A static code analysis tool flagged the possibility of buffer overflow when using copy_from_user for a debugfs entry. Currently, it is possible that copy_from_user copies more bytes than what would fit in the mybuf char array. Add a min restriction check between sizeof(mybuf) - 1 and nbytes passed from the userspace buffer to protect against buffer overflow. Signed-off-by: Justin Tee <justin.tee@xxxxxxxxxxxx> --- drivers/scsi/lpfc/lpfc_debugfs.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_debugfs.c b/drivers/scsi/lpfc/lpfc_debugfs.c index f5252e45a48a..3e365e5e194a 100644 --- a/drivers/scsi/lpfc/lpfc_debugfs.c +++ b/drivers/scsi/lpfc/lpfc_debugfs.c @@ -2157,10 +2157,13 @@ lpfc_debugfs_lockstat_write(struct file *file, const char __user *buf, char mybuf[64]; char *pbuf; int i; + size_t bsize; memset(mybuf, 0, sizeof(mybuf)); - if (copy_from_user(mybuf, buf, nbytes)) + bsize = min(nbytes, (sizeof(mybuf) - 1)); + + if (copy_from_user(mybuf, buf, bsize)) return -EFAULT; pbuf = &mybuf[0]; @@ -2181,7 +2184,7 @@ lpfc_debugfs_lockstat_write(struct file *file, const char __user *buf, qp->lock_conflict.wq_access = 0; } } - return nbytes; + return bsize; } #endif -- 2.38.0
