diff mbox series

[nf-next,1/4] ipvs: Update width of source for ip_vs_sync_con_options

Message ID 20230409-ipvs-cleanup-v1-1-98cdc242feb0@kernel.org (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series ipvs: Cleanups for v6.4 | expand

Checks

Context Check Description
netdev/series_format warning Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 20 this patch: 19
netdev/cc_maintainers warning 1 maintainers not CCed: horms@verge.net.au
netdev/build_clang success Errors and warnings before: 20 this patch: 18
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 20 this patch: 19
netdev/checkpatch warning CHECK: Alignment should match open parenthesis
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Simon Horman April 10, 2023, 9:42 a.m. UTC
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>
---
 include/net/ip_vs.h             | 6 ++++--
 net/netfilter/ipvs/ip_vs_sync.c | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 6d71a5ff52df..e20f1f92066d 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 4963fec815da..d4fe7bb4f853 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++;