From ee0e6e69a772d601e152e5368a1da25d656122a8 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Thu, 5 Mar 2026 18:48:05 -0800 Subject: [PATCH] ata: libata-eh: Fix detection of deferred qc timeouts If the ata_qc_for_each_raw() loop finishes without finding a matching SCSI command for any QC, the variable qc will hold a pointer to the last element examined, which has the tag i == ATA_MAX_QUEUE - 1. This qc can match the port deferred QC (ap->deferred_qc). If that happens, the condition qc == ap->deferred_qc evaluates to true despite the loop not breaking with a match on the SCSI command for this QC. In that case, the error handler mistakenly intercepts a command that has not been issued yet and that has not timed out, and thus erroneously returning a timeout error. Fix the problem by checking for i < ATA_MAX_QUEUE in addition to qc == ap->deferred_qc. The problem was found by an experimental code review agent based on gemini-3.1-pro while reviewing backports into v6.18.y. Assisted-by: Gemini:gemini-3.1-pro Fixes: eddb98ad9364 ("ata: libata-eh: correctly handle deferred qc timeouts") Signed-off-by: Guenter Roeck [cassel: modified commit log as suggested by Damien] Reviewed-by: Damien Le Moal Signed-off-by: Niklas Cassel --- drivers/ata/libata-eh.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 563432400f72..23be85418b3b 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -647,7 +647,7 @@ void ata_scsi_cmd_error_handler(struct Scsi_Host *host, struct ata_port *ap, break; } - if (qc == ap->deferred_qc) { + if (i < ATA_MAX_QUEUE && qc == ap->deferred_qc) { /* * This is a deferred command that timed out while * waiting for the command queue to drain. Since the qc