NTB: ntb_transport: Fail TX enqueue when the QP link is down

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Commit f195a1a6fe ("ntb: Drop packets when qp link is down") meant to
make ntb_transport_tx_enqueue() drop packets submitted while the QP link
is down, but it only returns 0 without consuming the packet. Zero means
success by this function's contract, so ntb_netdev reports NETDEV_TX_OK
and forgets the skb: nothing queued it, nothing frees it, and it leaks,
one skb for every transmit racing a link-down.

Return -ENOLINK instead, restoring the contract that a non-zero return
leaves the buffer owned by the caller. With the preceding patch,
ntb_netdev frees the skb on non-retryable enqueue failures and returns
NETDEV_TX_OK, so a packet racing with link-down is dropped without leaking
or entering a busy retry loop.

Fixes: f195a1a6fe ("ntb: Drop packets when qp link is down")
Cc: stable@vger.kernel.org
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/20260817053519.4135287-4-den@valinux.co.jp
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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This commit is contained in:

Koichiro Den 2026-08-17 14:35:18 +09:00 • committed by Jakub Kicinski

parent 8aaa47351d

commit 873ce713fe

1 changed files with 1 additions and 2 deletions

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drivers/ntb/ntb_transport.c

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