4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Oleksandr Natalenko oleksandr@redhat.com
[ Upstream commit 25dbc20deab5165f847b4eb42f376f725a986ee8 ]
The qedf_dbg_fp_int_cmd_read() function invokes sprintf() directly on a __user pointer, which may crash the kernel.
Avoid doing that by vmalloc()'ating a buffer for scnprintf() and then calling simple_read_from_buffer() which does a proper copy_to_user() call.
Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.") Link: https://lore.kernel.org/lkml/20230724120241.40495-1-oleksandr@redhat.com/ Link: https://lore.kernel.org/linux-scsi/20230726101236.11922-1-skashyap@marvell.c... Cc: Saurav Kashyap skashyap@marvell.com Cc: Rob Evers revers@redhat.com Cc: Johannes Thumshirn Johannes.Thumshirn@wdc.com Cc: David Laight David.Laight@ACULAB.COM Cc: Jozef Bacik jobacik@redhat.com Cc: Laurence Oberman loberman@redhat.com Cc: "James E.J. Bottomley" jejb@linux.ibm.com Cc: "Martin K. Petersen" martin.petersen@oracle.com Cc: GR-QLogic-Storage-Upstream@marvell.com Cc: linux-scsi@vger.kernel.org Reviewed-by: Laurence Oberman loberman@redhat.com Reviewed-by: Johannes Thumshirn johannes.thumshirn@wdc.com Tested-by: Laurence Oberman loberman@redhat.com Acked-by: Saurav Kashyap skashyap@marvell.com Signed-off-by: Oleksandr Natalenko oleksandr@redhat.com Link: https://lore.kernel.org/r/20230731084034.37021-4-oleksandr@redhat.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/qedf/qedf_dbg.h | 2 ++ drivers/scsi/qedf/qedf_debugfs.c | 21 +++++++++++++++------ 2 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/drivers/scsi/qedf/qedf_dbg.h b/drivers/scsi/qedf/qedf_dbg.h index 50083cae84c37..9fa5da44971a4 100644 --- a/drivers/scsi/qedf/qedf_dbg.h +++ b/drivers/scsi/qedf/qedf_dbg.h @@ -63,6 +63,8 @@ extern uint qedf_debug; #define QEDF_LOG_NOTICE 0x40000000 /* Notice logs */ #define QEDF_LOG_WARN 0x80000000 /* Warning logs */
+#define QEDF_DEBUGFS_LOG_LEN (2 * PAGE_SIZE) + /* Debug context structure */ struct qedf_dbg_ctx { unsigned int host_no; diff --git a/drivers/scsi/qedf/qedf_debugfs.c b/drivers/scsi/qedf/qedf_debugfs.c index 273dd258a0022..41fa846f0bdb7 100644 --- a/drivers/scsi/qedf/qedf_debugfs.c +++ b/drivers/scsi/qedf/qedf_debugfs.c @@ -11,6 +11,7 @@ #include <linux/uaccess.h> #include <linux/debugfs.h> #include <linux/module.h> +#include <linux/vmalloc.h>
#include "qedf.h" #include "qedf_dbg.h" @@ -117,7 +118,9 @@ static ssize_t qedf_dbg_fp_int_cmd_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos) { + ssize_t ret; size_t cnt = 0; + char *cbuf; int id; struct qedf_fastpath *fp = NULL; struct qedf_dbg_ctx *qedf_dbg = @@ -127,19 +130,25 @@ qedf_dbg_fp_int_cmd_read(struct file *filp, char __user *buffer, size_t count,
QEDF_INFO(qedf_dbg, QEDF_LOG_DEBUGFS, "entered\n");
- cnt = sprintf(buffer, "\nFastpath I/O completions\n\n"); + cbuf = vmalloc(QEDF_DEBUGFS_LOG_LEN); + if (!cbuf) + return 0; + + cnt += scnprintf(cbuf + cnt, QEDF_DEBUGFS_LOG_LEN - cnt, "\nFastpath I/O completions\n\n");
for (id = 0; id < qedf->num_queues; id++) { fp = &(qedf->fp_array[id]); if (fp->sb_id == QEDF_SB_ID_NULL) continue; - cnt += sprintf((buffer + cnt), "#%d: %lu\n", id, - fp->completions); + cnt += scnprintf(cbuf + cnt, QEDF_DEBUGFS_LOG_LEN - cnt, + "#%d: %lu\n", id, fp->completions); }
- cnt = min_t(int, count, cnt - *ppos); - *ppos += cnt; - return cnt; + ret = simple_read_from_buffer(buffer, count, ppos, cbuf, cnt); + + vfree(cbuf); + + return ret; }
static ssize_t