From: Roman Bolshakov Date: Tue, 2 Jul 2019 19:16:38 +0000 (+0300) Subject: scsi: target/iblock: Fix overrun in WRITE SAME emulation X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=5676234f20fef02f6ca9bd66c63a8860fce62645;p=linux.git scsi: target/iblock: Fix overrun in WRITE SAME emulation WRITE SAME corrupts data on the block device behind iblock if the command is emulated. The emulation code issues (M - 1) * N times more bios than requested, where M is the number of 512 blocks per real block size and N is the NUMBER OF LOGICAL BLOCKS specified in WRITE SAME command. So, for a device with 4k blocks, 7 * N more LBAs gets written after the requested range. The issue happens because the number of 512 byte sectors to be written is decreased one by one while the real bios are typically from 1 to 8 512 byte sectors per bio. Fixes: c66ac9db8d4a ("[SCSI] target: Add LIO target core v4.0.0-rc6") Cc: Signed-off-by: Roman Bolshakov Reviewed-by: Bart Van Assche Signed-off-by: Martin K. Petersen --- diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c index b5ed9c3770605..efebacd361012 100644 --- a/drivers/target/target_core_iblock.c +++ b/drivers/target/target_core_iblock.c @@ -515,7 +515,7 @@ iblock_execute_write_same(struct se_cmd *cmd) /* Always in 512 byte units for Linux/Block */ block_lba += sg->length >> SECTOR_SHIFT; - sectors -= 1; + sectors -= sg->length >> SECTOR_SHIFT; } iblock_submit_bios(&list);