ahc_lookup_scb() may return a null pointer and further lead to null-pointer-dereference in case DATA_OVERRUN. Fix this by adding a null check. Signed-off-by: Dinghao Liu <dinghao.liu@xxxxxxxxxx> --- drivers/scsi/aic7xxx/aic7xxx_core.c | 72 +++++++++++++++-------------- 1 file changed, 37 insertions(+), 35 deletions(-) diff --git a/drivers/scsi/aic7xxx/aic7xxx_core.c b/drivers/scsi/aic7xxx/aic7xxx_core.c index 4b04ab8908f8..3a1cd6a0334e 100644 --- a/drivers/scsi/aic7xxx/aic7xxx_core.c +++ b/drivers/scsi/aic7xxx/aic7xxx_core.c @@ -1382,43 +1382,45 @@ ahc_handle_seqint(struct ahc_softc *ahc, u_int intstat) u_int i; scb = ahc_lookup_scb(ahc, scbindex); - for (i = 0; i < num_phases; i++) { - if (lastphase == ahc_phase_table[i].phase) - break; - } - ahc_print_path(ahc, scb); - printk("data overrun detected %s." - " Tag == 0x%x.\n", - ahc_phase_table[i].phasemsg, - scb->hscb->tag); - ahc_print_path(ahc, scb); - printk("%s seen Data Phase. Length = %ld. NumSGs = %d.\n", - ahc_inb(ahc, SEQ_FLAGS) & DPHASE ? "Have" : "Haven't", - ahc_get_transfer_length(scb), scb->sg_count); - if (scb->sg_count > 0) { - for (i = 0; i < scb->sg_count; i++) { - - printk("sg[%d] - Addr 0x%x%x : Length %d\n", - i, - (ahc_le32toh(scb->sg_list[i].len) >> 24 - & SG_HIGH_ADDR_BITS), - ahc_le32toh(scb->sg_list[i].addr), - ahc_le32toh(scb->sg_list[i].len) - & AHC_SG_LEN_MASK); + if (scb != NULL) { + for (i = 0; i < num_phases; i++) { + if (lastphase == ahc_phase_table[i].phase) + break; } + ahc_print_path(ahc, scb); + printk("data overrun detected %s." + " Tag == 0x%x.\n", + ahc_phase_table[i].phasemsg, + scb->hscb->tag); + ahc_print_path(ahc, scb); + printk("%s seen Data Phase. Length = %ld. NumSGs = %d.\n", + ahc_inb(ahc, SEQ_FLAGS) & DPHASE ? "Have" : "Haven't", + ahc_get_transfer_length(scb), scb->sg_count); + if (scb->sg_count > 0) { + for (i = 0; i < scb->sg_count; i++) { + + printk("sg[%d] - Addr 0x%x%x : Length %d\n", + i, + (ahc_le32toh(scb->sg_list[i].len) >> 24 + & SG_HIGH_ADDR_BITS), + ahc_le32toh(scb->sg_list[i].addr), + ahc_le32toh(scb->sg_list[i].len) + & AHC_SG_LEN_MASK); + } + } + /* + * Set this and it will take effect when the + * target does a command complete. + */ + ahc_freeze_devq(ahc, scb); + if ((scb->flags & SCB_SENSE) == 0) { + ahc_set_transaction_status(scb, CAM_DATA_RUN_ERR); + } else { + scb->flags &= ~SCB_SENSE; + ahc_set_transaction_status(scb, CAM_AUTOSENSE_FAIL); + } + ahc_freeze_scb(scb); } - /* - * Set this and it will take effect when the - * target does a command complete. - */ - ahc_freeze_devq(ahc, scb); - if ((scb->flags & SCB_SENSE) == 0) { - ahc_set_transaction_status(scb, CAM_DATA_RUN_ERR); - } else { - scb->flags &= ~SCB_SENSE; - ahc_set_transaction_status(scb, CAM_AUTOSENSE_FAIL); - } - ahc_freeze_scb(scb); if ((ahc->features & AHC_ULTRA2) != 0) { /* -- 2.17.1