[PATCH 0/5] scsi: ufs: Fix descriptor parsing and invalid input handling

[PATCH 0/5] scsi: ufs: Fix descriptor parsing and invalid input handling

[liqiang]

From: Li Qiang <liqiang01@kylinos.cn>

This series fixes five independently triggerable UFS robustness issues.

The first patch validates string descriptor payload sizes and avoids raw
descriptor overreads. The remaining patches protect command completion and
MCQ cleanup, validate connected lane counts, validate RPMB frame sizes before
parsing, and retain a NUL terminator for debugfs input.

The series was built with x86_64 defconfig plus UFS, RPMB, and debugfs.

Li Qiang (5):
  scsi: ufs: core: Validate string descriptors
  scsi: ufs: Fix NULL dereferences after tag lookup
  scsi: ufs: core: Validate connected lane counts
  scsi: ufs: rpmb: Validate frame before parsing
  scsi: ufs: debugfs: Reserve space for a string terminator

 drivers/ufs/core/ufs-debugfs.c |  2 +-
 drivers/ufs/core/ufs-mcq.c     |  6 ++++--
 drivers/ufs/core/ufs-rpmb.c    |  8 ++++++--
 drivers/ufs/core/ufshcd.c      | 35 +++++++++++++++++++++++++---------
 4 files changed, 37 insertions(+), 14 deletions(-)

-- 
2.43.0

[PATCH 1/5] scsi: ufs: core: Validate string descriptors

[liqiang]

From: Li Qiang <liqiang01@kylinos.cn>

The string descriptor length includes a two-byte header while the
UTF-16 payload starts after it. utf16s_to_utf8s() expects a count
of UTF-16 code units, not bytes. Passing the payload byte count can
make it read beyond the descriptor buffer.

Validate that the payload has an even byte count, pass a code-unit
count to the converter, and allocate sufficient UTF-8 output space.

The raw string buffer starts after the descriptor header but its size
is bLength. Copying bLength bytes from that pointer can read beyond
the response buffer.

Allocate a zeroed bLength-sized buffer and copy only the UTF-16
payload. This preserves the raw buffer size consumed by the RPMB
device-ID ABI while avoiding the overread.

Fixes: 4b828fe156a6 ("scsi: ufs: revamp string descriptor reading")
Fixes: d794b499f948 ("scsi: ufs: core: fix incorrect buffer duplication in ufshcd_read_string_desc()")
Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
---
 drivers/ufs/core/ufshcd.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index d3044a3089b5..3541da5b6f4d 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -3865,7 +3865,7 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index, u8 **buf, enum u
 {
 	struct uc_string_id *uc_str;
 	u8 *str;
-	int ret;
+	int ret, uc_len;
 
 	if (!buf)
 		return -EINVAL;
@@ -3890,11 +3890,19 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index, u8 **buf, enum u
 		goto out;
 	}
 
+	uc_len = uc_str->len - QUERY_DESC_HDR_SIZE;
+	if (uc_len % sizeof(*uc_str->uc)) {
+		dev_err(hba->dev, "String Desc has an odd UTF-16 payload length\n");
+		str = NULL;
+		ret = -EINVAL;
+		goto out;
+	}
+
 	if (fmt == SD_ASCII_STD) {
 		ssize_t ascii_len;
 		int i;
-		/* remove header and divide by 2 to move from UTF16 to UTF8 */
-		ascii_len = (uc_str->len - QUERY_DESC_HDR_SIZE) / 2 + 1;
+		/* Allow up to three UTF-8 bytes per UTF-16 code unit plus a NUL. */
+		ascii_len = uc_len / sizeof(*uc_str->uc) * 3 + 1;
 		str = kzalloc(ascii_len, GFP_KERNEL);
 		if (!str) {
 			ret = -ENOMEM;
@@ -3906,7 +3914,7 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index, u8 **buf, enum u
 		 * we need to convert to utf-8 so it can be displayed
 		 */
 		ret = utf16s_to_utf8s(uc_str->uc,
-				      uc_str->len - QUERY_DESC_HDR_SIZE,
+				      uc_len / sizeof(*uc_str->uc),
 				      UTF16_BIG_ENDIAN, str, ascii_len - 1);
 
