[PATCH] scsi: scsi_debug: fix return checks for kcalloc
From: George Kennedy
Date: Wed Nov 03 2021 - 15:04:21 EST
Change return checks from kcalloc() to now check for NULL and
ZERO_SIZE_PTR using the ZERO_OR_NULL_PTR macro or the following
crash can occur if ZERO_SIZE_PTR indicator is returned.
BUG: KASAN: null-ptr-deref in memcpy include/linux/fortify-string.h:191 [inline]
BUG: KASAN: null-ptr-deref in sg_copy_buffer+0x138/0x240 lib/scatterlist.c:974
Write of size 4 at addr 0000000000000010 by task syz-executor.1/22789
CPU: 1 PID: 22789 Comm: syz-executor.1 Not tainted 5.15.0-syzk #1
Hardware name: Red Hat KVM, BIOS 1.13.0-2
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:106
__kasan_report mm/kasan/report.c:446 [inline]
kasan_report.cold.14+0x112/0x117 mm/kasan/report.c:459
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x1a3/0x210 mm/kasan/generic.c:189
memcpy+0x3b/0x60 mm/kasan/shadow.c:66
memcpy include/linux/fortify-string.h:191 [inline]
sg_copy_buffer+0x138/0x240 lib/scatterlist.c:974
do_dout_fetch drivers/scsi/scsi_debug.c:2954 [inline]
do_dout_fetch drivers/scsi/scsi_debug.c:2946 [inline]
resp_verify+0x49e/0x930 drivers/scsi/scsi_debug.c:4276
schedule_resp+0x4d8/0x1a70 drivers/scsi/scsi_debug.c:5478
scsi_debug_queuecommand+0x8c9/0x1ec0 drivers/scsi/scsi_debug.c:7533
scsi_dispatch_cmd drivers/scsi/scsi_lib.c:1520 [inline]
scsi_queue_rq+0x16b0/0x2d40 drivers/scsi/scsi_lib.c:1699
blk_mq_dispatch_rq_list+0xb9b/0x2700 block/blk-mq.c:1639
__blk_mq_sched_dispatch_requests+0x28f/0x590 block/blk-mq-sched.c:325
blk_mq_sched_dispatch_requests+0x105/0x190 block/blk-mq-sched.c:358
__blk_mq_run_hw_queue+0xe5/0x150 block/blk-mq.c:1761
__blk_mq_delay_run_hw_queue+0x4f8/0x5c0 block/blk-mq.c:1838
blk_mq_run_hw_queue+0x18d/0x350 block/blk-mq.c:1891
blk_mq_sched_insert_request+0x3db/0x4e0 block/blk-mq-sched.c:474
blk_execute_rq_nowait+0x16b/0x1c0 block/blk-exec.c:62
blk_execute_rq+0xdb/0x360 block/blk-exec.c:102
sg_scsi_ioctl drivers/scsi/scsi_ioctl.c:621 [inline]
scsi_ioctl+0x8bb/0x15c0 drivers/scsi/scsi_ioctl.c:930
sg_ioctl_common+0x172d/0x2710 drivers/scsi/sg.c:1112
sg_ioctl+0xa2/0x180 drivers/scsi/sg.c:1165
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x19d/0x220 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Reported-by: syzkaller <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: George Kennedy <george.kennedy@xxxxxxxxxx>
---
drivers/scsi/scsi_debug.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 40b473e..222e985 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -3909,7 +3909,7 @@ static int resp_comp_write(struct scsi_cmnd *scp,
return ret;
dnum = 2 * num;
arr = kcalloc(lb_size, dnum, GFP_ATOMIC);
- if (NULL == arr) {
+ if (ZERO_OR_NULL_PTR(arr)) {
mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
INSUFF_RES_ASCQ);
return check_condition_result;
@@ -4265,7 +4265,7 @@ static int resp_verify(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
return ret;
arr = kcalloc(lb_size, vnum, GFP_ATOMIC);
- if (!arr) {
+ if (ZERO_OR_NULL_PTR(arr)) {
mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
INSUFF_RES_ASCQ);
return check_condition_result;
@@ -4334,7 +4334,7 @@ static int resp_report_zones(struct scsi_cmnd *scp,
max_zones);
arr = kcalloc(RZONES_DESC_HD, alloc_len, GFP_ATOMIC);
- if (!arr) {
+ if (ZERO_OR_NULL_PTR(arr)) {
mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
INSUFF_RES_ASCQ);
return check_condition_result;
--
1.8.3.1