Bug 103437 - Syscall param sendmsg(msg.msg_iov[0]) points to uninitialised byte(s)
Summary: Syscall param sendmsg(msg.msg_iov[0]) points to uninitialised byte(s)
Alias: None
Product: Wayland
Classification: Unclassified
Component: wayland (show other bugs)
Version: unspecified
Hardware: Other All
: medium normal
Assignee: Wayland bug list
QA Contact:
Depends on:
Reported: 2017-10-24 19:35 UTC by Sebastien Bacher
Modified: 2018-06-08 23:48 UTC (History)
0 users

See Also:
i915 platform:
i915 features:


Description Sebastien Bacher 2017-10-24 19:35:20 UTC
Using gnome-software under valgrind on Ubuntu 17.10 that error got listed

==8911== Syscall param sendmsg(msg.msg_iov[0]) points to uninitialised byte(s)
==8911==    at 0x82DBEF0: sendmsg (sendmsg.c:28)
==8911==    by 0xC87C15C: wl_connection_flush.part.3 (connection.c:300)
==8911==    by 0xC87B987: wl_display_flush (wayland-client.c:1869)
==8911==    by 0x6764032: gdk_event_source_prepare (gdkeventsource.c:65)
==8911==    by 0x55506A7: g_main_context_prepare (gmain.c:3450)
==8911==    by 0x555109A: g_main_context_iterate.isra.30 (gmain.c:3866)
==8911==    by 0x555127B: g_main_context_iteration (gmain.c:3947)
==8911==    by 0x58BAC4C: g_application_run (gapplication.c:2401)
==8911==    by 0x12A117: main (gs-main.c:59)
==8911==  Address 0x15fb78b4 is 6,420 bytes inside a block of size 16,424 alloc'd
==8911==    at 0x4C31B25: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==8911==    by 0xC87C291: zalloc (wayland-private.h:234)
==8911==    by 0xC87C291: wl_connection_create (connection.c:166)
==8911==    by 0xC87AEDD: wl_display_connect_to_fd (wayland-client.c:972)
==8911==    by 0xC87B010: wl_display_connect (wayland-client.c:1024)
==8911==    by 0x6762513: _gdk_wayland_display_open (gdkdisplay-wayland.c:537)
==8911==    by 0x6705C12: gdk_display_manager_open_display (gdkdisplaymanager.c:472)
==8911==    by 0x5FEA0C9: gtk_init_check (gtkmain.c:1103)
==8911==    by 0x5FEA0F8: gtk_init (gtkmain.c:1160)
==8911==    by 0x5EC9089: gtk_application_startup (gtkapplication.c:293)
==8911==    by 0x13513D: gs_application_startup (gs-application.c:778)
==8911==    by 0x52C1F9C: g_closure_invoke (gclosure.c:804)
==8911==    by 0x52D4DAD: signal_emit_unlocked_R (gsignal.c:3565)
Comment 1 Pekka Paalanen 2017-10-25 06:15:53 UTC
Am I reading that report correctly that the uninitialized bytes are in a region allocated by calloc()?

Is that a mistake in the analysis, or do we first copy uninitialized data into the area and then get the warning only when trying to use them?
Comment 2 Daniel Stone 2018-06-04 08:49:49 UTC
Seb, if this still happens, could you please attach the output of running with 'WAYLAND_DEBUG=client'? That will at least give us a clue which Wayland requests have been made before this happens.
Comment 3 GitLab Migration User 2018-06-08 23:48:38 UTC
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

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