This is a note to let you know that I've just added the patch titled scsi: fnic: Finish scsi_cmnd before dropping the spinlock to the 5.16-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: scsi-fnic-finish-scsi_cmnd-before-dropping-the-spinl.patch and it can be found in the queue-5.16 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 41ed00e2e0ef21f64a79469709fe29f55a64f56d Author: David Jeffery <djeffery@xxxxxxxxxx> Date: Fri Mar 11 13:43:59 2022 -0500 scsi: fnic: Finish scsi_cmnd before dropping the spinlock [ Upstream commit 733ab7e1b5d1041204c4ca7373f6e6f9d08e3283 ] When aborting a SCSI command through fnic, there is a race with the fnic interrupt handler which can result in the SCSI command and its request being completed twice. If the interrupt handler claims the command by setting CMD_SP to NULL first, the abort handler assumes the interrupt handler has completed the command and returns SUCCESS, causing the request for the scsi_cmnd to be re-queued. But the interrupt handler may not have finished the command yet. After it drops the spinlock protecting CMD_SP, it does memory cleanup before finally calling scsi_done() to complete the scsi_cmnd. If the call to scsi_done occurs after the abort handler finishes and re-queues the request, the completion of the scsi_cmnd will advance and try to double complete a request already queued for retry. This patch fixes the issue by moving scsi_done() and any other use of scsi_cmnd to before the spinlock is released by the interrupt handler. Link: https://lore.kernel.org/r/20220311184359.2345319-1-djeffery@xxxxxxxxxx Reviewed-by: Laurence Oberman <loberman@xxxxxxxxxx> Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx> Signed-off-by: David Jeffery <djeffery@xxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/scsi/fnic/fnic_scsi.c b/drivers/scsi/fnic/fnic_scsi.c index 88c549f257db..40a52feb315d 100644 --- a/drivers/scsi/fnic/fnic_scsi.c +++ b/drivers/scsi/fnic/fnic_scsi.c @@ -986,8 +986,6 @@ static void fnic_fcpio_icmnd_cmpl_handler(struct fnic *fnic, CMD_SP(sc) = NULL; CMD_FLAGS(sc) |= FNIC_IO_DONE; - spin_unlock_irqrestore(io_lock, flags); - if (hdr_status != FCPIO_SUCCESS) { atomic64_inc(&fnic_stats->io_stats.io_failures); shost_printk(KERN_ERR, fnic->lport->host, "hdr status = %s\n", @@ -996,8 +994,6 @@ static void fnic_fcpio_icmnd_cmpl_handler(struct fnic *fnic, fnic_release_ioreq_buf(fnic, io_req, sc); - mempool_free(io_req, fnic->io_req_pool); - cmd_trace = ((u64)hdr_status << 56) | (u64)icmnd_cmpl->scsi_status << 48 | (u64)icmnd_cmpl->flags << 40 | (u64)sc->cmnd[0] << 32 | @@ -1021,6 +1017,12 @@ static void fnic_fcpio_icmnd_cmpl_handler(struct fnic *fnic, } else fnic->lport->host_stats.fcp_control_requests++; + /* Call SCSI completion function to complete the IO */ + scsi_done(sc); + spin_unlock_irqrestore(io_lock, flags); + + mempool_free(io_req, fnic->io_req_pool); + atomic64_dec(&fnic_stats->io_stats.active_ios); if (atomic64_read(&fnic->io_cmpl_skip)) atomic64_dec(&fnic->io_cmpl_skip); @@ -1049,9 +1051,6 @@ static void fnic_fcpio_icmnd_cmpl_handler(struct fnic *fnic, if(io_duration_time > atomic64_read(&fnic_stats->io_stats.current_max_io_time)) atomic64_set(&fnic_stats->io_stats.current_max_io_time, io_duration_time); } - - /* Call SCSI completion function to complete the IO */ - scsi_done(sc); } /* fnic_fcpio_itmf_cmpl_handler