linux-kernel - [PATCH AUTOSEL 5.10 105/114] scsi: st: Restore some drive settings after reset

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250505231817.2697367-105-sashal@kernel.org>
Date: Mon,  5 May 2025 19:18:08 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Kai Mäkisara <Kai.Makisara@...umbus.fi>,
	John Meneghini <jmeneghi@...hat.com>,
	"Martin K . Petersen" <martin.petersen@...cle.com>,
	Sasha Levin <sashal@...nel.org>,
	James.Bottomley@...senPartnership.com,
	linux-scsi@...r.kernel.org
Subject: [PATCH AUTOSEL 5.10 105/114] scsi: st: Restore some drive settings after reset

From: Kai Mäkisara <Kai.Makisara@...umbus.fi>

[ Upstream commit 7081dc75df79696d8322d01821c28e53416c932c ]

Some of the allowed operations put the tape into a known position to
continue operation assuming only the tape position has changed.  But reset
sets partition, density and block size to drive default values. These
should be restored to the values before reset.

Normally the current block size and density are stored by the drive.  If
the settings have been changed, the changed values have to be saved by the
driver across reset.

Signed-off-by: Kai Mäkisara <Kai.Makisara@...umbus.fi>
Link: https://lore.kernel.org/r/20250120194925.44432-2-Kai.Makisara@kolumbus.fi
Reviewed-by: John Meneghini <jmeneghi@...hat.com>
Tested-by: John Meneghini <jmeneghi@...hat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@...cle.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/scsi/st.c | 24 +++++++++++++++++++++---
 drivers/scsi/st.h |  2 ++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 747e69abfcfce..23bbb062c2aaa 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -951,7 +951,6 @@ static void reset_state(struct scsi_tape *STp)
 		STp->partition = find_partition(STp);
 		if (STp->partition < 0)
 			STp->partition = 0;
-		STp->new_partition = STp->partition;
 	}
 }
 .
@@ -2921,14 +2920,17 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
 		if (cmd_in == MTSETDENSITY) {
 			(STp->buffer)->b_data[4] = arg;
 			STp->density_changed = 1;	/* At least we tried ;-) */
+			STp->changed_density = arg;
 		} else if (cmd_in == SET_DENS_AND_BLK)
 			(STp->buffer)->b_data[4] = arg >> 24;
 		else
 			(STp->buffer)->b_data[4] = STp->density;
 		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
 			ltmp = arg & MT_ST_BLKSIZE_MASK;
-			if (cmd_in == MTSETBLK)
+			if (cmd_in == MTSETBLK) {
 				STp->blksize_changed = 1; /* At least we tried ;-) */
+				STp->changed_blksize = arg;
+			}
 		} else
 			ltmp = STp->block_size;
 		(STp->buffer)->b_data[9] = (ltmp >> 16);
@@ -3628,9 +3630,25 @@ static long st_ioctl_common(struct file *file, unsigned int cmd_in, void __user
 				retval = (-EIO);
 				goto out;
 			}
-			reset_state(STp);
+			reset_state(STp); /* Clears pos_unknown */
 			/* remove this when the midlevel properly clears was_reset */
 			STp->device->was_reset = 0;
+
+			/* Fix the device settings after reset, ignore errors */
+			if (mtc.mt_op == MTREW || mtc.mt_op == MTSEEK ||
+				mtc.mt_op == MTEOM) {
+				if (STp->can_partitions) {
+					/* STp->new_partition contains the
+					 *  latest partition set
+					 */
+					STp->partition = 0;
+					switch_partition(STp);
+				}
+				if (STp->density_changed)
+					st_int_ioctl(STp, MTSETDENSITY, STp->changed_density);
+				if (STp->blksize_changed)
+					st_int_ioctl(STp, MTSETBLK, STp->changed_blksize);
+			}
 		}
 
 		if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK &&
diff --git a/drivers/scsi/st.h b/drivers/scsi/st.h
index 95d2e7a7988de..c9947abb0a451 100644
--- a/drivers/scsi/st.h
+++ b/drivers/scsi/st.h
@@ -168,12 +168,14 @@ struct scsi_tape {
 	unsigned char compression_changed;
 	unsigned char drv_buffer;
 	unsigned char density;
+	unsigned char changed_density;
 	unsigned char door_locked;
 	unsigned char autorew_dev;   /* auto-rewind device */
 	unsigned char rew_at_close;  /* rewind necessary at close */
 	unsigned char inited;
 	unsigned char cleaning_req;  /* cleaning requested? */
 	int block_size;
+	int changed_blksize;
 	int min_block;
 	int max_block;
 	int recover_count;     /* From tape opening */
-- 
2.39.5