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Laeeth
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@Laeeth Laeeth commented Apr 15, 2016

managesieve was complaining about not knowing virtual driver for virtual namespace, which meant process kept dying (due to error in lib-storage). as a quick kludge I set the following flag in main.c for managesieve.
MAIL_STORAGE_SERVICE_FLAG_NO_NAMESPACES

However that leads to mail-namespace.c segfaulting due to deref nullptr, and I fix this here. I don't understand code base well enough for proper fix, but I guess this should not do any harm.

@sirainen
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sirainen commented Jul 5, 2016

Clarified the API behavior with bb1da4a - So although this change fixed the one specific case it's mostly just luck that the caller allowed NULL to be returned. In earlier code it could have returned NULL, but it was becoming annoying and nowadays there's this guarantee. So the crash you saw should rather be fixed at the caller level.

@sirainen sirainen closed this Jul 5, 2016
DovecotSync pushed a commit that referenced this pull request Jul 9, 2019
This fixes a race condition where the http_client_host_shared_idle_timeout()
function would get called with an already freed hshared argument.

Specifically, the situation arises from the hshared idle timeout calling
http_client_host_shared_free(), which removes the timeout and then proceeds to
free the client queue.  The client queue freeing code indirectly calls
http_client_host_shared_check_idle(), which notices that there is no idle
timeout and allocates one.

The backtrace at the point of this new timeout allocation:

    frame #3: 0x00007f0c775897f0 libdovecot.so.0`timeout_add_to(...) ioloop.c:280
    frame #4: 0x00007f0c7751a45f libdovecot.so.0`http_client_host_shared_check_idle(hshared=<unavailable>) at http-client-host.c:69
    frame #5: 0x00007f0c7750de89 libdovecot.so.0`http_client_request_error(_req=<unavailable>, status=9000, error="") at http-client-request.c:1525
    frame #6: 0x00007f0c77517f38 libdovecot.so.0`http_client_queue_fail_full(queue=0x000055e13cff0e10, status=9000, error="", all=<unavailable>) at http-client-queue.c:183
    frame #7: 0x00007f0c77518baa libdovecot.so.0`http_client_queue_free(queue=0x000055e13cff0e10) at http-client-queue.c:141
    frame #8: 0x00007f0c7751a8bc libdovecot.so.0`http_client_host_free_shared(_host=<unavailable>) at http-client-host.c:391
    frame #9: 0x00007f0c7751ab4c libdovecot.so.0`http_client_host_shared_free(_hshared=0x00007ffdac109e48) at http-client-host.c:294
    frame #10: 0x00007f0c7751ace8 libdovecot.so.0`http_client_host_shared_idle_timeout(hshared=<unavailable>) at http-client-host.c:40
    frame #11: 0x00007f0c7758a1a4 libdovecot.so.0`io_loop_handle_timeouts at ioloop.c:682
    frame #12: 0x00007f0c7758a089 libdovecot.so.0`io_loop_handle_timeouts(ioloop=0x000055e13cfc8d80) at ioloop.c:696
    frame #13: 0x00007f0c7758befc libdovecot.so.0`io_loop_handler_run_internal(ioloop=0x000055e13cfc8d80) at ioloop-select.c:126
    frame #14: 0x00007f0c7758a56d libdovecot.so.0`io_loop_handler_run(ioloop=<unavailable>) at ioloop.c:767
    frame #15: 0x00007f0c7758a798 libdovecot.so.0`io_loop_run(ioloop=0x000055e13cfc8d80) at ioloop.c:740
    frame #16: 0x00007f0c774f61eb libdovecot.so.0`master_service_run(service=0x000055e13cfc8c10, callback=<unavailable>) at master-service.c:782
    frame #17: 0x000055e13b48e3a5 stats`main(argc=<unavailable>, argv=<unavailable>) at main.c:99
    frame #18: 0x00007f0c771092e1 libc.so.6`__libc_start_main + 241
    frame #19: 0x000055e13b48e41a stats`_start + 42
DovecotSync pushed a commit that referenced this pull request Jul 9, 2019
This fixes a race condition where the http_client_host_shared_idle_timeout()
function would get called with an already freed hshared argument.

Specifically, the situation arises from the hshared idle timeout calling
http_client_host_shared_free(), which removes the timeout and then proceeds to
free the client queue.  The client queue freeing code indirectly calls
http_client_host_shared_check_idle(), which notices that there is no idle
timeout and allocates one.

