| From | Andi Kleen <> | Subject | [PATCH] [251/275] ses: Avoid kernel panic when lun 0 is not mapped | Date | Wed, 30 Mar 2011 14:08:17 -0700 (PDT) |
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2.6.35-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Krishnasamy, Somasundaram <Somasundaram.Krishnasamy@lsi.com>
commit d1e12de804f9d8ad114786ca7c2ce593cba79891 upstream.
During device discovery, scsi mid layer sends INQUIRY command to LUN 0. If the LUN 0 is not mapped to host, it creates a temporary scsi_device with LUN id 0 and sends REPORT_LUNS command to it. After the REPORT_LUNS succeeds, it walks through the LUN table and adds each LUN found to sysfs. At the end of REPORT_LUNS lun table scan, it will delete the temporary scsi_device of LUN 0.
When scsi devices are added to sysfs, it calls add_dev function of all the registered class interfaces. If ses driver has been registered, ses_intf_add() of ses module will be called. This function calls scsi_device_enclosure() to check the inquiry data for EncServ bit. Since inquiry was not allocated for temporary LUN 0 scsi_device, it will cause NULL pointer exception.
To fix the problem, sdev->inquiry is checked for NULL before reading it.
Signed-off-by: Somasundaram Krishnasamy <Somasundaram.Krishnasamy@lsi.com> Signed-off-by: Babu Moger <babu.moger@lsi.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
--- include/scsi/scsi_device.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Index: linux-2.6.35.y/include/scsi/scsi_device.h =================================================================== --- linux-2.6.35.y.orig/include/scsi/scsi_device.h 2011-03-29 22:50:10.926978825 -0700 +++ linux-2.6.35.y/include/scsi/scsi_device.h 2011-03-29 23:03:03.501210582 -0700 @@ -451,7 +451,7 @@ } static inline int scsi_device_enclosure(struct scsi_device *sdev) { - return sdev->inquiry[6] & (1<<6); + return sdev->inquiry ? (sdev->inquiry[6] & (1<<6)) : 1; } static inline int scsi_device_protection(struct scsi_device *sdev)
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