FAILED: patch "[PATCH] randstruct: gcc-plugin: Fix attribute addition" failed to apply to 5.4-stable tree
The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x f39f18f3c3531aa802b58a20d39d96e82eb96c14 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025060528-osmosis-arose-1289@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f39f18f3c3531aa802b58a20d39d96e82eb96c14 Mon Sep 17 00:00:00 2001 From: Kees Cook kees@kernel.org Date: Fri, 30 May 2025 15:18:28 -0700 Subject: [PATCH] randstruct: gcc-plugin: Fix attribute addition
Based on changes in the 2021 public version of the randstruct out-of-tree GCC plugin[1], more carefully update the attributes on resulting decls, to avoid tripping checks in GCC 15's comptypes_check_enum_int() when it has been configured with "--enable-checking=misc":
arch/arm64/kernel/kexec_image.c:132:14: internal compiler error: in comptypes_check_enum_int, at c/c-typeck.cc:1519 132 | const struct kexec_file_ops kexec_image_ops = { | ^~~~~~~~~~~~~~ internal_error(char const*, ...), at gcc/gcc/diagnostic-global-context.cc:517 fancy_abort(char const*, int, char const*), at gcc/gcc/diagnostic.cc:1803 comptypes_check_enum_int(tree_node*, tree_node*, bool*), at gcc/gcc/c/c-typeck.cc:1519 ...
Link: https://archive.org/download/grsecurity/grsecurity-3.1-5.10.41-202105280954.... [1] Reported-by: Thiago Jung Bauermann thiago.bauermann@linaro.org Closes: https://github.com/KSPP/linux/issues/367 Closes: https://lore.kernel.org/lkml/20250530000646.104457-1-thiago.bauermann@linaro... Reported-by: Ingo Saitz ingo@hannover.ccc.de Closes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1104745 Fixes: 313dd1b62921 ("gcc-plugins: Add the randstruct plugin") Tested-by: Thiago Jung Bauermann thiago.bauermann@linaro.org Link: https://lore.kernel.org/r/20250530221824.work.623-kees@kernel.org Signed-off-by: Kees Cook kees@kernel.org
diff --git a/scripts/gcc-plugins/gcc-common.h b/scripts/gcc-plugins/gcc-common.h index 3222c1070444..ef12c8f929ed 100644 --- a/scripts/gcc-plugins/gcc-common.h +++ b/scripts/gcc-plugins/gcc-common.h @@ -123,6 +123,38 @@ static inline tree build_const_char_string(int len, const char *str) return cstr; }
+static inline void __add_type_attr(tree type, const char *attr, tree args) +{ + tree oldattr; + + if (type == NULL_TREE) + return; + oldattr = lookup_attribute(attr, TYPE_ATTRIBUTES(type)); + if (oldattr != NULL_TREE) { + gcc_assert(TREE_VALUE(oldattr) == args || TREE_VALUE(TREE_VALUE(oldattr)) == TREE_VALUE(args)); + return; + } + + TYPE_ATTRIBUTES(type) = copy_list(TYPE_ATTRIBUTES(type)); + TYPE_ATTRIBUTES(type) = tree_cons(get_identifier(attr), args, TYPE_ATTRIBUTES(type)); +} + +static inline void add_type_attr(tree type, const char *attr, tree args) +{ + tree main_variant = TYPE_MAIN_VARIANT(type); + + __add_type_attr(TYPE_CANONICAL(type), attr, args); + __add_type_attr(TYPE_CANONICAL(main_variant), attr, args); + __add_type_attr(main_variant, attr, args); + + for (type = TYPE_NEXT_VARIANT(main_variant); type; type = TYPE_NEXT_VARIANT(type)) { + if (!lookup_attribute(attr, TYPE_ATTRIBUTES(type))) + TYPE_ATTRIBUTES(type) = TYPE_ATTRIBUTES(main_variant); + + __add_type_attr(TYPE_CANONICAL(type), attr, args); + } +} + #define PASS_INFO(NAME, REF, ID, POS) \ struct register_pass_info NAME##_pass_info = { \ .pass = make_##NAME##_pass(), \ diff --git a/scripts/gcc-plugins/randomize_layout_plugin.c b/scripts/gcc-plugins/randomize_layout_plugin.c index 971a1908a8cc..ff65a4f87f24 100644 --- a/scripts/gcc-plugins/randomize_layout_plugin.c +++ b/scripts/gcc-plugins/randomize_layout_plugin.c @@ -73,6 +73,9 @@ static tree handle_randomize_layout_attr(tree *node, tree name, tree args, int f
if (TYPE_P(*node)) { type = *node; + } else if (TREE_CODE(*node) == FIELD_DECL) { + *no_add_attrs = false; + return NULL_TREE; } else { gcc_assert(TREE_CODE(*node) == TYPE_DECL); type = TREE_TYPE(*node); @@ -348,15 +351,14 @@ static int relayout_struct(tree type) TREE_CHAIN(newtree[i]) = newtree[i+1]; TREE_CHAIN(newtree[num_fields - 1]) = NULL_TREE;
+ add_type_attr(type, "randomize_performed", NULL_TREE); + add_type_attr(type, "designated_init", NULL_TREE); + if (has_flexarray) + add_type_attr(type, "has_flexarray", NULL_TREE); + main_variant = TYPE_MAIN_VARIANT(type); - for (variant = main_variant; variant; variant = TYPE_NEXT_VARIANT(variant)) { + for (variant = main_variant; variant; variant = TYPE_NEXT_VARIANT(variant)) TYPE_FIELDS(variant) = newtree[0]; - TYPE_ATTRIBUTES(variant) = copy_list(TYPE_ATTRIBUTES(variant)); - TYPE_ATTRIBUTES(variant) = tree_cons(get_identifier("randomize_performed"), NULL_TREE, TYPE_ATTRIBUTES(variant)); - TYPE_ATTRIBUTES(variant) = tree_cons(get_identifier("designated_init"), NULL_TREE, TYPE_ATTRIBUTES(variant)); - if (has_flexarray) - TYPE_ATTRIBUTES(type) = tree_cons(get_identifier("has_flexarray"), NULL_TREE, TYPE_ATTRIBUTES(type)); - }
/* * force a re-layout of the main variant @@ -424,10 +426,8 @@ static void randomize_type(tree type) if (lookup_attribute("randomize_layout", TYPE_ATTRIBUTES(TYPE_MAIN_VARIANT(type))) || is_pure_ops_struct(type)) relayout_struct(type);
- for (variant = TYPE_MAIN_VARIANT(type); variant; variant = TYPE_NEXT_VARIANT(variant)) { - TYPE_ATTRIBUTES(type) = copy_list(TYPE_ATTRIBUTES(type)); - TYPE_ATTRIBUTES(type) = tree_cons(get_identifier("randomize_considered"), NULL_TREE, TYPE_ATTRIBUTES(type)); - } + add_type_attr(type, "randomize_considered", NULL_TREE); + #ifdef __DEBUG_PLUGIN fprintf(stderr, "Marking randomize_considered on struct %s\n", ORIG_TYPE_NAME(type)); #ifdef __DEBUG_VERBOSE
From: Kees Cook kees@kernel.org
[ Upstream commit e136a4062174a9a8d1c1447ca040ea81accfa6a8 ]
When building the randomized replacement tree of struct members, the randstruct GCC plugin would insert, as the first member, a 0-sized void member. This appears as though it was done to catch non-designated ("unnamed") static initializers, which wouldn't be stable since they depend on the original struct layout order.
