From 9bbcdb07a53549ed072f03a88a5012e939a64c01 Mon Sep 17 00:00:00 2001 From: Chris Packham Date: Mon, 20 May 2019 15:45:36 +1200 Subject: tipc: Avoid copying bytes beyond the supplied data TLV_SET is called with a data pointer and a len parameter that tells us how many bytes are pointed to by data. When invoking memcpy() we need to careful to only copy len bytes. Previously we would copy TLV_LENGTH(len) bytes which would copy an extra 4 bytes past the end of the data pointer which newer GCC versions complain about. In file included from test.c:17: In function 'TLV_SET', inlined from 'test' at test.c:186:5: /usr/include/linux/tipc_config.h:317:3: warning: 'memcpy' forming offset [33, 36] is out of the bounds [0, 32] of object 'bearer_name' with type 'char[32]' [-Warray-bounds] memcpy(TLV_DATA(tlv_ptr), data, tlv_len); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ test.c: In function 'test': test.c::161:10: note: 'bearer_name' declared here char bearer_name[TIPC_MAX_BEARER_NAME]; ^~~~~~~~~~~ We still want to ensure any padding bytes at the end are initialised, do this with a explicit memset() rather than copy bytes past the end of data. Apply the same logic to TCM_SET. Signed-off-by: Chris Packham Signed-off-by: David S. Miller --- include/uapi/linux/tipc_config.h | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/uapi/linux/tipc_config.h b/include/uapi/linux/tipc_config.h index 4b2c93b1934c..4955e1a9f1bc 100644 --- a/include/uapi/linux/tipc_config.h +++ b/include/uapi/linux/tipc_config.h @@ -307,8 +307,10 @@ static inline int TLV_SET(void *tlv, __u16 type, void *data, __u16 len) tlv_ptr = (struct tlv_desc *)tlv; tlv_ptr->tlv_type = htons(type); tlv_ptr->tlv_len = htons(tlv_len); - if (len && data) - memcpy(TLV_DATA(tlv_ptr), data, tlv_len); + if (len && data) { + memcpy(TLV_DATA(tlv_ptr), data, len); + memset(TLV_DATA(tlv_ptr) + len, 0, TLV_SPACE(len) - tlv_len); + } return TLV_SPACE(len); } @@ -405,8 +407,10 @@ static inline int TCM_SET(void *msg, __u16 cmd, __u16 flags, tcm_hdr->tcm_len = htonl(msg_len); tcm_hdr->tcm_type = htons(cmd); tcm_hdr->tcm_flags = htons(flags); - if (data_len && data) + if (data_len && data) { memcpy(TCM_DATA(msg), data, data_len); + memset(TCM_DATA(msg) + data_len, 0, TCM_SPACE(data_len) - msg_len); + } return TCM_SPACE(data_len); } -- cgit v1.2.3-59-g8ed1b