 		/* replace non-printable or non-ASCII characters with spaces */
@@ -3916,11 +3924,17 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index, u8 **buf, enum u
 		str[ret++] = '\0';
 
 	} else {
-		str = kmemdup(uc_str->uc, uc_str->len, GFP_KERNEL);
+		/*
+		 * Keep the bLength-sized raw output for the RPMB device ID ABI.
+		 * The two bytes beyond the UTF-16 payload are explicitly zeroed
+		 * instead of being read past the descriptor buffer.
+		 */
+		str = kzalloc(uc_str->len, GFP_KERNEL);
 		if (!str) {
 			ret = -ENOMEM;
 			goto out;
 		}
+		memcpy(str, uc_str->uc, uc_len);
 		ret = uc_str->len;
 	}
 out:
-- 
2.43.0

Re: [PATCH 1/5] scsi: ufs: core: Validate string descriptors

[Bart Van Assche]

On 7/15/26 11:19 PM, liqiang wrote:
> @@ -3916,11 +3924,17 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index, u8 **buf, enum u
>   		str[ret++] = '\0';
>   
>   	} else {
> -		str = kmemdup(uc_str->uc, uc_str->len, GFP_KERNEL);
> +		/*
> +		 * Keep the bLength-sized raw output for the RPMB device ID ABI.
> +		 * The two bytes beyond the UTF-16 payload are explicitly zeroed
> +		 * instead of being read past the descriptor buffer.
> +		 */
> +		str = kzalloc(uc_str->len, GFP_KERNEL);
>   		if (!str) {
>   			ret = -ENOMEM;
>   			goto out;
>   		}
> +		memcpy(str, uc_str->uc, uc_len);
>   		ret = uc_str->len;
>   	}

The above code can be simplified by using kasprintf(GFP_KERNEL, "%.*s",
...), isn't it?

Thanks,

Bart.

Re: [PATCH 1/5] scsi: ufs: core: Validate string descriptors

[Li Qiang]

Hi Bart,

I don't think kasprintf() is suitable here. This path must preserve the raw UTF-16 bytes and return a buffer of uc_str->len bytes for the RPMB device-ID ABI; %.*s treats the data as a C string and would not preserve embedded NUL bytes or the required two-byte padding.

Thanks,
Li Qiang

[PATCH 2/5] scsi: ufs: Fix NULL dereferences after tag lookup

[liqiang]

From: Li Qiang <liqiang01@kylinos.cn>

ufshcd_tag_to_cmd() can return NULL when no command is associated
with a tag. The MCQ cleanup and completion paths dereferenced the
result before checking it.

Move private-command and request lookups after the NULL checks. Also
avoid dereferencing cqe while reporting an invalid tag because the
single-doorbell completion path passes a NULL CQE.

Fixes: 22089c218037 ("scsi: ufs: core: Optimize the hot path")
Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
---
 drivers/ufs/core/ufs-mcq.c | 6 ++++--
 drivers/ufs/core/ufshcd.c  | 7 ++++---
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
index 13b60a2d06db..15850b0658f9 100644
--- a/drivers/ufs/core/ufs-mcq.c
+++ b/drivers/ufs/core/ufs-mcq.c
@@ -555,8 +555,8 @@ static int ufshcd_mcq_sq_start(struct ufs_hba *hba, struct ufs_hw_queue *hwq)
 int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag)
 {
 	struct scsi_cmnd *cmd = ufshcd_tag_to_cmd(hba, task_tag);
-	struct ufshcd_lrb *lrbp = scsi_cmd_priv(cmd);
-	struct request *rq = scsi_cmd_to_rq(cmd);
+	struct ufshcd_lrb *lrbp;
+	struct request *rq;
 	struct ufs_hw_queue *hwq;
 	void __iomem *reg, *opr_sqd_base;
 	u32 nexus, id, val;
@@ -568,6 +568,8 @@ int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag)
 	if (!cmd)
 		return -EINVAL;
 
