40DD1F: walk_down_tree (cmds-check.c:1742) ==12638== by 0x40DD1F: check_fs_root (cmds-check.c:3380) ==12638== by 0x40DD1F: check_fs_roots.isra.51 (cmds-check.c:3516) ==12638== by 0x4C64B0F: ??? ==12638== by 0x4C30A2F: ??? ==12638== by 0x4C468CF: ??? ==12638== by 0x32629B88DF: ??? (in /usr/lib64/libc-2.20.so) ==12638== by 0x4C3657F: ??? ==12638== ==12638== Conditional jump or move depends on uninitialised value(s) ==12638== at 0x4A0B0E7: memcpy@@GLIBC_2.14 (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==12638== by 0x436E99: UnknownInlinedFun (ctree.h:1613) ==12638== by 0x436E99: check_block.part.14 (ctree.c:550) ==12638== by 0x438954: UnknownInlinedFun (kerncompat.h:91) ==12638== by 0x438954: btrfs_search_slot (ctree.c:1120) ==12638== by 0x40DD1F: count_csum_range (cmds-check.c:1419) ==12638== by 0x40DD1F: process_file_extent (cmds-check.c:1551) ==12638== by 0x40DD1F: process_one_leaf (cmds-check.c:1617) ==12638== by 0x40DD1F: walk_down_tree (cmds-check.c:1742) ==12638== by 0x40DD1F: check_fs_root (cmds-check.c:3380) ==12638== by 0x40DD1F: check_fs_roots.isra.51 (cmds-check.c:3516) ==12638== by 0x4C64B0F: ??? ==12638== by 0x4C30A2F: ??? ==12638== by 0x4C468CF: ??? ==12638== by 0x32629B88DF: ??? (in /usr/lib64/libc-2.20.so) ==12638== by 0x4C3657F: ??? ==12638== ==12638== Conditional jump or move depends on uninitialised value(s) ==12638== at 0x4A0B2AC: memcpy@@GLIBC_2.14 (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==12638== by 0x436E99: UnknownInlinedFun (ctree.h:1613) ==12638== by 0x436E99: check_block.part.14 (ctree.c:550) ==12638== by 0x438954: UnknownInlinedFun (kerncompat.h:91) ==12638== by 0x438954: btrfs_search_slot (ctree.c:1120) ==12638== by 0x40DD1F: count_csum_range (cmds-check.c:1419) ==12638== by 0x40DD1F: process_file_extent (cmds-check.c:1551) ==12638== by 0x40DD1F: process_one_leaf (cmds-check.c:1617) ==12638== by 0x40DD1F: walk_down_tree (cmds-check.c:1742) ==12638== by 0x40DD1F: check_fs_root (cmds-check.c:3380) ==12638== by 0x40DD1F: check_fs_roots.isra.51 (cmds-check.c:3516) ==12638== by 0x4C64B0F: ??? ==12638== by 0x4C30A2F: ??? ==12638== by 0x4C468CF: ??? ==12638== by 0x32629B88DF: ??? (in /usr/lib64/libc-2.20.so) ==12638== by 0x4C3657F: ??? ==12638== ==12638== Conditional jump or move depends on uninitialised value(s) ==12638== at 0x4A0B151: memcpy@@GLIBC_2.14 (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==12638== by 0x436E99: UnknownInlinedFun (ctree.h:1613) ==12638== by 0x436E99: check_block.part.14 (ctree.c:550) ==12638== by 0x438954: UnknownInlinedFun (kerncompat.h:91) ==12638== by 0x438954: btrfs_search_slot (ctree.c:1120) ==12638== by 0x40DD1F: count_csum_range (cmds-check.c:1419) ==12638== by 0x40DD1F: process_file_extent (cmds-check.c:1551) ==12638== by 0x40DD1F: process_one_leaf (cmds-check.c:1617) ==12638== by 0x40DD1F: walk_down_tree (cmds-check.c:1742) ==12638== by 0x40DD1F: check_fs_root (cmds-check.c:3380) ==12638== by 0x40DD1F: check_fs_roots.isra.51 (cmds-check.c:3516) ==12638== by 0x4C64B0F: ??? ==12638== by 0x4C30A2F: ??? ==12638== by 0x4C468CF: ??? ==12638== by 0x32629B88DF: ??? (in /usr/lib64/libc-2.20.so) ==12638== by 0x4C3657F: ??? ==12638== ==12638== Conditional jump or move depends on uninitialised value(s) ==12638== at 0x4A0B162: memcpy@@GLIBC_2.14 (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==12638== by 0x436E99: UnknownInlinedFun (ctree.h:1613) ==12638== by 0x436E99: check_block.part.14 (ctree.c:550) ==12638== by 0x438954: UnknownInlinedFun (kerncompat.h:91) ==12638== by 0x438954: btrfs_search_slot (ctree.c:1120) ==12638== by 0x40DD1F: count_csum_range (cmds-check.c:1419) ==12638== by 0x40DD1F: process_file_extent (cmds-check.c:1551) ==12638== by 