3.2.96-rc1 review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter dan.carpenter@oracle.com
commit e6f77540c067b48dee10f1e33678415bfcc89017 upstream.
The value of "size" comes from the user. When we add "start + size" it could lead to an integer overflow bug.
It means we vmalloc() a lot more memory than we had intended. I believe that on 64 bit systems vmalloc() can succeed even if we ask it to allocate huge 4GB buffers. So we would get memory corruption and likely a crash when we call ha->isp_ops->write_optrom() and ->read_optrom().
Only root can trigger this bug.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=194061
Fixes: b7cc176c9eb3 ("[SCSI] qla2xxx: Allow region-based flash-part accesses.") Reported-by: shqking shqking@gmail.com Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/scsi/qla2xxx/qla_attr.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/scsi/qla2xxx/qla_attr.c +++ b/drivers/scsi/qla2xxx/qla_attr.c @@ -284,6 +284,8 @@ qla2x00_sysfs_write_optrom_ctl(struct fi return -EINVAL; if (start > ha->optrom_size) return -EINVAL; + if (size > ha->optrom_size - start) + size = ha->optrom_size - start;
mutex_lock(&ha->optrom_mutex); switch (val) { @@ -309,8 +311,7 @@ qla2x00_sysfs_write_optrom_ctl(struct fi }
ha->optrom_region_start = start; - ha->optrom_region_size = start + size > ha->optrom_size ? - ha->optrom_size - start : size; + ha->optrom_region_size = start + size;
ha->optrom_state = QLA_SREADING; ha->optrom_buffer = vmalloc(ha->optrom_region_size); @@ -381,8 +382,7 @@ qla2x00_sysfs_write_optrom_ctl(struct fi }
ha->optrom_region_start = start; - ha->optrom_region_size = start + size > ha->optrom_size ? - ha->optrom_size - start : size; + ha->optrom_region_size = start + size;
ha->optrom_state = QLA_SWRITING; ha->optrom_buffer = vmalloc(ha->optrom_region_size);