b209619f5b
Resolves CVE-2024-45775 CVE-2025-0624 Resolves: #RHEL-75735 Resolves: #RHEL-79837 Signed-off-by: Leo Sandoval <lsandova@redhat.com> Signed-off-by: Nicolas Frayer <nfrayer@redhat.com>
104 lines
3.2 KiB
Diff
104 lines
3.2 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
|
|
From: B Horn <b@horn.uk>
|
|
Date: Sun, 12 May 2024 03:26:19 +0100
|
|
Subject: [PATCH] disk/loopback: Reference tracking for the loopback
|
|
|
|
It was possible to delete a loopback while there were still references
|
|
to it. This led to an exploitable use-after-free.
|
|
|
|
Fixed by implementing a reference counting in the grub_loopback struct.
|
|
|
|
Reported-by: B Horn <b@horn.uk>
|
|
Signed-off-by: B Horn <b@horn.uk>
|
|
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
|
|
---
|
|
grub-core/disk/loopback.c | 18 ++++++++++++++++++
|
|
include/grub/err.h | 3 ++-
|
|
2 files changed, 20 insertions(+), 1 deletion(-)
|
|
|
|
diff --git a/grub-core/disk/loopback.c b/grub-core/disk/loopback.c
|
|
index 9406d931c..e7052a9cb 100644
|
|
--- a/grub-core/disk/loopback.c
|
|
+++ b/grub-core/disk/loopback.c
|
|
@@ -24,6 +24,7 @@
|
|
#include <grub/mm.h>
|
|
#include <grub/extcmd.h>
|
|
#include <grub/i18n.h>
|
|
+#include <grub/safemath.h>
|
|
|
|
GRUB_MOD_LICENSE ("GPLv3+");
|
|
|
|
@@ -33,6 +34,7 @@ struct grub_loopback
|
|
grub_file_t file;
|
|
struct grub_loopback *next;
|
|
unsigned long id;
|
|
+ grub_uint64_t refcnt;
|
|
};
|
|
|
|
static struct grub_loopback *loopback_list;
|
|
@@ -63,6 +65,8 @@ delete_loopback (const char *name)
|
|
if (! dev)
|
|
return grub_error (GRUB_ERR_BAD_DEVICE, "device not found");
|
|
|
|
+ if (dev->refcnt > 0)
|
|
+ return grub_error (GRUB_ERR_STILL_REFERENCED, "device still referenced");
|
|
/* Remove the device from the list. */
|
|
*prev = dev->next;
|
|
|
|
@@ -124,6 +128,7 @@ grub_cmd_loopback (grub_extcmd_context_t ctxt, int argc, char **args)
|
|
|
|
newdev->file = file;
|
|
newdev->id = last_id++;
|
|
+ newdev->refcnt = 0;
|
|
|
|
/* Add the new entry to the list. */
|
|
newdev->next = loopback_list;
|
|
@@ -165,6 +170,9 @@ grub_loopback_open (const char *name, grub_disk_t disk)
|
|
if (! dev)
|
|
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "can't open device");
|
|
|
|
+ if (grub_add (dev->refcnt, 1, &dev->refcnt))
|
|
+ grub_fatal ("Reference count overflow");
|
|
+
|
|
/* Use the filesize for the disk size, round up to a complete sector. */
|
|
if (dev->file->size != GRUB_FILE_SIZE_UNKNOWN)
|
|
disk->total_sectors = ((dev->file->size + GRUB_DISK_SECTOR_SIZE - 1)
|
|
@@ -182,6 +190,15 @@ grub_loopback_open (const char *name, grub_disk_t disk)
|
|
return 0;
|
|
}
|
|
|
|
+static void
|
|
+grub_loopback_close (grub_disk_t disk)
|
|
+{
|
|
+ struct grub_loopback *dev = disk->data;
|
|
+
|
|
+ if (grub_sub (dev->refcnt, 1, &dev->refcnt))
|
|
+ grub_fatal ("Reference count underflow");
|
|
+}
|
|
+
|
|
static grub_err_t
|
|
grub_loopback_read (grub_disk_t disk, grub_disk_addr_t sector,
|
|
grub_size_t size, char *buf)
|
|
@@ -224,6 +241,7 @@ static struct grub_disk_dev grub_loopback_dev =
|
|
.id = GRUB_DISK_DEVICE_LOOPBACK_ID,
|
|
.iterate = grub_loopback_iterate,
|
|
.open = grub_loopback_open,
|
|
+ .close = grub_loopback_close,
|
|
.read = grub_loopback_read,
|
|
.write = grub_loopback_write,
|
|
.next = 0
|
|
diff --git a/include/grub/err.h b/include/grub/err.h
|
|
index 9b830757d..1b5335610 100644
|
|
--- a/include/grub/err.h
|
|
+++ b/include/grub/err.h
|
|
@@ -71,7 +71,8 @@ typedef enum
|
|
GRUB_ERR_NET_PACKET_TOO_BIG,
|
|
GRUB_ERR_NET_NO_DOMAIN,
|
|
GRUB_ERR_EOF,
|
|
- GRUB_ERR_BAD_SIGNATURE
|
|
+ GRUB_ERR_BAD_SIGNATURE,
|
|
+ GRUB_ERR_STILL_REFERENCED
|
|
}
|
|
grub_err_t;
|
|
|