5.4-stable review patch. If anyone has any objections, please let me know.
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From: Oleksandr Natalenko oleksandr@redhat.com
[ Upstream commit 31b5991a9a91ba97237ac9da509d78eec453ff72 ]
The qedf_dbg_debug_cmd_read() function invokes sprintf() directly on a __user pointer, which may crash the kernel.
Avoid doing that by using a small on-stack 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/20230731084034.37021-3-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_debugfs.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/qedf/qedf_debugfs.c b/drivers/scsi/qedf/qedf_debugfs.c index 88378a277a015..5e638732d6852 100644 --- a/drivers/scsi/qedf/qedf_debugfs.c +++ b/drivers/scsi/qedf/qedf_debugfs.c @@ -140,15 +140,14 @@ qedf_dbg_debug_cmd_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos) { int cnt; + char cbuf[32]; struct qedf_dbg_ctx *qedf_dbg = (struct qedf_dbg_ctx *)filp->private_data;
QEDF_INFO(qedf_dbg, QEDF_LOG_DEBUGFS, "debug mask=0x%x\n", qedf_debug); - cnt = sprintf(buffer, "debug mask = 0x%x\n", qedf_debug); + cnt = scnprintf(cbuf, sizeof(cbuf), "debug mask = 0x%x\n", qedf_debug);
- cnt = min_t(int, count, cnt - *ppos); - *ppos += cnt; - return cnt; + return simple_read_from_buffer(buffer, count, ppos, cbuf, cnt); }
static ssize_t