net: usb: lan78xx: limit size of local TSO packets
authorEric Dumazet <edumazet@google.com>
Mon, 13 Jan 2020 17:27:11 +0000 (09:27 -0800)
committerDavid S. Miller <davem@davemloft.net>
Tue, 14 Jan 2020 19:04:42 +0000 (11:04 -0800)
commitf8d7408a4d7f60f8b2df0f81decdc882dd9c20dc
tree4e0109b6d619de6896dd63a004a862443d56cf21
parent75718584cb3c64e6269109d4d54f888ac5a5fd15
net: usb: lan78xx: limit size of local TSO packets

lan78xx_tx_bh() makes sure to not exceed MAX_SINGLE_PACKET_SIZE
bytes in the aggregated packets it builds, but does
nothing to prevent large GSO packets being submitted.

Pierre-Francois reported various hangs when/if TSO is enabled.

For localy generated packets, we can use netif_set_gso_max_size()
to limit the size of TSO packets.

Note that forwarded packets could still hit the issue,
so a complete fix might require implementing .ndo_features_check
for this driver, forcing a software segmentation if the size
of the TSO packet exceeds MAX_SINGLE_PACKET_SIZE.

Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: RENARD Pierre-Francois <pfrenard@gmail.com>
Tested-by: RENARD Pierre-Francois <pfrenard@gmail.com>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Woojung Huh <woojung.huh@microchip.com>
Cc: Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/usb/lan78xx.c