Messages in this thread Patch in this message | | | From | Oleksandr Natalenko <> | Subject | [PATCH 2/3] scsi: qedf: do not touch __user pointer in qedf_dbg_debug_cmd_read() directly | Date | Fri, 28 Jul 2023 08:58:18 +0200 |
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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 sprintf() and then calling simple_read_from_buffer() which does a proper copy_to_user() call.
Fixes: 61d8658b4a ("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.com/ Cc: Saurav Kashyap <skashyap@marvell.com> Cc: Rob Evers <revers@redhat.com> Cc: Johannes Thumshirn <Johannes.Thumshirn@wdc.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 Tested-by: Laurence Oberman <loberman@redhat.com> Signed-off-by: Oleksandr Natalenko <oleksandr@redhat.com> --- 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 4d1b99569d490..f910af0029a2c 100644 --- a/drivers/scsi/qedf/qedf_debugfs.c +++ b/drivers/scsi/qedf/qedf_debugfs.c @@ -138,15 +138,14 @@ qedf_dbg_debug_cmd_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos) { int cnt; + char cbuf[35]; 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 = sprintf(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 -- 2.41.0
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