From: Bart Van Assche <bvanassche@xxxxxxx> [ Upstream commit d3d9c4570285090b533b00946b72647361f0345b ] If param_offset > buff_len then the memcpy() statement in ufshcd_read_desc_param() corrupts memory since it copies 256 + buff_len - param_offset bytes into a buffer with size buff_len. Since param_offset < 256 this results in writing past the bound of the output buffer. Link: https://lore.kernel.org/r/20210722033439.26550-2-bvanassche@xxxxxxx Fixes: cbe193f6f093 ("scsi: ufs: Fix potential NULL pointer access during memcpy") Reviewed-by: Avri Altman <avri.altman@xxxxxxx> Reviewed-by: Daejun Park <daejun7.park@xxxxxxxxxxx> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/scsi/ufs/ufshcd.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 854c96e63007..4dabd09400c6 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -3249,9 +3249,11 @@ int ufshcd_read_desc_param(struct ufs_hba *hba, if (is_kmalloc) { /* Make sure we don't copy more data than available */ - if (param_offset + param_size > buff_len) - param_size = buff_len - param_offset; - memcpy(param_read_buf, &desc_buf[param_offset], param_size); + if (param_offset >= buff_len) + ret = -EINVAL; + else + memcpy(param_read_buf, &desc_buf[param_offset], + min_t(u32, param_size, buff_len - param_offset)); } out: if (is_kmalloc) -- 2.30.2
