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Zixuan Fu authored
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: d1a890fa ("net: VMware virtual Ethernet NIC driver: vmxnet3") Reported-by: TOTE Robot <oslab@tsinghua.edu.cn> Signed-off-by: Zixuan Fu <r33s3n6@gmail.com> Link: https://lore.kernel.org/r/20220514050711.2636709-1-r33s3n6@gmail.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>
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