This was accomplished by having the side-effect of the "void member" tripping an assert in GCC internals (count_type_elements) if the member list ever needed to be counted (e.g. for figuring out the order of members during a non-designated initialization), which would catch impossible type (void) in the struct:
security/landlock/fs.c: In function ‘hook_file_ioctl_common’: security/landlock/fs.c:1745:61: internal compiler error: in count_type_elements, at expr.cc:7075 1745 | .u.op = &(struct lsm_ioctlop_audit) { | ^
static HOST_WIDE_INT count_type_elements (const_tree type, bool for_ctor_p) { switch (TREE_CODE (type)) ... case VOID_TYPE: default: gcc_unreachable (); } }
However this is a redundant safety measure since randstruct uses the __designated_initializer attribute both internally and within the __randomized_layout attribute macro so that this would be enforced by the compiler directly even when randstruct was not enabled (via -Wdesignated-init).
A recent change in Landlock ended up tripping the same member counting routine when using a full-struct copy initializer as part of an anonymous initializer. This, however, is a false positive as the initializer is copying between identical structs (and hence identical layouts). The "path" member is "struct path", a randomized struct, and is being copied to from another "struct path", the "f_path" member:
landlock_log_denial(landlock_cred(file->f_cred), &(struct landlock_request) { .type = LANDLOCK_REQUEST_FS_ACCESS, .audit = { .type = LSM_AUDIT_DATA_IOCTL_OP, .u.op = &(struct lsm_ioctlop_audit) { .path = file->f_path, .cmd = cmd, }, }, ...
As can be seen with the coming randstruct KUnit test, there appears to be no behavioral problems with this kind of initialization when the void member is removed from the randstruct GCC plugin, so remove it.
Reported-by: "Dr. David Alan Gilbert" linux@treblig.org Closes: https://lore.kernel.org/lkml/Z_PRaKx7q70MKgCA@gallifrey/ Reported-by: Mark Brown broonie@kernel.org Closes: https://lore.kernel.org/lkml/20250407-kbuild-disable-gcc-plugins-v1-1-5d46ae... Reported-by: WangYuli wangyuli@uniontech.com Closes: https://lore.kernel.org/lkml/337D5D4887277B27+3c677db3-a8b9-47f0-93a4-780935... Fixes: 313dd1b62921 ("gcc-plugins: Add the randstruct plugin") Signed-off-by: Kees Cook kees@kernel.org Stable-dep-of: f39f18f3c353 ("randstruct: gcc-plugin: Fix attribute addition") Signed-off-by: Sasha Levin sashal@kernel.org --- scripts/gcc-plugins/randomize_layout_plugin.c | 18 +----------------- 1 file changed, 1 insertion(+), 17 deletions(-)
diff --git a/scripts/gcc-plugins/randomize_layout_plugin.c b/scripts/gcc-plugins/randomize_layout_plugin.c index c7ff92b4189cb..a5aea51ecca99 100644 --- a/scripts/gcc-plugins/randomize_layout_plugin.c +++ b/scripts/gcc-plugins/randomize_layout_plugin.c @@ -377,29 +377,13 @@ static int relayout_struct(tree type)
shuffle(type, (tree *)newtree, shuffle_length);
