diff options
Diffstat (limited to 'meta/recipes-core/glib-2.0/glib-2.0/CVE-2023-32665-0003.patch')
| -rw-r--r-- | meta/recipes-core/glib-2.0/glib-2.0/CVE-2023-32665-0003.patch | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/meta/recipes-core/glib-2.0/glib-2.0/CVE-2023-32665-0003.patch b/meta/recipes-core/glib-2.0/glib-2.0/CVE-2023-32665-0003.patch new file mode 100644 index 0000000000..e361cc7aad --- /dev/null +++ b/meta/recipes-core/glib-2.0/glib-2.0/CVE-2023-32665-0003.patch @@ -0,0 +1,417 @@ +From ade71fb544391b2e33e1859645726bfee0d5eaaf Mon Sep 17 00:00:00 2001 +From: William Manley <will@stb-tester.com> +Date: Wed, 16 Aug 2023 03:12:21 +0000 +Subject: [PATCH] gvariant: Don't allow child elements to overlap with each + other + +If different elements of a variable sized array can overlap with each +other then we can cause a `GVariant` to normalise to a much larger type. + +This commit changes the behaviour of `GVariant` with non-normal form data. If +an invalid frame offset is found all subsequent elements are given their +default value. + +When retrieving an element at index `n` we scan the frame offsets up to index +`n` and if they are not in order we return an element with the default value +for that type. This guarantees that elements don't overlap with each +other. We remember the offset we've scanned up to so we don't need to +repeat this work on subsequent accesses. We skip these checks for trusted +data. + +Unfortunately this makes random access of untrusted data O(n) — at least +on first access. It doesn't affect the algorithmic complexity of accessing +elements in order, such as when using the `GVariantIter` interface. Also: +the cost of validation will be amortised as the `GVariant` instance is +continued to be used. + +I've implemented this with 4 different functions, 1 for each element size, +rather than looping calling `gvs_read_unaligned_le` in the hope that the +compiler will find it easy to optimise and should produce fairly tight +code. + +Fixes: #2121 + +CVE: CVE-2023-32665 +Upstream-Status: Backport from [https://gitlab.gnome.org/GNOME/glib/-/commit/ade71fb544391b2e33e1859645726bfee0d5eaaf] +Signed-off-by: Siddharth Doshi <sdoshi@mvista.com> +--- + glib/gvariant-core.c | 35 ++++++++++++++++ + glib/gvariant-serialiser.c | 86 ++++++++++++++++++++++++++++++++++++-- + glib/gvariant-serialiser.h | 8 ++++ + glib/tests/gvariant.c | 45 ++++++++++++++++++++ + 4 files changed, 171 insertions(+), 3 deletions(-) + +diff --git a/glib/gvariant-core.c b/glib/gvariant-core.c +index aa0e0a0..9b51e15 100644 +--- a/glib/gvariant-core.c ++++ b/glib/gvariant-core.c +@@ -65,6 +65,7 @@ struct _GVariant + { + GBytes *bytes; + gconstpointer data; ++ gsize ordered_offsets_up_to; + } serialised; + + struct +@@ -162,6 +163,24 @@ struct _GVariant + * if .data pointed to the appropriate number of nul + * bytes. + * ++ * .ordered_offsets_up_to: If ordered_offsets_up_to == n this means that all ++ * the frame offsets up to and including the frame ++ * offset determining the end of element n are in ++ * order. This guarantees that the bytes of element ++ * n don't overlap with any previous element. ++ * ++ * For trusted data this is set to G_MAXSIZE and we ++ * don't check that the frame offsets are in order. ++ * ++ * Note: This doesn't imply the offsets are good in ++ * any way apart from their ordering. In particular ++ * offsets may be out of bounds for this value or ++ * may imply that the data overlaps the frame ++ * offsets themselves. ++ * ++ * This field is only relevant for arrays of non ++ * fixed width types. ++ * + * .tree: Only valid when the instance is in tree form. + * + * Note that accesses from other