[PATCH net] sfc: fix potential stack corruption from running past stat bitmask
From: Edward Cree <hidden>
Date: 2016-08-26 10:19:47
Subsystem:
networking drivers, sfc network driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Edward Cree, Linus Torvalds
From: Andrew Rybchenko <redacted>
On 32-bit systems, mask is only an array of 3 longs, not 4, so don't try
to write to mask[3].
Also include build-time checks in case the size of the bitmask changes.
Fixes: 3c36a2aded8c ("sfc: display vadaptor statistics for all interfaces")
Signed-off-by: Edward Cree <redacted>
---
drivers/net/ethernet/sfc/ef10.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index 1f30912..6e0a4f2 100644
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c@@ -1304,13 +1304,14 @@ static void efx_ef10_get_stat_mask(struct efx_nic *efx, unsigned long *mask) } #if BITS_PER_LONG == 64 + BUILD_BUG_ON(BITS_TO_LONGS(EF10_STAT_COUNT) != 2); mask[0] = raw_mask[0]; mask[1] = raw_mask[1]; #else + BUILD_BUG_ON(BITS_TO_LONGS(EF10_STAT_COUNT) != 3); mask[0] = raw_mask[0] & 0xffffffff; mask[1] = raw_mask[0] >> 32; mask[2] = raw_mask[1] & 0xffffffff; - mask[3] = raw_mask[1] >> 32; #endif }