+	lrbp = scsi_cmd_priv(cmd);
+	rq = scsi_cmd_to_rq(cmd);
 	hwq = ufshcd_mcq_req_to_hwq(hba, rq);
 	if (!hwq)
 		return 0;
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 3541da5b6f4d..f2a5fa624e74 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -5857,13 +5857,14 @@ void ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag,
 			  struct cq_entry *cqe)
 {
 	struct scsi_cmnd *cmd = ufshcd_tag_to_cmd(hba, task_tag);
-	struct ufshcd_lrb *lrbp = scsi_cmd_priv(cmd);
+	struct ufshcd_lrb *lrbp;
 	enum utp_ocs ocs;
 
-	if (WARN_ONCE(!cmd, "cqe->command_desc_base_addr = %#llx\n",
-		      le64_to_cpu(cqe->command_desc_base_addr)))
+	if (WARN_ONCE(!cmd, "invalid completion tag %d, cqe->command_desc_base_addr = %#llx\n",
+		      task_tag, cqe ? le64_to_cpu(cqe->command_desc_base_addr) : 0ULL))
 		return;
 
+	lrbp = scsi_cmd_priv(cmd);
 	if (hba->monitor.enabled) {
 		lrbp->compl_time_stamp = ktime_get();
 		lrbp->compl_time_stamp_local_clock = local_clock();
-- 
2.43.0

Re: [PATCH 2/5] scsi: ufs: Fix NULL dereferences after tag lookup

[Bart Van Assche]

On 7/15/26 11:19 PM, liqiang wrote:
> diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
> index 13b60a2d06db..15850b0658f9 100644
> --- a/drivers/ufs/core/ufs-mcq.c
> +++ b/drivers/ufs/core/ufs-mcq.c
> @@ -555,8 +555,8 @@ static int ufshcd_mcq_sq_start(struct ufs_hba *hba, struct ufs_hw_queue *hwq)
>   int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag)
>   {
>   	struct scsi_cmnd *cmd = ufshcd_tag_to_cmd(hba, task_tag);
> -	struct ufshcd_lrb *lrbp = scsi_cmd_priv(cmd);
> -	struct request *rq = scsi_cmd_to_rq(cmd);
> +	struct ufshcd_lrb *lrbp;
> +	struct request *rq;
>   	struct ufs_hw_queue *hwq;
>   	void __iomem *reg, *opr_sqd_base;
>   	u32 nexus, id, val;
> @@ -568,6 +568,8 @@ int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag)
>   	if (!cmd)
>   		return -EINVAL;
>   
> +	lrbp = scsi_cmd_priv(cmd);
> +	rq = scsi_cmd_to_rq(cmd);
>   	hwq = ufshcd_mcq_req_to_hwq(hba, rq);
>   	if (!hwq)
>   		return 0;

Please drop this change. Calling scsi_cmd_priv(NULL) or
scsi_cmd_to_rq(NULL) is safe if the pointers returned by these functions
are not used.

> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 3541da5b6f4d..f2a5fa624e74 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -5857,13 +5857,14 @@ void ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag,
>   			  struct cq_entry *cqe)
>   {
>   	struct scsi_cmnd *cmd = ufshcd_tag_to_cmd(hba, task_tag);
> -	struct ufshcd_lrb *lrbp = scsi_cmd_priv(cmd);
> +	struct ufshcd_lrb *lrbp;
>   	enum utp_ocs ocs;

Same comment here: calling scsi_cmd_priv(NULL) is safe if the returned
pointer is not used as is the case here.

>   
> -	if (WARN_ONCE(!cmd, "cqe->command_desc_base_addr = %#llx\n",
> -		      le64_to_cpu(cqe->command_desc_base_addr)))
> +	if (WARN_ONCE(!cmd, "invalid completion tag %d, cqe->command_desc_base_addr = %#llx\n",
> +		      task_tag, cqe ? le64_to_cpu(cqe->command_desc_base_addr) : 0ULL))
>   		return;

The above change looks good to me.

Thanks,

Bart.

[PATCH 3/5] scsi: ufs: core: Validate connected lane counts

[liqiang]

From: Li Qiang <liqiang01@kylinos.cn>

The connected lane count is used by TX equalization code to index
arrays sized by UFS_MAX_LANES. Reject zero and out-of-range RX or TX
lane counts before they can be propagated.