threads could result in +@@ -365,6 +384,7 @@ g_variant_to_serialised (GVariant *value) + (gpointer) value->contents.serialised.data, + value->size, + value->depth, ++ value->contents.serialised.ordered_offsets_up_to, + }; + return serialised; + } +@@ -396,6 +416,7 @@ g_variant_serialise (GVariant *value, + serialised.size = value->size; + serialised.data = data; + serialised.depth = value->depth; ++ serialised.ordered_offsets_up_to = 0; + + children = (gpointer *) value->contents.tree.children; + n_children = value->contents.tree.n_children; +@@ -439,6 +460,15 @@ g_variant_fill_gvs (GVariantSerialised *serialised, + g_assert (serialised->size == value->size); + serialised->depth = value->depth; + ++ if (value->state & STATE_SERIALISED) ++ { ++ serialised->ordered_offsets_up_to = value->contents.serialised.ordered_offsets_up_to; ++ } ++ else ++ { ++ serialised->ordered_offsets_up_to = 0; ++ } ++ + if (serialised->data) + /* g_variant_store() is a public API, so it + * it will reacquire the lock if it needs to. +@@ -481,6 +511,7 @@ g_variant_ensure_serialised (GVariant *value) + bytes = g_bytes_new_take (data, value->size); + value->contents.serialised.data = g_bytes_get_data (bytes, NULL); + value->contents.serialised.bytes = bytes; ++ value->contents.serialised.ordered_offsets_up_to = G_MAXSIZE; + value->state |= STATE_SERIALISED; + } + } +@@ -561,6 +592,7 @@ g_variant_new_from_bytes (const GVariantType *type, + serialised.type_info = value->type_info; + serialised.data = (guchar *) g_bytes_get_data (bytes, &serialised.size); + serialised.depth = 0; ++ serialised.ordered_offsets_up_to = trusted ? G_MAXSIZE : 0; + + if (!g_variant_serialised_check (serialised)) + { +@@ -610,6 +642,8 @@ g_variant_new_from_bytes (const GVariantType *type, + value->contents.serialised.data = g_bytes_get_data (bytes, &value->size); + } + ++ value->contents.serialised.ordered_offsets_up_to = trusted ? G_MAXSIZE : 0; ++ + g_clear_pointer (&owned_bytes, g_bytes_unref); + + return value; +@@ -1108,6 +1142,7 @@ g_variant_get_child_value (GVariant *value, + child->contents.serialised.bytes = + g_bytes_ref (value->contents.serialised.bytes); + child->contents.serialised.data = s_child.data; ++ child->contents.serialised.ordered_offsets_up_to = s_child.ordered_offsets_up_to; + + return child; + } +diff --git a/glib/gvariant-serialiser.c b/glib/gvariant-serialiser.c +index c7c2114..fe0b1a4 100644 +--- a/glib/gvariant-serialiser.c ++++ b/glib/gvariant-serialiser.c +@@ -1,6 +1,7 @@ + /* + * Copyright © 2007, 2008 Ryan Lortie + * Copyright © 2010 Codethink Limited ++ * Copyright © 2020 William Manley + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public +@@ -264,6 +265,7 @@ gvs_fixed_sized_maybe_get_child (GVariantSerialised value, + value.type_info = g_variant_type_info_element (value.type_info); + g_variant_type_info_ref (value.type_info); + value.depth++; ++ value.ordered_offsets_up_to = 0; + + return value; + } +@@ -295,7 +297,7 @@ gvs_fixed_sized_maybe_serialise (GVariantSerialised value, + { + if (n_children) + { +- GVariantSerialised child = { NULL, value.data, value.size, value.depth + 1 }; ++ GVariantSerialised child = { NULL, value.data, value.size, value.depth + 1, 0 }; + + gvs_filler (&child, children[0]); + } +@@ -317,6 +319,7 @@ gvs_fixed_sized_maybe_is_normal (GVariantSerialised value) + /* proper element size: "Just". recurse to the child. */ + value.type_info = g_variant_type_info_element (value.type_info); + value.depth++; ++ value.ordered_offsets_up_to = 0; + + return g_variant_serialised_is_normal (value); + } +@@ -358,6 +361,7 @@ gvs_variable_sized_maybe_get_child (GVariantSerialised value, + value.data = NULL; + + value.depth++; ++ value.ordered_offsets_up_to = 0; + + return value; + } +@@ -388,7 +392,7 @@ gvs_variable_sized_maybe_serialise (GVariantSerialised value, + { + if (n_children) + { +- GVariantSerialised child = { NULL, value.data, value.size - 1, value.depth + 1 }; ++ GVariantSerialised child = { NULL, value.data, value.size - 1, value.depth + 1, 0 }; + + /* write the data for the child. */ + gvs_filler (&child, children[0]); +@@ -408,6 +412,7 @@ gvs_variable_sized_maybe_is_normal (GVariantSerialised value) + value.type_info = g_variant_type_info_element (value.type_info); + value.size--; + value.depth++; ++ value.ordered_offsets_up_to = 0; + + return g_variant_serialised_is_normal (value); + } +@@ -691,6 +696,32 @@ gvs_variable_sized_array_n_children (GVariantSerialised value) + return gvs_variable_sized_array_get_frame_offsets (value).length; + } + ++/* Find the index of the first out-of-order element in @data, assuming that ++ * @data is an array of elements of given @type, starting at index @start and ++ * containing a further @len-@start elements. */ ++#define DEFINE_FIND_UNORDERED(type) \ ++ static gsize \ ++ find_unordered_##type (const guint8 *data, gsize start, gsize len) \ ++ { \ ++ gsize off; \ ++ type current, previous; \ ++ \ ++ memcpy (&previous, data + start * sizeof (current), sizeof (current)); \ ++ for (off = (start + 1) * sizeof (current); off < len * sizeof (current); off += sizeof (current)) \ ++ { \ ++ memcpy (¤t, data + off, sizeof (current)); \ ++ if (current < previous) \ ++ break; \ ++ previous = current; \ ++ } \ ++ return off / sizeof (current) - 1; \ ++ } ++ ++DEFINE_FIND_UNORDERED (guint8); ++DEFINE_FIND_UNORDERED (guint16); ++DEFINE_FIND_UNORDERED (guint32); ++DEFINE_FIND_UNORDERED (guint64); ++ + static GVariantSerialised + gvs_variable_sized_array_get_child (GVariantSerialised value, + gsize index_) +@@ -706,6 +737,49 @@ gvs_variable_sized_array_get_child (GVariantSerialised value, + g_variant_type_info_ref (child.type_info); + child.depth = value.depth + 1; + ++ /* If the requested @index_ is beyond the set of indices whose framing offsets ++ * have been checked, check the remaining offsets to see whether they’re ++ * normal (in order, no overlapping array elements). */ ++ if (index_ > value.ordered_offsets_up_to) ++ { ++ switch (offsets.offset_size) ++ { ++ case 1: ++ { ++ value.ordered_offsets_up_to = find_unordered_guint8 ( ++ offsets.array, value.ordered_offsets_up_to, index_ + 1); ++ break; ++ } ++ case 2: ++ { ++ value.ordered_offsets_up_to = find_unordered_guint16 ( ++ offsets.array, value.ordered_offsets_up_to, index_ + 1); ++ break; ++ } ++ case 4: ++ { ++ value.ordered_offsets_up_to = find_unordered_guint32 ( ++ offsets.array, value.ordered_offsets_up_to, index_ + 1); ++ break; ++ } ++ case 8: ++ { ++ value.ordered_offsets_up_to = find_unordered_guint64 ( ++ offsets.array, value.ordered_offsets_up_to, index_ + 1); ++ break; ++ } ++ default: ++ /* gvs_get_offset_size() only returns maximum 8 */ ++ g_assert_not_reached (); ++ } ++ } ++ ++ if (index_ > value.ordered_offsets_up_to) ++ { ++ /* Offsets are invalid somewhere, so return an empty child. */ ++ return child; ++ } ++ + if (index_ > 0) + { + guint alignment; +@@ -840,6 +914,9 @@ gvs_variable_sized_array_is_normal (GVariantSerialised value) + + g_assert (offset == offsets.data_size); + ++ /* All offsets have now been checked. */ ++ value.ordered_offsets_up_to = G_MAXSIZE; ++ + return TRUE; + } + +@@ -1072,7 +1149,7 @@ gvs_tuple_is_normal (GVariantSerialised value) + for (i = 0; i < length; i++) + { + const GVariantMemberInfo *member_info; +- GVariantSerialised child; ++ GVariantSerialised child = { 0, }; + gsize fixed_size; + guint