[PATCH v3 01/18] scsi: ufs: Fix memory corruption by ufshcd_read_desc_param()
From: Bart Van Assche <bvanassche@acm.org>
Date: 2021-07-22 03:35:00
Subsystem:
scsi subsystem, the rest · Maintainers:
"James E.J. Bottomley", "Martin K. Petersen", Linus Torvalds
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.
Fixes: cbe193f6f093 ("scsi: ufs: Fix potential NULL pointer access during memcpy")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
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 064a44e628d6..6c251afe65f9 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c@@ -3418,9 +3418,11 @@ 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)