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[5.10/5.15] scsi: add a length check for VARIABLE_LENGTH_CMD commands

Message ID 20240321110229.9534-1-mish.uxin2012@yandex.ru
State New
Headers show
Series [5.10/5.15] scsi: add a length check for VARIABLE_LENGTH_CMD commands | expand

Commit Message

Mikhail Ukhin March 21, 2024, 11:02 a.m. UTC 
Fuzzing of 5.10 stable branch reports a slab-out-of-bounds error in
ata_scsi_pass_thru.

The error is fixed in 5.18 by commit
ce70fd9a551af7424a7dace2a1ba05a7de8eae27.
Backporting this commit would require significant changes to the code so
it is bettter to use a simple fix for that particular error.

The problem is that the length of the received SCSI command is not
validated if scsi_op == VARIABLE_LENGTH_CMD. It can lead to out-of-bounds
reading if the user sends a request with SCSI command of length less than
32.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Signed-off-by: Artem Sadovnikov <ancowi69@gmail.com>
Signed-off-by: Mikhail Ivanov <iwanov-23@bk.ru>
---
 drivers/ata/libata-scsi.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Damien Le Moal March 21, 2024, 11:53 p.m. UTC | #1 
On 3/21/24 20:02, Mikhail Ukhin wrote:
> Fuzzing of 5.10 stable branch reports a slab-out-of-bounds error in
> ata_scsi_pass_thru.
> 
> The error is fixed in 5.18 by commit
> ce70fd9a551af7424a7dace2a1ba05a7de8eae27.
> Backporting this commit would require significant changes to the code so
> it is bettter to use a simple fix for that particular error.
> 
> The problem is that the length of the received SCSI command is not
> validated if scsi_op == VARIABLE_LENGTH_CMD. It can lead to out-of-bounds
> reading if the user sends a request with SCSI command of length less than
> 32.
> 
> Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
> 
> Signed-off-by: Artem Sadovnikov <ancowi69@gmail.com>
> Signed-off-by: Mikhail Ivanov <iwanov-23@bk.ru>

Looks OK to me, but the patch title prefix is incorrect since this is not a scsi
patch. Please make that:

ata: libata-scsi: check cdb length for VARIABLE_LENGTH_CMD commands

> ---
>  drivers/ata/libata-scsi.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index dfa090ccd21c..77589e911d3d 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -4065,6 +4065,9 @@ int __ata_scsi_queuecmd(struct scsi_cmnd *scmd, struct ata_device *dev)
>  
>  	if (unlikely(!scmd->cmd_len))
>  		goto bad_cdb_len;
> +
> +	if (scsi_op == VARIABLE_LENGTH_CMD && scmd->cmd_len < 32)
> +		goto bad_cdb_len;
>  
>  	if (dev->class == ATA_DEV_ATA || dev->class == ATA_DEV_ZAC) {
>  		if (unlikely(scmd->cmd_len > dev->cdb_len))
diff mbox series

Patch

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index dfa090ccd21c..77589e911d3d 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -4065,6 +4065,9 @@  int __ata_scsi_queuecmd(struct scsi_cmnd *scmd, struct ata_device *dev)
 
 	if (unlikely(!scmd->cmd_len))
 		goto bad_cdb_len;
+
+	if (scsi_op == VARIABLE_LENGTH_CMD && scmd->cmd_len < 32)
+		goto bad_cdb_len;
 
 	if (dev->class == ATA_DEV_ATA || dev->class == ATA_DEV_ZAC) {
 		if (unlikely(scmd->cmd_len > dev->cdb_len))