Fixes: 03e5d38e2f98 ("scsi: ufs: core: Add support for TX Equalization")
Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
---
 drivers/ufs/core/ufshcd.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index f2a5fa624e74..1319e1071025 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -4729,7 +4729,9 @@ static int ufshcd_get_max_pwr_mode(struct ufs_hba *hba)
 	ufshcd_dme_get(hba, UIC_ARG_MIB(PA_CONNECTEDTXDATALANES),
 			&pwr_info->lane_tx);
 
-	if (!pwr_info->lane_rx || !pwr_info->lane_tx) {
+	if (!pwr_info->lane_rx || !pwr_info->lane_tx ||
+	    pwr_info->lane_rx > UFS_MAX_LANES ||
+	    pwr_info->lane_tx > UFS_MAX_LANES) {
 		dev_err(hba->dev, "%s: invalid connected lanes value. rx=%d, tx=%d\n",
 				__func__,
 				pwr_info->lane_rx,
-- 
2.43.0

[PATCH 4/5] scsi: ufs: rpmb: Validate frame before parsing

[liqiang]

From: Li Qiang <liqiang01@kylinos.cn>

The RPMB core only verifies that request and response buffers are
nonempty. This callback reads req_resp at the end of the first request
frame before validating the request length.

Require a complete frame before that access. Use unaligned accessors
because RPMB buffers are passed as u8 pointers and do not have an
alignment guarantee.

Fixes: b06b8c421485 ("scsi: ufs: core: Add OP-TEE based RPMB driver for UFS devices")
Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
---
 drivers/ufs/core/ufs-rpmb.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/ufs/core/ufs-rpmb.c b/drivers/ufs/core/ufs-rpmb.c
index ffad049872b9..53f66b274aca 100644
--- a/drivers/ufs/core/ufs-rpmb.c
+++ b/drivers/ufs/core/ufs-rpmb.c
@@ -69,7 +69,11 @@ static int ufs_rpmb_route_frames(struct device *dev, u8 *req, unsigned int req_l
 
 	hba = ufs_rpmb->hba;
 
-	req_type = be16_to_cpu(frm_out->req_resp);
+	/* req_resp is at the end of an RPMB frame. */
+	if (req_len < sizeof(*frm_out))
+		return -EINVAL;
+
+	req_type = get_unaligned_be16(&frm_out->req_resp);
 
 	switch (req_type) {
 	case RPMB_PROGRAM_KEY:
@@ -107,7 +111,7 @@ static int ufs_rpmb_route_frames(struct device *dev, u8 *req, unsigned int req_l
 		struct rpmb_frame *frm_resp = (struct rpmb_frame *)resp;
 
 		memset(frm_resp, 0, sizeof(*frm_resp));
-		frm_resp->req_resp = cpu_to_be16(RPMB_RESULT_READ);
+		put_unaligned_be16(RPMB_RESULT_READ, &frm_resp->req_resp);
 		ret = ufs_sec_submit(hba, protocol_id, resp, resp_len, true);
 		if (ret) {
 			dev_err(dev, "Result read request failed with ret=%d\n", ret);
-- 
2.43.0

Re: [PATCH 4/5] scsi: ufs: rpmb: Validate frame before parsing

[Bart Van Assche]

