Change min_t() to use type "unsigned int" instead of type "int" to avoid stack out of bounds. With min_t() type "int" the values get sign extended and the larger value gets used causing stack out of bounds. BUG: KASAN: stack-out-of-bounds in memcpy include/linux/fortify-string.h:191 [inline] BUG: KASAN: stack-out-of-bounds in sg_copy_buffer+0x1de/0x240 lib/scatterlist.c:976 Read of size 127 at addr ffff888072607128 by task syz-executor.7/18707 CPU: 1 PID: 18707 Comm: syz-executor.7 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 print_address_description.constprop.9+0x28/0x160 mm/kasan/report.c:256 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold.14+0x7d/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+0x23/0x60 mm/kasan/shadow.c:65 memcpy include/linux/fortify-string.h:191 [inline] sg_copy_buffer+0x1de/0x240 lib/scatterlist.c:976 sg_copy_from_buffer+0x33/0x40 lib/scatterlist.c:1000 fill_from_dev_buffer.part.34+0x82/0x130 drivers/scsi/scsi_debug.c:1162 fill_from_dev_buffer drivers/scsi/scsi_debug.c:1888 [inline] resp_readcap16+0x365/0x3b0 drivers/scsi/scsi_debug.c:1887 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 sg_common_write.isra.18+0xeb3/0x2000 drivers/scsi/sg.c:836 sg_new_write.isra.19+0x570/0x8c0 drivers/scsi/sg.c:774 sg_ioctl_common+0x14d6/0x2710 drivers/scsi/sg.c:939 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 | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index 40b473e..e4c48fb 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -1189,7 +1189,7 @@ static int p_fill_from_dev_buffer(struct scsi_cmnd *scp, const void *arr, __func__, off_dst, scsi_bufflen(scp), act_len, scsi_get_resid(scp)); n = scsi_bufflen(scp) - (off_dst + act_len); - scsi_set_resid(scp, min_t(int, scsi_get_resid(scp), n)); + scsi_set_resid(scp, min_t(unsigned int, scsi_get_resid(scp), n)); return 0; } @@ -1714,7 +1714,7 @@ static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) } put_unaligned_be16(0x2100, arr + n); /* SPL-4 no version claimed */ ret = fill_from_dev_buffer(scp, arr, - min_t(int, alloc_len, SDEBUG_LONG_INQ_SZ)); + min_t(unsigned int, alloc_len, SDEBUG_LONG_INQ_SZ)); kfree(arr); return ret; } @@ -1774,7 +1774,7 @@ static int resp_requests(struct scsi_cmnd *scp, arr[7] = 0xa; } } - return fill_from_dev_buffer(scp, arr, min_t(int, len, alloc_len)); + return fill_from_dev_buffer(scp, arr, min_t(unsigned int, len, alloc_len)); } static int resp_start_stop(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) @@ -1885,7 +1885,7 @@ static int resp_readcap16(struct scsi_cmnd *scp, } return fill_from_dev_buffer(scp, arr, - min_t(int, alloc_len, SDEBUG_READCAP16_ARR_SZ)); + min_t(unsigned int, alloc_len, SDEBUG_READCAP16_ARR_SZ)); } #define SDEBUG_MAX_TGTPGS_ARR_SZ 1412 @@ -1959,9 +1959,9 @@ 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_t(unsigned int, alen, n); ret = fill_from_dev_buffer(scp, arr, - min_t(int, rlen, SDEBUG_MAX_TGTPGS_ARR_SZ)); + min_t(unsigned int, rlen, SDEBUG_MAX_TGTPGS_ARR_SZ)); kfree(arr); return ret; } @@ -2467,7 +2467,7 @@ static int resp_mode_sense(struct scsi_cmnd *scp, arr[0] = offset - 1; else put_unaligned_be16((offset - 2), arr + 0); - return fill_from_dev_buffer(scp, arr, min_t(int, alloc_len, offset)); + return fill_from_dev_buffer(scp, arr, min_t(unsigned int, alloc_len, offset)); } #define SDEBUG_MAX_MSELECT_SZ 512 @@ -2652,9 +2652,9 @@ static int resp_log_sense(struct scsi_cmnd *scp, mk_sense_invalid_fld(scp, SDEB_IN_CDB, 3, -1); return check_condition_result; } - len = min_t(int, get_unaligned_be16(arr + 2) + 4, alloc_len); + len = min_t(unsigned int, get_unaligned_be16(arr + 2) + 4, alloc_len); return fill_from_dev_buffer(scp, arr, - min_t(int, len, SDEBUG_MAX_INQ_ARR_SZ)); + min_t(unsigned int, len, SDEBUG_MAX_INQ_ARR_SZ)); } static inline bool sdebug_dev_is_zoned(struct sdebug_dev_info *devip) @@ -4425,7 +4425,7 @@ static int resp_report_zones(struct scsi_cmnd *scp, put_unaligned_be64(sdebug_capacity - 1, arr + 8); rep_len = (unsigned long)desc - (unsigned long)arr; - ret = fill_from_dev_buffer(scp, arr, min_t(int, alloc_len, rep_len)); + ret = fill_from_dev_buffer(scp, arr, min_t(unsigned int, alloc_len, rep_len)); fini: read_unlock(macc_lckp); -- 1.8.3.1
