41 lines
1.7 KiB
Diff
41 lines
1.7 KiB
Diff
From 4d0bed8c4690f7a2692474ef6a570bd99ef45ef1 Mon Sep 17 00:00:00 2001
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From: Philip Withnall <pwithnall@endlessos.org>
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Date: Thu, 15 Dec 2022 16:49:28 +0000
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Subject: [PATCH 2/2] gvariant: Propagate trust when getting a child of a
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serialised variant
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If a variant is trusted, that means all its children are trusted, so
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ensure that their checked offsets are set as such.
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This allows a lot of the offset table checks to be avoided when getting
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children from trusted serialised tuples, which speeds things up.
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No unit test is included because this is just a performance fix. If
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there are other slownesses, or regressions, in serialised `GVariant`
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performance, the fuzzing setup will catch them like it did this one.
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This change does reduce the time to run the oss-fuzz reproducer from 80s
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to about 0.7s on my machine.
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Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
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Fixes: #2841
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oss-fuzz#54314
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---
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glib/gvariant-core.c | 4 ++--
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1 file changed, 2 insertions(+), 2 deletions(-)
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--- a/glib/gvariant-core.c
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+++ b/glib/gvariant-core.c
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@@ -1196,8 +1196,8 @@ g_variant_get_child_value (GVariant *val
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child->contents.serialised.bytes =
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g_bytes_ref (value->contents.serialised.bytes);
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child->contents.serialised.data = s_child.data;
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- child->contents.serialised.ordered_offsets_up_to = s_child.ordered_offsets_up_to;
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- child->contents.serialised.checked_offsets_up_to = s_child.checked_offsets_up_to;
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+ child->contents.serialised.ordered_offsets_up_to = (value->state & STATE_TRUSTED) ? G_MAXSIZE : s_child.ordered_offsets_up_to;
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+ child->contents.serialised.checked_offsets_up_to = (value->state & STATE_TRUSTED) ? G_MAXSIZE : s_child.checked_offsets_up_to;
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return child;
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}
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