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Commit 644a9d5e authored by Justin Tee's avatar Justin Tee Committed by Greg Kroah-Hartman
Browse files

scsi: lpfc: Prevent lpfc_debugfs_lockstat_write() buffer overflow 

[ Upstream commit c6087b82a9146826564a55c5ca0164cac40348f5 ]

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.

Link: https://lore.kernel.org/r/20230301231626.9621-2-justintee8345@gmail.com


Signed-off-by: default avatarJustin Tee <justin.tee@broadcom.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent c4813f85

drivers/scsi/lpfc/lpfc_debugfs.c

+5 −2
Original line number Diff line number Diff line
@@ -2046,6 +2046,7 @@ lpfc_debugfs_lockstat_write(struct file *file, const char __user *buf, 
	char mybuf[64];

	char *pbuf;

	int i;

	size_t bsize;



	/* Protect copy from user */

	if (!access_ok(buf, nbytes))
@@ -2053,7 +2054,9 @@ lpfc_debugfs_lockstat_write(struct file *file, const char __user *buf, 


	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];
@@ -2074,7 +2077,7 @@ lpfc_debugfs_lockstat_write(struct file *file, const char __user *buf, 
			qp->lock_conflict.wq_access = 0;

		}

	}

	return nbytes;

	return bsize;

}

#endif