0x40DD1F: process_one_leaf (cmds-check.c:1617) ==12638== by 0x40DD1F: walk_down_tree (cmds-check.c:1742) ==12638== by 0x40DD1F: check_fs_root (cmds-check.c:3380) ==12638== by 0x40DD1F: check_fs_roots.isra.51 (cmds-check.c:3516) ==12638== by 0x4C64B0F: ??? ==12638== by 0x4C30A2F: ??? ==12638== by 0x4C468CF: ??? ==12638== by 0x32629B88DF: ??? (in /usr/lib64/libc-2.20.so) ==12638== by 0x4C3657F: ??? ==12638== ==12638== Conditional jump or move depends on uninitialised value(s) ==12638== at 0x4A0B176: memcpy@@GLIBC_2.14 (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==12638== by 0x436E99: UnknownInlinedFun (ctree.h:1613) ==12638== by 0x436E99: check_block.part.14 (ctree.c:550) ==12638== by 0x438954: UnknownInlinedFun (kerncompat.h:91) ==12638== by 0x438954: btrfs_search_slot (ctree.c:1120) ==12638== by 0x40DD1F: count_csum_range (cmds-check.c:1419) ==12638== by 0x40DD1F: process_file_extent (cmds-check.c:1551) ==12638== by 0x40DD1F: process_one_leaf (cmds-check.c:1617) ==12638== by 0x40DD1F: walk_down_tree (cmds-check.c:1742) ==12638== by 0x40DD1F: check_fs_root (cmds-check.c:3380) ==12638== by 0x40DD1F: check_fs_roots.isra.51 (cmds-check.c:3516) ==12638== by 0x4C64B0F: ??? ==12638== by 0x4C30A2F: ??? ==12638== by 0x4C468CF: ??? ==12638== by 0x32629B88DF: ??? (in /usr/lib64/libc-2.20.so) ==12638== by 0x4C3657F: ??? ==12638== ==12638== Conditional jump or move depends on uninitialised value(s) ==12638== at 0x4A0B2CE: memcpy@@GLIBC_2.14 (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==12638== by 0x436E99: UnknownInlinedFun (ctree.h:1613) ==12638== by 0x436E99: check_block.part.14 (ctree.c:550) ==12638== by 0x438954: UnknownInlinedFun (kerncompat.h:91) ==12638== by 0x438954: btrfs_search_slot (ctree.c:1120) ==12638== by 0x40DD1F: count_csum_range (cmds-check.c:1419) ==12638== by 0x40DD1F: process_file_extent (cmds-check.c:1551) ==12638== by 0x40DD1F: process_one_leaf (cmds-check.c:1617) ==12638== by 0x40DD1F: walk_down_tree (cmds-check.c:1742) ==12638== by 0x40DD1F: check_fs_root (cmds-check.c:3380) ==12638== by 0x40DD1F: check_fs_roots.isra.51 (cmds-check.c:3516) ==12638== by 0x4C64B0F: ??? ==12638== by 0x4C30A2F: ??? ==12638== by 0x4C468CF: ??? ==12638== by 0x32629B88DF: ??? (in /usr/lib64/libc-2.20.so) ==12638== by 0x4C3657F: ??? ==12638== ==12638== Conditional jump or move depends on uninitialised value(s) ==12638== at 0x4A0B34A: memcpy@@GLIBC_2.14 (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==12638== by 0x436E99: UnknownInlinedFun (ctree.h:1613) ==12638== by 0x436E99: check_block.part.14 (ctree.c:550) ==12638== by 0x438954: UnknownInlinedFun (kerncompat.h:91) ==12638== by 0x438954: btrfs_search_slot (ctree.c:1120) ==12638== by 0x40DD1F: count_csum_range (cmds-check.c:1419) ==12638== by 0x40DD1F: process_file_extent (cmds-check.c:1551) ==12638== by 0x40DD1F: process_one_leaf (cmds-check.c:1617) ==12638== by 0x40DD1F: walk_down_tree (cmds-check.c:1742) ==12638== by 0x40DD1F: check_fs_root (cmds-check.c:3380) ==12638== by 0x40DD1F: check_fs_roots.isra.51 (cmds-check.c:3516) ==12638== by 0x4C64B0F: ??? ==12638== by 0x4C30A2F: ??? ==12638== by 0x4C468CF: ??? ==12638== by 0x32629B88DF: ??? (in /usr/lib64/libc-2.20.so) ==12638== by 0x4C3657F: ??? ==12638== ==12638== Use of uninitialised value of size 8 ==12638== at 0x4A0B3A0: memcpy@@GLIBC_2.14 (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==12638== by 0x436E99: UnknownInlinedFun (ctree.h:1613) ==12638== by 0x436E99: check_block.part.14 (ctree.c:550) ==12638== by 0x438954: UnknownInlinedFun (kerncompat.h:91) ==12638== by 0x438954: btrfs_search_slot (ctree.c:1120) ==12638== by 0x40DD1F: count_csum_range (cmds-check.c:1419) ==12638== by 0x40DD1F: process_file_extent (cmds-check.c:1551) ==12638== by 0x40DD1F: process_one_leaf (cmds-check.c:1617) ==12638== by 0x40DD1F: walk_down_tree (cmds-check.c:1742) ==12638== by 0x40DD1F: check_fs_root (cmds-check.c:3380) ==12638== by 0x40DD1F: check_fs_roots.isra.51 (cmds-check.c:3516) ==12638== by 0x4C64B0F: ??? ==12638== by 0x4C30A2F: ??? ==12638== by 0x4C468CF: ??? ==12638== by 0x32629B88DF: ??? (in /usr/lib64/libc-2.20.so) ==12638== by 0x4C3657F: ??? ==12638== ==12638== Invalid read of size 1 ==12638== at 0x4A0B3A0: memcpy@@GLIBC_2.14 (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==12638== by 0x436E99: UnknownInlinedFun (ctree.h:1613) ==12638== by 0x436E99: check_block.part.14 (ctree.c:550) ==12638== by 0x438954: UnknownInlinedFun (kerncompat.h:91) ==12638== by 0x438954: btrfs_search_slot (ctree.c:1120) ==12638== by 0x40DD1F: count_csum_range (cmds-check.c:1419) ==12638== by 0x40DD1F: process_file_extent (cmds-check.c:1551) ==12638== by 0x40DD1F: process_one_leaf (cmds-check.c:1617) ==12638== by 0x40DD1F: walk_down_tree (cmds-check.c:1742) ==12638== by 0x40DD1F: check_fs_root (cmds-check.c:3380) ==12638== by 0x40DD1F: check_fs_roots.isra.51 (cmds-check.c:3516) ==12638== by 0x4C64B0F: ??? ==12638== by 0x4C30A2F: ??? ==12638== by 0x4C468CF: ??? ==12638== by 0x32629B88DF: ??? (in /usr/lib64/libc-2.20.so) ==12638== by 0x4C3657F: ??? ==12638== Address 0xa25c9de9 is not stack'd, malloc'd or (recently) free'd ==12638== ==12638== ==12638== Process terminating with default action of signal 11 (SIGSEGV) ==12638== Access not within mapped region at address 0xA25C9DE9 ==12638== at 0x4A0B3A0: memcpy@@GLIBC_2.14 (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==12638== by 0x436E99: UnknownInlinedFun (ctree.h:1613) ==12638== by 0x436E99: check_block.part.14 (ctree.c:550) ==12638== by 0x438954: UnknownInlinedFun (kerncompat.h:91) ==12638== by 0x438954: btrfs_search_slot (ctree.c:1120) ==12638== by 0x40DD1F: count_csum_range (cmds-check.c:1419) ==12638== by 0x40DD1F: process_file_extent (cmds-check.c:1551) ==12638== by 0x40DD1F: process_one_leaf (cmds-check.c:1617) ==12638== by 0x40DD1F: walk_down_tree (cmds-check.c:1742) ==12638== by 0x40DD1F: check_fs_root (cmds-check.c:3380) ==12638== by 0x40DD1F: check_fs_roots.isra.51 (cmds-check.c:3516) ==12638== by 0x4C64B0F: ??? ==12638== by 0x4C30A2F: ??? ==12638== by 0x4C468CF: ??? ==12638== by 0x32629B88DF: ??? (in /usr/lib64/libc-2.20.so) ==12638== by 0x4C3657F: ??? ==12638== If you believe this happened as a result of a stack ==12638== overflow in your program's main thread (unlikely but ==12638== possible), you can try to increase the size of the ==12638== main thread stack using the --main-stacksize= flag. ==12638== The main thread stack size used in this run was 8388608. ==12638== ==12638== HEAP SUMMARY: ==12638== in use at exit: 46,260 bytes in 56 blocks ==12638== total heap usage: 380 allocs, 324 frees, 218,054 bytes allocated ==12638== ==12638== LEAK SUMMARY: ==12638== definitely lost: 272 bytes in 2 blocks ==12638== indirectly lost: 800 bytes in 8 blocks ==12638== possibly lost: 88 bytes in 1 blocks ==12638== still reachable: 45,100 bytes in 45 blocks ==12638== suppressed: 0 bytes in 0 blocks ==12638== Rerun with --leak-check=full to see details of leaked memory ==12638== ==12638== For counts of detected and suppressed errors, rerun with: -v ==12638== Use --track-origins=yes to see where uninitialised values come from ==12638== ERROR SUMMARY: 10 errors from 10 contexts (suppressed: 0 from 0) [1] 12638 segmentation fault valgrind btrfs check btrfs_fukked_memorycorruption.bin
Fix applied to btrfs-progs git. Thanks.
As of c061b303c08af7a58373908d0d77ef0f1161fd36 the problem is still there.