On 7/15/26 11:19 PM, liqiang wrote:
> From: Li Qiang <liqiang01@kylinos.cn>
> 
> The RPMB core only verifies that request and response buffers are
> nonempty. This callback reads req_resp at the end of the first request
> frame before validating the request length.
> 
> Require a complete frame before that access. Use unaligned accessors
> because RPMB buffers are passed as u8 pointers and do not have an
> alignment guarantee.
> 
> Fixes: b06b8c421485 ("scsi: ufs: core: Add OP-TEE based RPMB driver for UFS devices")
> Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
> ---
>   drivers/ufs/core/ufs-rpmb.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/ufs/core/ufs-rpmb.c b/drivers/ufs/core/ufs-rpmb.c
> index ffad049872b9..53f66b274aca 100644
> --- a/drivers/ufs/core/ufs-rpmb.c
> +++ b/drivers/ufs/core/ufs-rpmb.c
> @@ -69,7 +69,11 @@ static int ufs_rpmb_route_frames(struct device *dev, u8 *req, unsigned int req_l
>   
>   	hba = ufs_rpmb->hba;
>   
> -	req_type = be16_to_cpu(frm_out->req_resp);
> +	/* req_resp is at the end of an RPMB frame. */
> +	if (req_len < sizeof(*frm_out))
> +		return -EINVAL;
> +
> +	req_type = get_unaligned_be16(&frm_out->req_resp);
>   
>   	switch (req_type) {
>   	case RPMB_PROGRAM_KEY:
> @@ -107,7 +111,7 @@ static int ufs_rpmb_route_frames(struct device *dev, u8 *req, unsigned int req_l
>   		struct rpmb_frame *frm_resp = (struct rpmb_frame *)resp;
>   
>   		memset(frm_resp, 0, sizeof(*frm_resp));
> -		frm_resp->req_resp = cpu_to_be16(RPMB_RESULT_READ);
> +		put_unaligned_be16(RPMB_RESULT_READ, &frm_resp->req_resp);
>   		ret = ufs_sec_submit(hba, protocol_id, resp, resp_len, true);
>   		if (ret) {
>   			dev_err(dev, "Result read request failed with ret=%d\n", ret);

Please split this patch into two patches because the two above changes 
are independent of each other.

Thanks,

Bart.

[PATCH 5/5] scsi: ufs: debugfs: Reserve space for a string terminator

[liqiang]

From: Li Qiang <liqiang01@kylinos.cn>

ufs_saved_err_write() copies user input into a zero-initialized stack
buffer and passes it to kstrtoint(). A write that fills the entire
buffer overwrites its only terminator.

Reject an input whose length leaves no room for the trailing NUL.

Fixes: 7340faae9474 ("scsi: ufs: core: Add debugfs attributes for triggering the UFS EH")
Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
---
 drivers/ufs/core/ufs-debugfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufs-debugfs.c b/drivers/ufs/core/ufs-debugfs.c
index e3dd81d6fe82..be527209540d 100644
--- a/drivers/ufs/core/ufs-debugfs.c
+++ b/drivers/ufs/core/ufs-debugfs.c
@@ -165,7 +165,7 @@ static ssize_t ufs_saved_err_write(struct file *file, const char __user *buf,
 	char val_str[16] = { };
 	int val, ret;
 
-	if (count > sizeof(val_str))
+	if (count >= sizeof(val_str))
 		return -EINVAL;
 	if (copy_from_user(val_str, buf, count))
 		return -EFAULT;
-- 
2.43.0

Re: [PATCH 5/5] scsi: ufs: debugfs: Reserve space for a string terminator

[Bart Van Assche]

On 7/15/26 11:19 PM, liqiang wrote:
> From: Li Qiang <liqiang01@kylinos.cn>
> 
> ufs_saved_err_write() copies user input into a zero-initialized stack
> buffer and passes it to kstrtoint(). A write that fills the entire
> buffer overwrites its only terminator.
> 
> Reject an input whose length leaves no room for the trailing NUL.
> 
> Fixes: 7340faae9474 ("scsi: ufs: core: Add debugfs attributes for triggering the UFS EH")
> Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
> ---
>   drivers/ufs/core/ufs-debugfs.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/ufs/core/ufs-debugfs.c b/drivers/ufs/core/ufs-debugfs.c
> index e3dd81d6fe82..be527209540d 100644
> --- a/drivers/ufs/core/ufs-debugfs.c
> +++ b/drivers/ufs/core/ufs-debugfs.c
> @@ -165,7 +165,7 @@ static ssize_t ufs_saved_err_write(struct file *file, const char __user *buf,
>   	char val_str[16] = { };
>   	int val, ret;
>   
> -	if (count > sizeof(val_str))
> +	if (count >= sizeof(val_str))
>   		return -EINVAL;
>   	if (copy_from_user(val_str, buf, count))
>   		return -EFAULT;

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH 0/5] scsi: ufs: Fix descriptor parsing and invalid input handling

[Bart Van Assche]

On 7/15/26 11:19 PM, liqiang wrote:
> The first patch validates string descriptor payload sizes and avoids raw
> descriptor overreads. The remaining patches protect command completion and
> MCQ cleanup, validate connected lane counts, validate RPMB frame sizes before
> parsing, and retain a NUL terminator for debugfs input.
Since this is the first time that you are contributing to the UFS 
driver: how have these issues been discovered? How have these issues
been tested? Is my understanding correct that these only have been
compile-tested?