alignment; + gsize end; +@@ -1132,6 +1209,9 @@ gvs_tuple_is_normal (GVariantSerialised value) + offset = end; + } + ++ /* All element bounds have been checked above. */ ++ value.ordered_offsets_up_to = G_MAXSIZE; ++ + { + gsize fixed_size; + guint alignment; +diff --git a/glib/gvariant-serialiser.h b/glib/gvariant-serialiser.h +index 81343e9..99d18ef 100644 +--- a/glib/gvariant-serialiser.h ++++ b/glib/gvariant-serialiser.h +@@ -29,6 +29,14 @@ typedef struct + guchar *data; + gsize size; + gsize depth; /* same semantics as GVariant.depth */ ++ /* If ordered_offsets_up_to == n this means that all the frame offsets up to and ++ * including the frame offset determining the end of element n are in order. ++ * This guarantees that the bytes of element n don't overlap with any previous ++ * element. ++ * ++ * This is both read and set by g_variant_serialised_get_child for arrays of ++ * non-fixed-width types */ ++ gsize ordered_offsets_up_to; + } GVariantSerialised; + + /* deserialisation */ +diff --git a/glib/tests/gvariant.c b/glib/tests/gvariant.c +index 0e5ec8e..967e9a1 100644 +--- a/glib/tests/gvariant.c ++++ b/glib/tests/gvariant.c +@@ -1,5 +1,6 @@ + /* + * Copyright © 2010 Codethink Limited ++ * Copyright © 2020 William Manley + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public +@@ -1283,6 +1284,7 @@ random_instance_filler (GVariantSerialised *serialised, + serialised->size = instance->size; + + serialised->depth = 0; ++ serialised->ordered_offsets_up_to = 0; + + g_assert_true (serialised->type_info == instance->type_info); + g_assert_cmpuint (serialised->size, ==, instance->size); +@@ -5039,6 +5041,47 @@ test_normal_checking_array_offsets (void) + g_variant_unref (variant); + } + ++/* This is a regression test that we can't have non-normal values that take up ++ * significantly more space than the normal equivalent, by specifying the ++ * offset table entries so that array elements overlap. ++ * ++ * See https://gitlab.gnome.org/GNOME/glib/-/issues/2121#note_832242 */ ++static void ++test_normal_checking_array_offsets2 (void) ++{ ++ const guint8 data[] = { ++ 'h', 'i', '\0', ++ 0x03, 0x00, 0x03, ++ 0x06, 0x00, 0x06, ++ 0x09, 0x00, 0x09, ++ 0x0c, 0x00, 0x0c, ++ 0x0f, 0x00, 0x0f, ++ 0x12, 0x00, 0x12, ++ 0x15, 0x00, 0x15, ++ }; ++ gsize size = sizeof (data); ++ const GVariantType *aaaaaaas = G_VARIANT_TYPE ("aaaaaaas"); ++ GVariant *variant = NULL; ++ GVariant *normal_variant = NULL; ++ GVariant *expected = NULL; ++ ++ variant = g_variant_new_from_data (aaaaaaas, data, size, FALSE, NULL, NULL); ++ g_assert_nonnull (variant); ++ ++ normal_variant = g_variant_get_normal_form (variant); ++ g_assert_nonnull (normal_variant); ++ g_assert_cmpuint (g_variant_get_size (normal_variant), <=, size * 2); ++ ++ expected = g_variant_new_parsed ( ++ "[[[[[[['hi', '', ''], [], []], [], []], [], []], [], []], [], []], [], []]"); ++ g_assert_cmpvariant (expected, variant); ++ g_assert_cmpvariant (expected, normal_variant); ++ ++ g_variant_unref (expected); ++ g_variant_unref (normal_variant); ++ g_variant_unref (variant); ++} ++ + /* Test that a tuple with invalidly large values in its offset table is + * normalised successfully without looping infinitely. */ + static void +@@ -5206,6 +5249,8 @@ main (int argc, char **argv) + test_normal_checking_tuples); + g_test_add_func ("/gvariant/normal-checking/array-offsets", + test_normal_checking_array_offsets); ++ g_test_add_func ("/gvariant/normal-checking/array-offsets2", ++ test_normal_checking_array_offsets2); + g_test_add_func ("/gvariant/normal-checking/tuple-offsets", + test_normal_checking_tuple_offsets); + g_test_add_func ("/gvariant/normal-checking/empty-object-path", +-- +2.24.4 + |