- /* - * set up a bogus anonymous struct field designed to error out on unnamed struct initializers - * as gcc provides no other way to detect such code - */ - list = make_node(FIELD_DECL); - TREE_CHAIN(list) = newtree[0]; - TREE_TYPE(list) = void_type_node; - DECL_SIZE(list) = bitsize_zero_node; - DECL_NONADDRESSABLE_P(list) = 1; - DECL_FIELD_BIT_OFFSET(list) = bitsize_zero_node; - DECL_SIZE_UNIT(list) = size_zero_node; - DECL_FIELD_OFFSET(list) = size_zero_node; - DECL_CONTEXT(list) = type; - // to satisfy the constify plugin - TREE_READONLY(list) = 1; - for (i = 0; i < num_fields - 1; i++) TREE_CHAIN(newtree[i]) = newtree[i+1]; TREE_CHAIN(newtree[num_fields - 1]) = NULL_TREE;
main_variant = TYPE_MAIN_VARIANT(type); for (variant = main_variant; variant; variant = TYPE_NEXT_VARIANT(variant)) { - TYPE_FIELDS(variant) = list; + TYPE_FIELDS(variant) = newtree[0]; TYPE_ATTRIBUTES(variant) = copy_list(TYPE_ATTRIBUTES(variant)); TYPE_ATTRIBUTES(variant) = tree_cons(get_identifier("randomize_performed"), NULL_TREE, TYPE_ATTRIBUTES(variant)); TYPE_ATTRIBUTES(variant) = tree_cons(get_identifier("designated_init"), NULL_TREE, TYPE_ATTRIBUTES(variant));
From: Kees Cook kees@kernel.org
[ Upstream commit f39f18f3c3531aa802b58a20d39d96e82eb96c14 ]
Based on changes in the 2021 public version of the randstruct out-of-tree GCC plugin[1], more carefully update the attributes on resulting decls, to avoid tripping checks in GCC 15's comptypes_check_enum_int() when it has been configured with "--enable-checking=misc":
arch/arm64/kernel/kexec_image.c:132:14: internal compiler error: in comptypes_check_enum_int, at c/c-typeck.cc:1519 132 | const struct kexec_file_ops kexec_image_ops = { | ^~~~~~~~~~~~~~ internal_error(char const*, ...), at gcc/gcc/diagnostic-global-context.cc:517 fancy_abort(char const*, int, char const*), at gcc/gcc/diagnostic.cc:1803 comptypes_check_enum_int(tree_node*, tree_node*, bool*), at gcc/gcc/c/c-typeck.cc:1519 ...
Link: https://archive.org/download/grsecurity/grsecurity-3.1-5.10.41-202105280954.... [1] Reported-by: Thiago Jung Bauermann thiago.bauermann@linaro.org Closes: https://github.com/KSPP/linux/issues/367 Closes: https://lore.kernel.org/lkml/20250530000646.104457-1-thiago.bauermann@linaro... Reported-by: Ingo Saitz ingo@hannover.ccc.de Closes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1104745 Fixes: 313dd1b62921 ("gcc-plugins: Add the randstruct plugin") Tested-by: Thiago Jung Bauermann thiago.bauermann@linaro.org Link: https://lore.kernel.org/r/20250530221824.work.623-kees@kernel.org Signed-off-by: Kees Cook kees@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- scripts/gcc-plugins/gcc-common.h | 32 +++++++++++++++++++ scripts/gcc-plugins/randomize_layout_plugin.c | 22 ++++++------- 2 files changed, 43 insertions(+), 11 deletions(-)
diff --git a/scripts/gcc-plugins/gcc-common.h b/scripts/gcc-plugins/gcc-common.h index 0907ab19202a1..6ec887ae71b64 100644 --- a/scripts/gcc-plugins/gcc-common.h +++ b/scripts/gcc-plugins/gcc-common.h @@ -182,6 +182,38 @@ static inline tree build_const_char_string(int len, const char *str) return cstr; }