Bart.

Re: [PATCH 0/5] scsi: ufs: Fix descriptor parsing and invalid input handling

[Li Qiang]

Hi Bart,

These issues were discovered with the assistance of an AI-based static code analysis tool. After manual review, I confirmed that they are real issues, so I submitted patches to fix them.

I have not tested them on physical hardware. Since these patches do not change the main functionality and only add security hardening, I think compile testing is sufficient.

Thanks,
Li Qiang

[PATCH v2 0/6] scsi: ufs: Fix descriptor parsing and invalid input handling

[Li Qiang]

The first patch validates string descriptor payload sizes and avoids raw
descriptor overreads. The remaining patches protect invalid completion
diagnostics, validate connected lane counts, validate RPMB frame sizes,
use unaligned RPMB frame accesses, and retain a NUL terminator for
debugfs input.

Changes in v2:
- Reworked patch 2 as requested: drop changes to the safe
  scsi_cmd_priv(NULL) and scsi_cmd_to_rq(NULL) calls and retain only the
  invalid-CQE diagnostic fix.
- Split the previous RPMB patch into a request-length validation patch
  and an independent unaligned-access patch.

Li Qiang (6):
  scsi: ufs: core: Validate string descriptors
  scsi: ufs: Avoid NULL CQE dereference when reporting invalid tags
  scsi: ufs: core: Validate connected lane counts
  scsi: ufs: rpmb: Validate request frame length before parsing
  scsi: ufs: rpmb: Use unaligned accessors for RPMB frames
  scsi: ufs: debugfs: Reserve space for a string terminator

 drivers/ufs/core/ufs-debugfs.c |  2 +-
 drivers/ufs/core/ufs-rpmb.c    |  8 ++++++--
 drivers/ufs/core/ufshcd.c      | 32 ++++++++++++++++++++++++--------
 3 files changed, 31 insertions(+), 11 deletions(-)

-- 
2.43.0

[PATCH v2 1/6] scsi: ufs: core: Validate string descriptors

[Li Qiang]

The string descriptor length includes a two-byte header while the
UTF-16 payload starts after it. utf16s_to_utf8s() expects a count
of UTF-16 code units, not bytes. Passing the payload byte count can
make it read beyond the descriptor buffer.

Validate that the payload has an even byte count, pass a code-unit
count to the converter, and allocate sufficient UTF-8 output space.

The raw string buffer starts after the descriptor header but its size
is bLength. Copying bLength bytes from that pointer can read beyond
the response buffer.

Allocate a zeroed bLength-sized buffer and copy only the UTF-16
payload. This preserves the raw buffer size consumed by the RPMB
device-ID ABI while avoiding the overread.

Fixes: 4b828fe156a6 ("scsi: ufs: revamp string descriptor reading")
Fixes: d794b499f948 ("scsi: ufs: core: fix incorrect buffer duplication in ufshcd_read_string_desc()")
Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
---
 drivers/ufs/core/ufshcd.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index d3044a3089b5..3541da5b6f4d 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -3865,7 +3865,7 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index, u8 **buf, enum u
 {
 	struct uc_string_id *uc_str;
 	u8 *str;
-	int ret;
+	int ret, uc_len;
 
 	if (!buf)
 		return -EINVAL;
@@ -3890,11 +3890,19 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index, u8 **buf, enum u
 		goto out;
 	}
 