The backtrace at the point of this new timeout allocation:

    frame #3: 0x00007f0c775897f0 libdovecot.so.0`timeout_add_to(...) ioloop.c:280
    frame #4: 0x00007f0c7751a45f libdovecot.so.0`http_client_host_shared_check_idle(hshared=<unavailable>) at http-client-host.c:69
    frame #5: 0x00007f0c7750de89 libdovecot.so.0`http_client_request_error(_req=<unavailable>, status=9000, error="") at http-client-request.c:1525
    frame #6: 0x00007f0c77517f38 libdovecot.so.0`http_client_queue_fail_full(queue=0x000055e13cff0e10, status=9000, error="", all=<unavailable>) at http-client-queue.c:183
    frame #7: 0x00007f0c77518baa libdovecot.so.0`http_client_queue_free(queue=0x000055e13cff0e10) at http-client-queue.c:141
    frame #8: 0x00007f0c7751a8bc libdovecot.so.0`http_client_host_free_shared(_host=<unavailable>) at http-client-host.c:391
    frame #9: 0x00007f0c7751ab4c libdovecot.so.0`http_client_host_shared_free(_hshared=0x00007ffdac109e48) at http-client-host.c:294
    frame #10: 0x00007f0c7751ace8 libdovecot.so.0`http_client_host_shared_idle_timeout(hshared=<unavailable>) at http-client-host.c:40
    frame #11: 0x00007f0c7758a1a4 libdovecot.so.0`io_loop_handle_timeouts at ioloop.c:682
    frame #12: 0x00007f0c7758a089 libdovecot.so.0`io_loop_handle_timeouts(ioloop=0x000055e13cfc8d80) at ioloop.c:696
    frame #13: 0x00007f0c7758befc libdovecot.so.0`io_loop_handler_run_internal(ioloop=0x000055e13cfc8d80) at ioloop-select.c:126
    frame #14: 0x00007f0c7758a56d libdovecot.so.0`io_loop_handler_run(ioloop=<unavailable>) at ioloop.c:767
    frame #15: 0x00007f0c7758a798 libdovecot.so.0`io_loop_run(ioloop=0x000055e13cfc8d80) at ioloop.c:740
    frame #16: 0x00007f0c774f61eb libdovecot.so.0`master_service_run(service=0x000055e13cfc8c10, callback=<unavailable>) at master-service.c:782
    frame #17: 0x000055e13b48e3a5 stats`main(argc=<unavailable>, argv=<unavailable>) at main.c:99
    frame #18: 0x00007f0c771092e1 libc.so.6`__libc_start_main + 241
    frame #19: 0x000055e13b48e41a stats`_start + 42
DovecotSync pushed a commit that referenced this pull request Jul 12, 2019
This fixes a race condition where the http_client_host_shared_idle_timeout()
function would get called with an already freed hshared argument.

Specifically, the situation arises from the hshared idle timeout calling
http_client_host_shared_free(), which removes the timeout and then proceeds to
free the client queue.  The client queue freeing code indirectly calls
http_client_host_shared_check_idle(), which notices that there is no idle
timeout and allocates one.

The backtrace at the point of this new timeout allocation:

    frame #3: 0x00007f0c775897f0 libdovecot.so.0`timeout_add_to(...) ioloop.c:280
    frame #4: 0x00007f0c7751a45f libdovecot.so.0`http_client_host_shared_check_idle(hshared=<unavailable>) at http-client-host.c:69
    frame #5: 0x00007f0c7750de89 libdovecot.so.0`http_client_request_error(_req=<unavailable>, status=9000, error="") at http-client-request.c:1525
    frame #6: 0x00007f0c77517f38 libdovecot.so.0`http_client_queue_fail_full(queue=0x000055e13cff0e10, status=9000, error="", all=<unavailable>) at http-client-queue.c:183
    frame #7: 0x00007f0c77518baa libdovecot.so.0`http_client_queue_free(queue=0x000055e13cff0e10) at http-client-queue.c:141
    frame #8: 0x00007f0c7751a8bc libdovecot.so.0`http_client_host_free_shared(_host=<unavailable>) at http-client-host.c:391
    frame #9: 0x00007f0c7751ab4c libdovecot.so.0`http_client_host_shared_free(_hshared=0x00007ffdac109e48) at http-client-host.c:294
    frame #10: 0x00007f0c7751ace8 libdovecot.so.0`http_client_host_shared_idle_timeout(hshared=<unavailable>) at http-client-host.c:40
    frame #11: 0x00007f0c7758a1a4 libdovecot.so.0`io_loop_handle_timeouts at ioloop.c:682
    frame #12: 0x00007f0c7758a089 libdovecot.so.0`io_loop_handle_timeouts(ioloop=0x000055e13cfc8d80) at ioloop.c:696
    frame #13: 0x00007f0c7758befc libdovecot.so.0`io_loop_handler_run_internal(ioloop=0x000055e13cfc8d80) at ioloop-select.c:126
    frame #14: 0x00007f0c7758a56d libdovecot.so.0`io_loop_handler_run(ioloop=<unavailable>) at ioloop.c:767
    frame #15: 0x00007f0c7758a798 libdovecot.so.0`io_loop_run(ioloop=0x000055e13cfc8d80) at ioloop.c:740
    frame #16: 0x00007f0c774f61eb libdovecot.so.0`master_service_run(service=0x000055e13cfc8c10, callback=<unavailable>) at master-service.c:782
    frame #17: 0x000055e13b48e3a5 stats`main(argc=<unavailable>, argv=<unavailable>) at main.c:99
    frame #18: 0x00007f0c771092e1 libc.so.6`__libc_start_main + 241
    frame #19: 0x000055e13b48e41a stats`_start + 42
cgzones added a commit to cgzones/core that referenced this pull request Aug 12, 2024
The input string `=0A=0D  ` contains on only four symbols: \n, \r, and
two whitespaces.

