diff options
authorChris Packham <chris.packham@alliedtelesis.co.nz>2019-05-20 03:45:36 (GMT)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-06-04 05:59:43 (GMT)
commitb78931285473f7258ce7657b4feeff6ff6397b83 (patch)
parent34569012a1ca0fe326e393618cfcaadbce995147 (diff)
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 <chris.packham@alliedtelesis.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 7 insertions, 3 deletions
diff --git a/include/uapi/linux/tipc_config.h b/include/uapi/linux/tipc_config.h
index 4b2c93b..4955e1a 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);