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module: Annotate struct module_notes_attrs with __counted_by

PATCH Applied Kees Cook 3 participants 3 messages Sep 22, 2023 – Sep 23, 2023 Module support

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Kees Cook

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#0 lore raw

PATCH 1/1 module: Annotate struct module_notes_attrs with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).

As found with Coccinelle[1], add __counted_by for struct module_notes_attrs.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc Luis Chamberlain <[email protected]>
Cc [email protected]
Signed-off-by Kees Cook <[email protected]>
---
 kernel/module/sysfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
kernel/module/sysfs.c +1 -1
index c921bf044050..d964167c6658 100644
@@ -143,7 +143,7 @@ static void remove_sect_attrs(struct module *mod)
 struct module_notes_attrs {
 	struct kobject *dir;
 	unsigned int notes;
-	struct bin_attribute attrs[];
+	struct bin_attribute attrs[] __counted_by(notes);
 };
 
 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
Signature · 1 line
2.34.1
maintainer Applied
#1 lore raw
Quoted 6 lines · Kees Cook

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).

Quoted 7 lines

As found with Coccinelle[1], add __counted_by for struct module_notes_attrs.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc Luis Chamberlain <[email protected]>
Cc [email protected]
Signed-off-by Kees Cook <[email protected]>

Thanks, applied and pushed!

Luis

Reviewed-by on v1 1/1
#2 lore raw
In reply to Kees Cook
Quoted 6 lines · Kees Cook

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).

Quoted 7 lines

As found with Coccinelle[1], add __counted_by for struct module_notes_attrs.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc Luis Chamberlain <[email protected]>
Cc [email protected]
Signed-off-by Kees Cook <[email protected]>
Reviewed-by Gustavo A. R. Silva <[email protected]>

Thanks
--
Gustavo

Quoted 21 lines
---
 kernel/module/sysfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
kernel/module/sysfs.c +1 -1
index c921bf044050..d964167c6658 100644
@@ -143,7 +143,7 @@ static void remove_sect_attrs(struct module *mod)
 struct module_notes_attrs {
 	struct kobject *dir;
 	unsigned int notes;
-	struct bin_attribute attrs[];
+	struct bin_attribute attrs[] __counted_by(notes);
 };
 
 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
Signature · 1 line
2.34.1