Reported by address sanitizer:

    istream qp decoder 1 ................................................. : ok
    istream qp decoder 2 ................................................. : ok
    istream qp decoder 3 ................................................. : ok
    istream qp decoder 4 ................................................. : ok
    istream qp decoder 5 ................................................. : ok
    istream qp decoder 6 ................................................. : ok
    istream qp decoder 7 ................................................. : ok
    istream qp decoder 8 ................................................. : ok
    istream qp decoder 9 ................................................. : ok
    =================================================================
    ==135439==ERROR: AddressSanitizer: global-buffer-overflow on address 0x561b9fbf5489 at pc 0x561b9fb2601d bp 0x7fffdea7cba0 sp 0x7fffdea7cb98
    READ of size 1 at 0x561b9fbf5489 thread T0
        #0 0x561b9fb2601c in get_encoding_size_diff src/lib-mail/test-istream-qp-decoder.c:76
        dovecot#1 0x561b9fb2601c in decode_test src/lib-mail/test-istream-qp-decoder.c:160
        dovecot#2 0x561b9fb2601c in test_istream_qp_decoder src/lib-mail/test-istream-qp-decoder.c:183
        dovecot#3 0x561b9fb1c97a in test_run_funcs ../lib-test/test-common.c:346
        dovecot#4 0x561b9fb1cb1a in test_run ../lib-test/test-common.c:417
        dovecot#5 0x561b9fb1cb35 in main src/lib-mail/test-istream-qp-decoder.c:196
        dovecot#6 0x7f8d59240c89  (/lib/x86_64-linux-gnu/libc.so.6+0x29c89) (BuildId: 652dfccae16d17796a09de192ed332fd65dc9abb)
        dovecot#7 0x7f8d59240d44 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29d44) (BuildId: 652dfccae16d17796a09de192ed332fd65dc9abb)
        dovecot#8 0x561b9fb05bc0 in _start (/build/dovecot-2.3.21+dfsg1/src/lib-mail/test-istream-qp-decoder+0x184bc0) (BuildId: c3eb31a408186312e51514f84e299274e772e6ae)

    0x561b9fbf5489 is located 55 bytes before global variable '*.LC247' defined in './test-istream-qp-decoder.ltrans0.ltrans' (0x561b9fbf54c0) of size 3
      '*.LC247' is ascii string '
    '
    0x561b9fbf5489 is located 0 bytes after global variable '*.LC246' defined in './test-istream-qp-decoder.ltrans0.ltrans' (0x561b9fbf5480) of size 9
      '*.LC246' is ascii string '=0A=0D  '
    SUMMARY: AddressSanitizer: global-buffer-overflow src/lib-mail/test-istream-qp-decoder.c:76 in get_encoding_size_diff
    Shadow bytes around the buggy address:
      0x561b9fbf5200: f9 f9 f9 f9 00 00 03 f9 f9 f9 f9 f9 00 00 00 01
      0x561b9fbf5280: f9 f9 f9 f9 00 00 03 f9 f9 f9 f9 f9 00 00 06 f9
      0x561b9fbf5300: f9 f9 f9 f9 00 02 f9 f9 f9 f9 f9 f9 00 00 00 02
      0x561b9fbf5380: f9 f9 f9 f9 00 00 00 00 03 f9 f9 f9 f9 f9 f9 f9
      0x561b9fbf5400: 05 f9 f9 f9 f9 f9 f9 f9 03 f9 f9 f9 f9 f9 f9 f9
    =>0x561b9fbf5480: 00[01]f9 f9 f9 f9 f9 f9 03 f9 f9 f9 f9 f9 f9 f9
      0x561b9fbf5500: 00 f9 f9 f9 f9 f9 f9 f9 03 f9 f9 f9 f9 f9 f9 f9
      0x561b9fbf5580: 05 f9 f9 f9 f9 f9 f9 f9 07 f9 f9 f9 f9 f9 f9 f9
      0x561b9fbf5600: 00 01 f9 f9 f9 f9 f9 f9 00 00 03 f9 f9 f9 f9 f9
      0x561b9fbf5680: 07 f9 f9 f9 f9 f9 f9 f9 00 00 00 04 f9 f9 f9 f9
      0x561b9fbf5700: 00 00 00 f9 f9 f9 f9 f9 07 f9 f9 f9 f9 f9 f9 f9
    Shadow byte legend (one shadow byte represents 8 application bytes):
      Addressable:           00
      Partially addressable: 01 02 03 04 05 06 07
      Heap left redzone:       fa
      Freed heap region:       fd
      Stack left redzone:      f1
      Stack mid redzone:       f2
      Stack right redzone:     f3
      Stack after return:      f5
      Stack use after scope:   f8
      Global redzone:          f9
      Global init order:       f6
      Poisoned by user:        f7
      Container overflow:      fc
      Array cookie:            ac
      Intra object redzone:    bb
      ASan internal:           fe
      Left alloca redzone:     ca
      Right alloca redzone:    cb
    ==135439==ABORTING

Fixes: e3b45a1 ("lib-mail: Extend quoted-printable decoding tests")
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