From: Simon Horman horms@kernel.org
[ Upstream commit e3478c68f6704638d08f437cbc552ca5970c151a ]
In ip_vs_sync_conn_v0() copy is made to struct ip_vs_sync_conn_options. That structure looks like this:
struct ip_vs_sync_conn_options { struct ip_vs_seq in_seq; struct ip_vs_seq out_seq; };
The source of the copy is the in_seq field of struct ip_vs_conn. Whose type is struct ip_vs_seq. Thus we can see that the source - is not as wide as the amount of data copied, which is the width of struct ip_vs_sync_conn_option.
The copy is safe because the next field in is another struct ip_vs_seq. Make use of struct_group() to annotate this.
Flagged by gcc-13 as:
In file included from ./include/linux/string.h:254, from ./include/linux/bitmap.h:11, from ./include/linux/cpumask.h:12, from ./arch/x86/include/asm/paravirt.h:17, from ./arch/x86/include/asm/cpuid.h:62, from ./arch/x86/include/asm/processor.h:19, from ./arch/x86/include/asm/timex.h:5, from ./include/linux/timex.h:67, from ./include/linux/time32.h:13, from ./include/linux/time.h:60, from ./include/linux/stat.h:19, from ./include/linux/module.h:13, from net/netfilter/ipvs/ip_vs_sync.c:38: In function 'fortify_memcpy_chk', inlined from 'ip_vs_sync_conn_v0' at net/netfilter/ipvs/ip_vs_sync.c:606:3: ./include/linux/fortify-string.h:529:25: error: call to '__read_overflow2_field' declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Werror=attribute-warning] 529 | __read_overflow2_field(q_size_field, size); |
Compile tested only.
Signed-off-by: Simon Horman horms@kernel.org Reviewed-by: Horatiu Vultur horatiu.vultur@microchip.com Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/ip_vs.h | 6 ++++-- net/netfilter/ipvs/ip_vs_sync.c | 2 +- 2 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h index 6d71a5ff52dfd..e20f1f92066d1 100644 --- a/include/net/ip_vs.h +++ b/include/net/ip_vs.h @@ -630,8 +630,10 @@ struct ip_vs_conn { */ struct ip_vs_app *app; /* bound ip_vs_app object */ void *app_data; /* Application private data */ - struct ip_vs_seq in_seq; /* incoming seq. struct */ - struct ip_vs_seq out_seq; /* outgoing seq. struct */ + struct_group(sync_conn_opt, + struct ip_vs_seq in_seq; /* incoming seq. struct */ + struct ip_vs_seq out_seq; /* outgoing seq. struct */ + );
const struct ip_vs_pe *pe; char *pe_data; diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c index 4963fec815da3..d4fe7bb4f853a 100644 --- a/net/netfilter/ipvs/ip_vs_sync.c +++ b/net/netfilter/ipvs/ip_vs_sync.c @@ -603,7 +603,7 @@ static void ip_vs_sync_conn_v0(struct netns_ipvs *ipvs, struct ip_vs_conn *cp, if (cp->flags & IP_VS_CONN_F_SEQ_MASK) { struct ip_vs_sync_conn_options *opt = (struct ip_vs_sync_conn_options *)&s[1]; - memcpy(opt, &cp->in_seq, sizeof(*opt)); + memcpy(opt, &cp->sync_conn_opt, sizeof(*opt)); }
m->nr_conns++;