On 6/27/24 06:13, 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 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.
This sentence is not needed in the commit message. That is a discussion to have when applying (or not) the patch.
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
Please send patches for libata to the ata maintainers (Niklas and myself). Use scripts/get_maintainer.pl And you will get our addresses and see that there is no need to spam Jens with libata patches.
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. v4: Extra opcode check removed. 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..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]);
- if (scmd->cmd_len < 32)
Given that the only service action supported is ATA_32, this check should be
if (scmd->cmd_len != 32
return 1;- /*
- if service action represents a ata pass-thru(32) command,
- then pass it to ata_scsi_pass_thru handler.
-- 2.25.1