+	uc_len = uc_str->len - QUERY_DESC_HDR_SIZE;
+	if (uc_len % sizeof(*uc_str->uc)) {
+		dev_err(hba->dev, "String Desc has an odd UTF-16 payload length\n");
+		str = NULL;
+		ret = -EINVAL;
+		goto out;
+	}
+
 	if (fmt == SD_ASCII_STD) {
 		ssize_t ascii_len;
 		int i;
-		/* remove header and divide by 2 to move from UTF16 to UTF8 */
-		ascii_len = (uc_str->len - QUERY_DESC_HDR_SIZE) / 2 + 1;
+		/* Allow up to three UTF-8 bytes per UTF-16 code unit plus a NUL. */
+		ascii_len = uc_len / sizeof(*uc_str->uc) * 3 + 1;
 		str = kzalloc(ascii_len, GFP_KERNEL);
 		if (!str) {
 			ret = -ENOMEM;
@@ -3906,7 +3914,7 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index, u8 **buf, enum u
 		 * we need to convert to utf-8 so it can be displayed
 		 */
 		ret = utf16s_to_utf8s(uc_str->uc,
-				      uc_str->len - QUERY_DESC_HDR_SIZE,
+				      uc_len / sizeof(*uc_str->uc),
 				      UTF16_BIG_ENDIAN, str, ascii_len - 1);
 
 		/* replace non-printable or non-ASCII characters with spaces */
@@ -3916,11 +3924,17 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index, u8 **buf, enum u
 		str[ret++] = '\0';
 
 	} else {
-		str = kmemdup(uc_str->uc, uc_str->len, GFP_KERNEL);
+		/*
+		 * Keep the bLength-sized raw output for the RPMB device ID ABI.
+		 * The two bytes beyond the UTF-16 payload are explicitly zeroed
+		 * instead of being read past the descriptor buffer.
+		 */
+		str = kzalloc(uc_str->len, GFP_KERNEL);
 		if (!str) {
 			ret = -ENOMEM;
 			goto out;
 		}
+		memcpy(str, uc_str->uc, uc_len);
 		ret = uc_str->len;
 	}
 out:
-- 
2.43.0

[PATCH v2 2/6] scsi: ufs: Avoid NULL CQE dereference when reporting invalid tags

[Li Qiang]

The single-doorbell completion path can call ufshcd_compl_one_cqe() with

a NULL CQE. If no command is associated with the completion tag, the

warning message dereferences the CQE while reporting the error.

Avoid that dereference and include the invalid tag in the warning.

Fixes: 22089c218037 ("scsi: ufs: core: Optimize the hot path")
Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
---
 drivers/ufs/core/ufshcd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 3541da5b6f4d..d1b989abc9e2 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -5860,8 +5860,8 @@ void ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag,
 	struct ufshcd_lrb *lrbp = scsi_cmd_priv(cmd);
 	enum utp_ocs ocs;
 
-	if (WARN_ONCE(!cmd, "cqe->command_desc_base_addr = %#llx\n",
-		      le64_to_cpu(cqe->command_desc_base_addr)))
+	if (WARN_ONCE(!cmd, "invalid completion tag %d, cqe->command_desc_base_addr = %#llx\n",
+		      task_tag, cqe ? le64_to_cpu(cqe->command_desc_base_addr) : 0ULL))
 		return;
 
 	if (hba->monitor.enabled) {
-- 
2.43.0

[PATCH v2 3/6] scsi: ufs: core: Validate connected lane counts

[Li Qiang]

The connected lane count is used by TX equalization code to index
arrays sized by UFS_MAX_LANES. Reject zero and out-of-range RX or TX
lane counts before they can be propagated.

Fixes: 03e5d38e2f98 ("scsi: ufs: core: Add support for TX Equalization")
Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
---
 drivers/ufs/core/ufshcd.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index d1b989abc9e2..bbadddcd661a 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -4729,7 +4729,9 @@ static int ufshcd_get_max_pwr_mode(struct ufs_hba *hba)
 	ufshcd_dme_get(hba, UIC_ARG_MIB(PA_CONNECTEDTXDATALANES),
 			&pwr_info->lane_tx);
 
-	if (!pwr_info->lane_rx || !pwr_info->lane_tx) {
+	if (!pwr_info->lane_rx || !pwr_info->lane_tx ||
+	    pwr_info->lane_rx > UFS_MAX_LANES ||
+	    pwr_info->lane_tx > UFS_MAX_LANES) {
 		dev_err(hba->dev, "%s: invalid connected lanes value. rx=%d, tx=%d\n",
 				__func__,
 				pwr_info->lane_rx,
-- 
2.43.0

[PATCH v2 4/6] scsi: ufs: rpmb: Validate request frame length before parsing

[Li Qiang]

The RPMB core only verifies that request and response buffers are

nonempty. This callback reads req_resp at the end of the first request

frame before validating the request length.

