If the module parameter virtual_gb is greater than 0, the READ command may request the blocks which exceed actual ramdisk storage (fake_storep). prot_verify_read() should treat those blocks as wrap around the end of fake_storep. But it actually causes fake_storep and dif_storep buffer overruns.
This fixes these buffer overruns. In order to simplify the fix, this also introduces fake_store() and dif_store() which return corresponding wrap around addresses. Signed-off-by: Akinobu Mita <[email protected]> Cc: "James E.J. Bottomley" <[email protected]> Cc: Douglas Gilbert <[email protected]> Cc: "Martin K. Petersen" <[email protected]> Cc: [email protected] --- drivers/scsi/scsi_debug.c | 48 +++++++++++++++++++++++++++++------------------ 1 file changed, 30 insertions(+), 18 deletions(-) diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index 01c0ffa..f640b6b 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -293,6 +293,20 @@ static unsigned char ctrl_m_pg[] = {0xa, 10, 2, 0, 0, 0, 0, 0, static unsigned char iec_m_pg[] = {0x1c, 0xa, 0x08, 0, 0, 0, 0, 0, 0, 0, 0x0, 0x0}; +static void *fake_store(unsigned long long lba) +{ + lba = do_div(lba, sdebug_store_sectors); + + return fake_storep + lba * scsi_debug_sector_size; +} + +static struct sd_dif_tuple *dif_store(sector_t sector) +{ + sector = do_div(sector, sdebug_store_sectors); + + return dif_storep + sector; +} + static int sdebug_add_adapter(void); static void sdebug_remove_adapter(void); @@ -1782,24 +1796,19 @@ static int prot_verify_read(struct scsi_cmnd *SCpnt, sector_t start_sec, struct scatterlist *psgl; struct sd_dif_tuple *sdt; sector_t sector; - sector_t tmp_sec = start_sec; void *paddr; + const void *dif_store_end = dif_storep + sdebug_store_sectors; - start_sec = do_div(tmp_sec, sdebug_store_sectors); - - sdt = dif_storep + start_sec; - - for (i = 0 ; i < sectors ; i++) { + for (i = 0; i < sectors; i++) { int ret; - if (sdt[i].app_tag == 0xffff) - continue; - sector = start_sec + i; + sdt = dif_store(sector); - ret = dif_verify(&sdt[i], - fake_storep + sector * scsi_debug_sector_size, - sector, ei_lba); + if (sdt->app_tag == 0xffff) + continue; + + ret = dif_verify(sdt, fake_store(sector), sector, ei_lba); if (ret) { dif_errors++; return ret; @@ -1814,16 +1823,19 @@ static int prot_verify_read(struct scsi_cmnd *SCpnt, sector_t start_sec, scsi_for_each_prot_sg(SCpnt, psgl, scsi_prot_sg_count(SCpnt), i) { int len = min(psgl->length, resid); + void *start = dif_store(sector); + int rest = 0; + + if (dif_store_end < start + len) + rest = start + len - dif_store_end; paddr = kmap_atomic(sg_page(psgl)) + psgl->offset; - memcpy(paddr, dif_storep + sector, len); + memcpy(paddr, start, len - rest); + + if (rest) + memcpy(paddr + len - rest, dif_storep, rest); sector += len / sizeof(*dif_storep); - if (sector >= sdebug_store_sectors) { - /* Force wrap */ - tmp_sec = sector; - sector = do_div(tmp_sec, sdebug_store_sectors); - } resid -= len; kunmap_atomic(paddr); } -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
