From: Helge Deller deller@gmx.de
commit 2f4843b172c2c0360ee7792ad98025fae7baefde upstream.
The mptscsih_remove() function triggers a kernel oops if the Scsi_Host pointer (ioc->sh) is NULL, as can be seen in this syslog:
ioc0: LSI53C1030 B2: Capabilities={Initiator,Target} Begin: Waiting for root file system ... scsi host2: error handler thread failed to spawn, error = -4 mptspi: ioc0: WARNING - Unable to register controller with SCSI subsystem Backtrace: [<000000001045b7cc>] mptspi_probe+0x248/0x3d0 [mptspi] [<0000000040946470>] pci_device_probe+0x1ac/0x2d8 [<0000000040add668>] really_probe+0x1bc/0x988 [<0000000040ade704>] driver_probe_device+0x160/0x218 [<0000000040adee24>] device_driver_attach+0x160/0x188 [<0000000040adef90>] __driver_attach+0x144/0x320 [<0000000040ad7c78>] bus_for_each_dev+0xd4/0x158 [<0000000040adc138>] driver_attach+0x4c/0x80 [<0000000040adb3ec>] bus_add_driver+0x3e0/0x498 [<0000000040ae0130>] driver_register+0xf4/0x298 [<00000000409450c4>] __pci_register_driver+0x78/0xa8 [<000000000007d248>] mptspi_init+0x18c/0x1c4 [mptspi]
This patch adds the necessary NULL-pointer checks. Successfully tested on a HP C8000 parisc workstation with buggy SCSI drives.
Link: https://lore.kernel.org/r/20201022090005.GA9000@ls3530.fritz.box Cc: stable@vger.kernel.org Signed-off-by: Helge Deller deller@gmx.de Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/message/fusion/mptscsih.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
--- a/drivers/message/fusion/mptscsih.c +++ b/drivers/message/fusion/mptscsih.c @@ -1176,8 +1176,10 @@ mptscsih_remove(struct pci_dev *pdev) MPT_SCSI_HOST *hd; int sz1;
- if((hd = shost_priv(host)) == NULL) - return; + if (host == NULL) + hd = NULL; + else + hd = shost_priv(host);
mptscsih_shutdown(pdev);
@@ -1193,14 +1195,15 @@ mptscsih_remove(struct pci_dev *pdev) "Free'd ScsiLookup (%d) memory\n", ioc->name, sz1));
- kfree(hd->info_kbuf); + if (hd) + kfree(hd->info_kbuf);
/* NULL the Scsi_Host pointer */ ioc->sh = NULL;
- scsi_host_put(host); - + if (host) + scsi_host_put(host); mpt_detach(pdev);
}