Require a complete frame before that access.

Fixes: b06b8c421485 ("scsi: ufs: core: Add OP-TEE based RPMB driver for UFS devices")
Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
---
 drivers/ufs/core/ufs-rpmb.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/ufs/core/ufs-rpmb.c b/drivers/ufs/core/ufs-rpmb.c
index ffad049872b9..431f85b36876 100644
--- a/drivers/ufs/core/ufs-rpmb.c
+++ b/drivers/ufs/core/ufs-rpmb.c
@@ -69,6 +69,10 @@ static int ufs_rpmb_route_frames(struct device *dev, u8 *req, unsigned int req_l
 
 	hba = ufs_rpmb->hba;
 
+	/* req_resp is at the end of an RPMB frame. */
+	if (req_len < sizeof(*frm_out))
+		return -EINVAL;
+
 	req_type = be16_to_cpu(frm_out->req_resp);
 
 	switch (req_type) {
-- 
2.43.0

[PATCH v2 5/6] scsi: ufs: rpmb: Use unaligned accessors for RPMB frames

[Li Qiang]

RPMB frame buffers are passed as u8 pointers and do not have an

alignment guarantee. Use unaligned accessors for the req_resp field.

Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
---
 drivers/ufs/core/ufs-rpmb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/ufs/core/ufs-rpmb.c b/drivers/ufs/core/ufs-rpmb.c
index 431f85b36876..53f66b274aca 100644
--- a/drivers/ufs/core/ufs-rpmb.c
+++ b/drivers/ufs/core/ufs-rpmb.c
@@ -73,7 +73,7 @@ static int ufs_rpmb_route_frames(struct device *dev, u8 *req, unsigned int req_l
 	if (req_len < sizeof(*frm_out))
 		return -EINVAL;
 
-	req_type = be16_to_cpu(frm_out->req_resp);
+	req_type = get_unaligned_be16(&frm_out->req_resp);
 
 	switch (req_type) {
 	case RPMB_PROGRAM_KEY:
@@ -111,7 +111,7 @@ static int ufs_rpmb_route_frames(struct device *dev, u8 *req, unsigned int req_l
 		struct rpmb_frame *frm_resp = (struct rpmb_frame *)resp;
 
 		memset(frm_resp, 0, sizeof(*frm_resp));
-		frm_resp->req_resp = cpu_to_be16(RPMB_RESULT_READ);
+		put_unaligned_be16(RPMB_RESULT_READ, &frm_resp->req_resp);
 		ret = ufs_sec_submit(hba, protocol_id, resp, resp_len, true);
 		if (ret) {
 			dev_err(dev, "Result read request failed with ret=%d\n", ret);
-- 
2.43.0

[PATCH v2 6/6] scsi: ufs: debugfs: Reserve space for a string terminator

[Li Qiang]

ufs_saved_err_write() copies user input into a zero-initialized stack
buffer and passes it to kstrtoint(). A write that fills the entire
buffer overwrites its only terminator.

Reject an input whose length leaves no room for the trailing NUL.

Fixes: 7340faae9474 ("scsi: ufs: core: Add debugfs attributes for triggering the UFS EH")
Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
---
 drivers/ufs/core/ufs-debugfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufs-debugfs.c b/drivers/ufs/core/ufs-debugfs.c
index e3dd81d6fe82..be527209540d 100644
--- a/drivers/ufs/core/ufs-debugfs.c
+++ b/drivers/ufs/core/ufs-debugfs.c
@@ -165,7 +165,7 @@ static ssize_t ufs_saved_err_write(struct file *file, const char __user *buf,
 	char val_str[16] = { };
 	int val, ret;
 
-	if (count > sizeof(val_str))
+	if (count >= sizeof(val_str))
 		return -EINVAL;
 	if (copy_from_user(val_str, buf, count))
 		return -EFAULT;
-- 
2.43.0