+static inline void __add_type_attr(tree type, const char *attr, tree args) +{ + tree oldattr; + + if (type == NULL_TREE) + return; + oldattr = lookup_attribute(attr, TYPE_ATTRIBUTES(type)); + if (oldattr != NULL_TREE) { + gcc_assert(TREE_VALUE(oldattr) == args || TREE_VALUE(TREE_VALUE(oldattr)) == TREE_VALUE(args)); + return; + } + + TYPE_ATTRIBUTES(type) = copy_list(TYPE_ATTRIBUTES(type)); + TYPE_ATTRIBUTES(type) = tree_cons(get_identifier(attr), args, TYPE_ATTRIBUTES(type)); +} + +static inline void add_type_attr(tree type, const char *attr, tree args) +{ + tree main_variant = TYPE_MAIN_VARIANT(type); + + __add_type_attr(TYPE_CANONICAL(type), attr, args); + __add_type_attr(TYPE_CANONICAL(main_variant), attr, args); + __add_type_attr(main_variant, attr, args); + + for (type = TYPE_NEXT_VARIANT(main_variant); type; type = TYPE_NEXT_VARIANT(type)) { + if (!lookup_attribute(attr, TYPE_ATTRIBUTES(type))) + TYPE_ATTRIBUTES(type) = TYPE_ATTRIBUTES(main_variant); + + __add_type_attr(TYPE_CANONICAL(type), attr, args); + } +} + #define PASS_INFO(NAME, REF, ID, POS) \ struct register_pass_info NAME##_pass_info = { \ .pass = make_##NAME##_pass(), \ diff --git a/scripts/gcc-plugins/randomize_layout_plugin.c b/scripts/gcc-plugins/randomize_layout_plugin.c index a5aea51ecca99..472427f169a4a 100644 --- a/scripts/gcc-plugins/randomize_layout_plugin.c +++ b/scripts/gcc-plugins/randomize_layout_plugin.c @@ -95,6 +95,9 @@ static tree handle_randomize_layout_attr(tree *node, tree name, tree args, int f
if (TYPE_P(*node)) { type = *node; + } else if (TREE_CODE(*node) == FIELD_DECL) { + *no_add_attrs = false; + return NULL_TREE; } else { gcc_assert(TREE_CODE(*node) == TYPE_DECL); type = TREE_TYPE(*node); @@ -381,15 +384,14 @@ static int relayout_struct(tree type) TREE_CHAIN(newtree[i]) = newtree[i+1]; TREE_CHAIN(newtree[num_fields - 1]) = NULL_TREE;
+ add_type_attr(type, "randomize_performed", NULL_TREE); + add_type_attr(type, "designated_init", NULL_TREE); + if (has_flexarray) + add_type_attr(type, "has_flexarray", NULL_TREE); + main_variant = TYPE_MAIN_VARIANT(type); - for (variant = main_variant; variant; variant = TYPE_NEXT_VARIANT(variant)) { + for (variant = main_variant; variant; variant = TYPE_NEXT_VARIANT(variant)) TYPE_FIELDS(variant) = newtree[0]; - TYPE_ATTRIBUTES(variant) = copy_list(TYPE_ATTRIBUTES(variant)); - TYPE_ATTRIBUTES(variant) = tree_cons(get_identifier("randomize_performed"), NULL_TREE, TYPE_ATTRIBUTES(variant)); - TYPE_ATTRIBUTES(variant) = tree_cons(get_identifier("designated_init"), NULL_TREE, TYPE_ATTRIBUTES(variant)); - if (has_flexarray) - TYPE_ATTRIBUTES(type) = tree_cons(get_identifier("has_flexarray"), NULL_TREE, TYPE_ATTRIBUTES(type)); - }
/* * force a re-layout of the main variant @@ -457,10 +459,8 @@ static void randomize_type(tree type) if (lookup_attribute("randomize_layout", TYPE_ATTRIBUTES(TYPE_MAIN_VARIANT(type))) || is_pure_ops_struct(type)) relayout_struct(type);
- for (variant = TYPE_MAIN_VARIANT(type); variant; variant = TYPE_NEXT_VARIANT(variant)) { - TYPE_ATTRIBUTES(type) = copy_list(TYPE_ATTRIBUTES(type)); - TYPE_ATTRIBUTES(type) = tree_cons(get_identifier("randomize_considered"), NULL_TREE, TYPE_ATTRIBUTES(type)); - } + add_type_attr(type, "randomize_considered", NULL_TREE); + #ifdef __DEBUG_PLUGIN fprintf(stderr, "Marking randomize_considered on struct %s\n", ORIG_TYPE_NAME(type)); #ifdef __DEBUG_VERBOSE
linux-stable-mirror@lists.linaro.org
-
gregkh＠linuxfoundation.org -
Sasha Levin