If the user provides a kind value that is more than 5 bits, the
BTF_KIND_INFO macro would emit incorrect values for info (by clobbering
values of the kind flag).
Tested on x86_64-redhat-linux.
include/ChangeLog:
* btf.h (BTF_TYPE_INFO): Protect against user providing invalid
kind.
Signed-off-by: Will Hawkins <hawki...@obs.cr>
---
Notes:
I have a small out-of-tree test but was not sure whether a) it should
be included and/or b) where it should be included. If you would
like me to include it, please just let me know where it should
go!
include/btf.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/btf.h b/include/btf.h
index 3f45ffb0b6b..0c3e1a1cf51 100644
--- a/include/btf.h
+++ b/include/btf.h
@@ -82,7 +82,7 @@ struct btf_type
};
};
-/* The folloing macros access the information encoded in btf_type.info. */
+/* The following macros access the information encoded in btf_type.info. */
/* Type kind. See below. */
#define BTF_INFO_KIND(info) (((info) >> 24) & 0x1f)
/* Number of entries of variable length data following certain type kinds.
@@ -95,7 +95,7 @@ struct btf_type
/* Encoding for struct btf_type.info. */
#define BTF_TYPE_INFO(kind, kflag, vlen) \
- ((((kflag) ? 1 : 0 ) << 31) | ((kind) << 24) | ((vlen) & 0xffff))
+ ((((kflag) ? 1 : 0 ) << 31) | ((kind & 0x1f) << 24) | ((vlen) & 0xffff))
#define BTF_KIND_UNKN 0 /* Unknown or invalid. */
#define BTF_KIND_INT 1 /* Integer. */
--
2.45.2
