[PATCH] amd-xgbe: Avoid potential string truncation in name

From: Kees Cook
Date: Tue Dec 12 2023 - 17:13:20 EST


Build with W=1 were warning about a potential string truncation:

drivers/net/ethernet/amd/xgbe/xgbe-drv.c: In function 'xgbe_alloc_channels':
drivers/net/ethernet/amd/xgbe/xgbe-drv.c:211:73: warning: '%u' directive output may be truncated writing between 1 and 10 bytes into a region of size 8 [-Wformat-truncation=]
211 | snprintf(channel->name, sizeof(channel->name), "channel-%u", i);
| ^~
drivers/net/ethernet/amd/xgbe/xgbe-drv.c:211:64: note: directive argument in the range [0, 4294967294]
211 | snprintf(channel->name, sizeof(channel->name), "channel-%u", i);
| ^~~~~~~~~~~~
drivers/net/ethernet/amd/xgbe/xgbe-drv.c:211:17: note: 'snprintf' output between 10 and 19 bytes into a destination of size 16
211 | snprintf(channel->name, sizeof(channel->name), "channel-%u", i);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Increase the size of the "name" buffer to handle the full format range.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202312100937.ZPZCARhB-lkp@xxxxxxxxx/
Cc: Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
drivers/net/ethernet/amd/xgbe/xgbe.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe.h b/drivers/net/ethernet/amd/xgbe/xgbe.h
index ad136ed493ed..f01a1e566da6 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe.h
+++ b/drivers/net/ethernet/amd/xgbe/xgbe.h
@@ -495,7 +495,7 @@ struct xgbe_ring {
* a DMA channel.
*/
struct xgbe_channel {
- char name[16];
+ char name[20];

/* Address of private data area for device */
struct xgbe_prv_data *pdata;
--
2.34.1