Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-23 20:51:44 +00:00
Code Issues Packages Projects Releases Wiki Activity

netfilter: conntrack: avoid gcc-10 zero-length-bounds warning

Browse Source 
gcc-10 warns around a suspicious access to an empty struct member:

net/netfilter/nf_conntrack_core.c: In function '__nf_conntrack_alloc':
net/netfilter/nf_conntrack_core.c:1522:9: warning: array subscript 0 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[0]'} [-Wzero-length-bounds]
 1522 |  memset(&ct->__nfct_init_offset[0], 0,
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from net/netfilter/nf_conntrack_core.c:37:
include/net/netfilter/nf_conntrack.h:90:5: note: while referencing '__nfct_init_offset'
   90 |  u8 __nfct_init_offset[0];
      |     ^~~~~~~~~~~~~~~~~~

The code is correct but a bit unusual. Rework it slightly in a way that
does not trigger the warning, using an empty struct instead of an empty
array. There are probably more elegant ways to do this, but this is the
smallest change.

Fixes: c41884ce05 ("netfilter: conntrack: avoid zeroing timer")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Arnd Bergmann 2020-04-30 23:30:48 +02:00 committed by Pablo Neira Ayuso
parent 3047211ca1
commit 2c407aca64
2 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/net/netfilter/nf_conntrack.h
View File

@ -87,7 +87,7 @@ struct nf_conn {
struct hlist_node nat_bysource;
#endif
/* all members below initialized via memset */
u8 __nfct_init_offset[0];
struct { } __nfct_init_offset;
/* If we were expected by an expectation, this will be it */
struct nf_conn *master;

4
net/netfilter/nf_conntrack_core.c
View File

@ -1519,9 +1519,9 @@ __nf_conntrack_alloc(struct net *net,
ct->status = 0;
ct->timeout = 0;
write_pnet(&ct->ct_net, net);
memset(&ct->__nfct_init_offset[0], 0,
memset(&ct->__nfct_init_offset, 0,
offsetof(struct nf_conn, proto) -
offsetof(struct nf_conn, __nfct_init_offset[0]));
offsetof(struct nf_conn, __nfct_init_offset));
nf_ct_zone_add(ct, zone);