On 6/6/24 6:34 AM, Mikhail Ukhin wrote:
No upstream commit exists for this patch.
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 ce70fd9a551a ("scsi: core: Remove the cmd field from struct scsi_request") upstream. 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 Signed-off-by: Mikhail Ukhin mish.uxin2012@yandex.ru
v2: The new addresses were added and the text was updated. v3: Checking has been moved to the function ata_scsi_var_len_cdb_xlat at the request of Damien Le Moal drivers/ata/libata-scsi.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index dfa090ccd21c..38488bd813d1 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -3948,7 +3948,11 @@ static unsigned int ata_scsi_var_len_cdb_xlat(struct ata_queued_cmd *qc) struct scsi_cmnd *scmd = qc->scsicmd; const u8 *cdb = scmd->cmnd; const u16 sa = get_unaligned_be16(&cdb[8]);
- u8 scsi_op = scmd->cmnd[0];
- if (scsi_op == VARIABLE_LENGTH_CMD && scmd->cmd_len < 32)
This functions is called only when the opcode is VARIABLE_LENGTH_CMD. So there is no need to check that again.
return 1;- /*
- if service action represents a ata pass-thru(32) command,
- then pass it to ata_scsi_pass_thru handler.