[PATCH][V2] e1000: avoid null pointer dereference on invalid stat type
From: Colin King <hidden>
Date: 2017-09-22 13:41:38
Also in:
intel-wired-lan, kernel-janitors, lkml
Subsystem:
intel ethernet drivers, networking drivers, the rest · Maintainers:
Tony Nguyen, Przemek Kitszel, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Colin Ian King <redacted>
Currently if the stat type is invalid then data[i] is being set
either by dereferencing a null pointer p, or it is reading from
an incorrect previous location if we had a valid stat type
previously. Fix this by nullify pointer p if a stat type is
invalid and only setting data if p is not null.
Detected by CoverityScan, CID#113385 ("Explicit null dereferenced")
Signed-off-by: Colin Ian King <redacted>
---
drivers/net/ethernet/intel/e1000/e1000_ethtool.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
index ec8aa4562cc9..724c93a6ea92 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c@@ -1824,7 +1824,7 @@ static void e1000_get_ethtool_stats(struct net_device *netdev, { struct e1000_adapter *adapter = netdev_priv(netdev); int i; - char *p = NULL; + char *p; const struct e1000_stats *stat = e1000_gstrings_stats; e1000_update_stats(adapter);
@@ -1837,16 +1837,18 @@ static void e1000_get_ethtool_stats(struct net_device *netdev, p = (char *)adapter + stat->stat_offset; break; default: + p = NULL; WARN_ONCE(1, "Invalid E1000 stat type: %u index %d\n", stat->type, i); break; } - if (stat->sizeof_stat == sizeof(u64)) - data[i] = *(u64 *)p; - else - data[i] = *(u32 *)p; - + if (p) { + if (stat->sizeof_stat == sizeof(u64)) + data[i] = *(u64 *)p; + else + data[i] = *(u32 *)p; + } stat++; } /* BUG_ON(i != E1000_STATS_LEN); */
--
2.14.1