From edf410cb74dc612fd47ef5be319c5a0bcd6e6ccd Mon Sep 17 00:00:00 2001 From: Zixuan Fu Date: Sat, 14 May 2022 13:07:11 +0800 Subject: [PATCH] net: vmxnet3: fix possible NULL pointer dereference in vmxnet3_rq_cleanup() In vmxnet3_rq_create(), when dma_alloc_coherent() fails, vmxnet3_rq_destroy() is called. It sets rq->rx_ring[i].base to NULL. Then vmxnet3_rq_create() returns an error to its callers mxnet3_rq_create_all() -> vmxnet3_change_mtu(). Then vmxnet3_change_mtu() calls vmxnet3_force_close() -> dev_close() in error handling code. And the driver calls vmxnet3_close() -> vmxnet3_quiesce_dev() -> vmxnet3_rq_cleanup_all() -> vmxnet3_rq_cleanup(). In vmxnet3_rq_cleanup(), rq->rx_ring[ring_idx].base is accessed, but this variable is NULL, causing a NULL pointer dereference. To fix this possible bug, an if statement is added to check whether rq->rx_ring[0].base is NULL in vmxnet3_rq_cleanup() and exit early if so. The error log in our fault-injection testing is shown as follows: [ 65.220135] BUG: kernel NULL pointer dereference, address: 0000000000000008 ... [ 65.222633] RIP: 0010:vmxnet3_rq_cleanup_all+0x396/0x4e0 [vmxnet3] ... [ 65.227977] Call Trace: ... [ 65.228262] vmxnet3_quiesce_dev+0x80f/0x8a0 [vmxnet3] [ 65.228580] vmxnet3_close+0x2c4/0x3f0 [vmxnet3] [ 65.228866] __dev_close_many+0x288/0x350 [ 65.229607] dev_close_many+0xa4/0x480 [ 65.231124] dev_close+0x138/0x230 [ 65.231933] vmxnet3_force_close+0x1f0/0x240 [vmxnet3] [ 65.232248] vmxnet3_change_mtu+0x75d/0x920 [vmxnet3] ... Fixes: d1a890fa37f27 ("net: VMware virtual Ethernet NIC driver: vmxnet3") Reported-by: TOTE Robot Signed-off-by: Zixuan Fu Link: https://lore.kernel.org/r/20220514050711.2636709-1-r33s3n6@gmail.com Signed-off-by: Paolo Abeni --- drivers/net/vmxnet3/vmxnet3_drv.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c index 1154f188421280..93e8d119d45f6b 100644 --- a/drivers/net/vmxnet3/vmxnet3_drv.c +++ b/drivers/net/vmxnet3/vmxnet3_drv.c @@ -1668,6 +1668,10 @@ vmxnet3_rq_cleanup(struct vmxnet3_rx_queue *rq, u32 i, ring_idx; struct Vmxnet3_RxDesc *rxd; + /* ring has already been cleaned up */ + if (!rq->rx_ring[0].base) + return; + for (ring_idx = 0; ring_idx < 2; ring_idx++) { for (i = 0; i < rq->rx_ring[ring_idx].size; i++) { #ifdef __BIG_ENDIAN_BITFIELD