From: Simon Richter <Simon.Richter@hogyros.de>
Date: Sat, 7 Mar 2026 17:35:34 +0000 (+0900)
Subject: PCI/VGA: Pass vga_get_uninterruptible() errors to userspace
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=2a93c9851b2bb38614fadd84aa674b7a5c8181c6;p=thirdparty%2Flinux.git

PCI/VGA: Pass vga_get_uninterruptible() errors to userspace

If VGA routing cannot be established, vga_get_uninterruptible() returns an
error and does not increment the lock count. Return the error to the
caller.

Return before incrementing uc->io_cnt/mem_cnt so vga_arb_release() won't
call vga_put() when userspace closes the handle.

Signed-off-by: Simon Richter <Simon.Richter@hogyros.de>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260307173538.763188-2-Simon.Richter@hogyros.de
---

diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
index d9383bf541e7c..22b2b6ebdefdb 100644
--- a/drivers/pci/vgaarb.c
+++ b/drivers/pci/vgaarb.c
@@ -1134,6 +1134,7 @@ static ssize_t vga_arb_write(struct file *file, const char __user *buf,
 	char kbuf[64], *curr_pos;
 	size_t remaining = count;
 
+	int err;
 	int ret_val;
 	int i;
 
@@ -1165,7 +1166,11 @@ static ssize_t vga_arb_write(struct file *file, const char __user *buf,
 			goto done;
 		}
 
-		vga_get_uninterruptible(pdev, io_state);
+		err = vga_get_uninterruptible(pdev, io_state);
+		if (err) {
+			ret_val = err;
+			goto done;
+		}
 
 		/* Update the client's locks lists */
 		for (i = 0; i < MAX_USER_CARDS; i++) {