[PATCH -next 2/2] scsi:scsi_debug: Fix potential OOB in resp_report_tgtpgs

Ye Bin
2021-08-18T02:04:06Z

As alloc_len's type is 'int', and value get from cmd which maybe negetive.
So it will pass huge len to fill_from_dev_buffer, lead to OOB.

Signed-off-by: Ye Bin <yebin10@huawei.com>
---
drivers/scsi/scsi_debug.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index be0440545744..ead65cdfb522 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -1896,8 +1896,9 @@ static int resp_report_tgtpgs(struct scsi_cmnd *scp,
unsigned char *cmd = scp->cmnd;
unsigned char *arr;
int host_no = devip->sdbg_host->shost->host_no;
- int n, ret, alen, rlen;
int port_group_a, port_group_b, port_a, port_b;
+ u32 alen, n, rlen;
+ int ret;

alen = get_unaligned_be32(cmd + 6);
arr = kzalloc(SDEBUG_MAX_TGTPGS_ARR_SZ, GFP_ATOMIC);
@@ -1959,9 +1960,9 @@ static int resp_report_tgtpgs(struct scsi_cmnd *scp,
* - The constructed command length
* - The maximum array size
*/
- rlen = min_t(int, alen, n);
+ rlen = min(alen, n);
ret = fill_from_dev_buffer(scp, arr,
- min_t(int, rlen, SDEBUG_MAX_TGTPGS_ARR_SZ));
+ min_t(u32, rlen, SDEBUG_MAX_TGTPGS_ARR_SZ));
kfree(arr);
return ret;
}
--
2.31.1