This is a note to let you know that I've just added the patch titled
scsi: lpfc: Prevent lpfc_debugfs_lockstat_write() buffer overflow
to the 6.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
scsi-lpfc-prevent-lpfc_debugfs_lockstat_write-buffer.patch
and it can be found in the queue-6.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6ea0206e4441b40e5aa8dd36ee7465378195c8d1
Author: Justin Tee <justin.tee@xxxxxxxxxxxx>
Date: Wed Mar 1 15:16:17 2023 -0800
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@xxxxxxxxx
Signed-off-by: Justin Tee <justin.tee@xxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/scsi/lpfc/lpfc_debugfs.c b/drivers/scsi/lpfc/lpfc_debugfs.c
index f5252e45a48a2..3e365e5e194a2 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
