kernel/git/stable/linux.git/net/smc, branch linux-5.8.y

net/smc: fix valid DMBE buffer sizes

2020-10-29T09:07:01+00:00

[ Upstream commit ef12ad45880b696eb993d86c481ca891836ab593 ] The SMCD_DMBE_SIZES should include all valid DMBE buffer sizes, so the correct value is 6 which means 1MB. With 7 the registration of an ISM buffer would always fail because of the invalid size requested. Fix that and set the value to 6. Fixes: c6ba7c9ba43d ("net/smc: add base infrastructure for SMC-D and ISM") Signed-off-by: Karsten Graul Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net/smc: fix use-after-free of delayed events

2020-10-29T09:07:00+00:00

[ Upstream commit d535ca1367787ddc8bff22d679a11f864c8228bc ] When a delayed event is enqueued then the event worker will send this event the next time it is running and no other flow is currently active. The event handler is called for the delayed event, and the pointer to the event keeps set in lgr->delayed_event. This pointer is cleared later in the processing by smc_llc_flow_start(). This can lead to a use-after-free condition when the processing does not reach smc_llc_flow_start(), but frees the event because of an error situation. Then the delayed_event pointer is still set but the event is freed. Fix this by always clearing the delayed event pointer when the event is provided to the event handler for processing, and remove the code to clear it in smc_llc_flow_start(). Fixes: 555da9af827d ("net/smc: add event-based llc_flow framework") Signed-off-by: Karsten Graul Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net/smc: Prevent kernel-infoleak in __smc_diag_dump()

2020-08-27T07:31:47+00:00

[ Upstream commit ce51f63e63c52a4e1eee4dd040fb0ba0af3b43ab ] __smc_diag_dump() is potentially copying uninitialized kernel stack memory into socket buffers, since the compiler may leave a 4-byte hole near the beginning of `struct smcd_diag_dmbinfo`. Fix it by initializing `dinfo` with memset(). Fixes: 4b1b7d3b30a6 ("net/smc: add SMC-D diag support") Suggested-by: Dan Carpenter Signed-off-by: Peilin Ye Signed-off-by: Ursula Braun Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net/smc: fix dmb buffer shortage

2020-07-21T00:52:25+00:00

There is a current limit of 1920 registered dmb buffers per ISM device for smc-d. One link group can contain 255 connections, each connection is using one dmb buffer. When the connection is closed then the registered buffer is held in a queue and is reused by the next connection. When a link group is 'full' then another link group is created and uses an own buffer pool. The link groups are added to a list using list_add() which puts a new link group to the first position in the list. In the situation that many connections are opened (>1920) and a few of them stay open while others are closed quickly we end up with at least 8 link groups. For a new connection a matching link group is looked up, iterating over the list of link groups. The trailing 7 link groups all have registered dmb buffers which could be reused, while the first link group has only a few dmb buffers and then hit the 1920 limit. Because the first link group is not full (255 connection limit not reached) it is chosen and finally the connection falls back to TCP because there is no dmb buffer available in this link group. There are multiple ways to fix that: using list_add_tail() allows to scan older link groups first for free buffers which ensures that buffers are reused first. This fixes the problem for smc-r link groups as well. For smc-d there is an even better way to address this problem because smc-d does not have the 255 connections per link group limit. So fix the problem for smc-d by allowing large link groups. Fixes: c6ba7c9ba43d ("net/smc: add base infrastructure for SMC-D and ISM") Reviewed-by: Ursula Braun Signed-off-by: Karsten Graul Signed-off-by: David S. Miller

net/smc: put slot when connection is killed

2020-07-21T00:52:25+00:00

To get a send slot smc_wr_tx_get_free_slot() is called, which might wait for a free slot. When smc_wr_tx_get_free_slot() returns there is a check if the connection was killed in the meantime. In that case don't only return an error, but also put back the free slot. Fixes: b290098092e4 ("net/smc: cancel send and receive for terminated socket") Reviewed-by: Ursula Braun Signed-off-by: Karsten Graul Signed-off-by: David S. Miller

net/smc: fix restoring of fallback changes

2020-07-19T22:30:23+00:00

When a listen socket is closed then all non-accepted sockets in its accept queue are to be released. Inside __smc_release() the helper smc_restore_fallback_changes() restores the changes done to the socket without to check if the clcsocket has a file set. This can result in a crash. Fix this by checking the file pointer first. Reviewed-by: Ursula Braun Fixes: f536dffc0b79 ("net/smc: fix closing of fallback SMC sockets") Signed-off-by: Karsten Graul Signed-off-by: David S. Miller

net/smc: remove freed buffer from list

2020-07-19T22:30:23+00:00

Two buffers are allocated for each SMC connection. Each buffer is added to a buffer list after creation. When the second buffer allocation fails, the first buffer is freed but not deleted from the list. This might result in crashes when another connection picks up the freed buffer later and starts to work with it. Reviewed-by: Ursula Braun Fixes: 6511aad3f039 ("net/smc: change smc_buf_free function parameters") Signed-off-by: Karsten Graul Signed-off-by: David S. Miller

net/smc: do not call dma sync for unmapped memory

2020-07-19T22:30:22+00:00

The dma related ...sync_sg... functions check the link state before the dma function is actually called. But the check in smc_link_usable() allows links in ACTIVATING state which are not yet mapped to dma memory. Under high load it may happen that the sync_sg functions are called for such a link which results in an debug output like DMA-API: mlx5_core 0002:00:00.0: device driver tries to sync DMA memory it has not allocated [device address=0x0000000103370000] [size=65536 bytes] To fix that introduce a helper to check for the link state ACTIVE and use it where appropriate. And move the link state update to ACTIVATING to the end of smcr_link_init() when most initial setup is done. Reviewed-by: Ursula Braun Fixes: d854fcbfaeda ("net/smc: add new link state and related helpers") Signed-off-by: Karsten Graul Signed-off-by: David S. Miller

net/smc: fix handling of delete link requests

2020-07-19T22:30:22+00:00

As smc client the delete link requests are assigned to the flow when _any_ flow is active. This may break other flows that do not expect delete link requests during their handling. Fix that by assigning the request only when an add link flow is active. With that fix the code for smc client and smc server is the same, so remove the separate handling. Reviewed-by: Ursula Braun Fixes: 9ec6bf19ec8b ("net/smc: llc_del_link_work and use the LLC flow for delete link") Signed-off-by: Karsten Graul Signed-off-by: David S. Miller

net/smc: move add link processing for new device into llc layer

2020-07-19T22:30:22+00:00

When a new ib device is up smc will send an add link invitation to the peer if needed. This is currently done with rudimentary flow control. Under high workload these add link invitations can disturb other llc flows because they arrive unexpected. Fix this by integrating the invitations into the normal llc event flow and handle them as a flow. While at it, check for already assigned requests in the flow before the new add link request is assigned. Reviewed-by: Ursula Braun Fixes: 1f90a05d9ff9 ("net/smc: add smcr_port_add() and smcr_link_up() processing") Signed-off-by: Karsten Graul Signed-off-by: David S. Miller