4.14-stable patches

added patches:
	vc_screen-reload-load-of-struct-vc_data-pointer-in-vcs_write-to-avoid-uaf.patch

diff --git a/queue-4.14/series b/queue-4.14/series
index 476681d3d299c3db8bfeb25e4fa34ba1a36d6e0c..9269b0f97f15f3a3a8105e17f6b802e2533aee4e 100644 (file)
--- a/queue-4.14/series
+++ b/queue-4.14/series
@@ -28,3 +28,4 @@ ata-libata-core-fix-ata_port_request_pm-locking.patch
 ata-libata-core-fix-port-and-device-removal.patch
 ata-libata-sata-increase-pmp-srst-timeout-to-10s.patch
 fs-binfmt_elf_efpic-fix-personality-for-elf-fdpic.patch
+vc_screen-reload-load-of-struct-vc_data-pointer-in-vcs_write-to-avoid-uaf.patch

diff --git a/queue-4.14/vc_screen-reload-load-of-struct-vc_data-pointer-in-vcs_write-to-avoid-uaf.patch b/queue-4.14/vc_screen-reload-load-of-struct-vc_data-pointer-in-vcs_write-to-avoid-uaf.patch
new file mode 100644 (file)
index 0000000..8492348
--- /dev/null
+++ b/queue-4.14/vc_screen-reload-load-of-struct-vc_data-pointer-in-vcs_write-to-avoid-uaf.patch
@@ -0,0 +1,117 @@
+From 8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357 Mon Sep 17 00:00:00 2001
+From: George Kennedy <george.kennedy@oracle.com>
+Date: Fri, 12 May 2023 06:08:48 -0500
+Subject: vc_screen: reload load of struct vc_data pointer in vcs_write() to avoid UAF
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: George Kennedy <george.kennedy@oracle.com>
+
+commit 8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357 upstream.
+
+After a call to console_unlock() in vcs_write() the vc_data struct can be
+freed by vc_port_destruct(). Because of that, the struct vc_data pointer
+must be reloaded in the while loop in vcs_write() after console_lock() to
+avoid a UAF when vcs_size() is called.
+
+Syzkaller reported a UAF in vcs_size().
+
+BUG: KASAN: slab-use-after-free in vcs_size (drivers/tty/vt/vc_screen.c:215)
+Read of size 4 at addr ffff8880beab89a8 by task repro_vcs_size/4119
+
+Call Trace:
+ <TASK>
+__asan_report_load4_noabort (mm/kasan/report_generic.c:380)
+vcs_size (drivers/tty/vt/vc_screen.c:215)
+vcs_write (drivers/tty/vt/vc_screen.c:664)
+vfs_write (fs/read_write.c:582 fs/read_write.c:564)
+...
+ <TASK>
+
+Allocated by task 1213:
+kmalloc_trace (mm/slab_common.c:1064)
+vc_allocate (./include/linux/slab.h:559 ./include/linux/slab.h:680
+    drivers/tty/vt/vt.c:1078 drivers/tty/vt/vt.c:1058)
+con_install (drivers/tty/vt/vt.c:3334)
+tty_init_dev (drivers/tty/tty_io.c:1303 drivers/tty/tty_io.c:1415
+    drivers/tty/tty_io.c:1392)
+tty_open (drivers/tty/tty_io.c:2082 drivers/tty/tty_io.c:2128)
+chrdev_open (fs/char_dev.c:415)
+do_dentry_open (fs/open.c:921)
+vfs_open (fs/open.c:1052)
+...
+
+Freed by task 4116:
+kfree (mm/slab_common.c:1016)
+vc_port_destruct (drivers/tty/vt/vt.c:1044)
+tty_port_destructor (drivers/tty/tty_port.c:296)
+tty_port_put (drivers/tty/tty_port.c:312)
+vt_disallocate_all (drivers/tty/vt/vt_ioctl.c:662 (discriminator 2))
+vt_ioctl (drivers/tty/vt/vt_ioctl.c:903)
+tty_ioctl (drivers/tty/tty_io.c:2778)
+...
+
+The buggy address belongs to the object at ffff8880beab8800
+ which belongs to the cache kmalloc-1k of size 1024
+The buggy address is located 424 bytes inside of
+ freed 1024-byte region [ffff8880beab8800, ffff8880beab8c00)
+
+The buggy address belongs to the physical page:
+page:00000000afc77580 refcount:1 mapcount:0 mapping:0000000000000000
+    index:0x0 pfn:0xbeab8
+head:00000000afc77580 order:3 entire_mapcount:0 nr_pages_mapped:0
+    pincount:0
+flags: 0xfffffc0010200(slab|head|node=0|zone=1|lastcpupid=0x1fffff)
+page_type: 0xffffffff()
+raw: 000fffffc0010200 ffff888100042dc0 ffffea000426de00 dead000000000002
+raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
+page dumped because: kasan: bad access detected
+
+Memory state around the buggy address:
+ ffff8880beab8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
+ ffff8880beab8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
+>ffff8880beab8980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
+                                  ^
+ ffff8880beab8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
+ ffff8880beab8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
+==================================================================
+Disabling lock debugging due to kernel taint
+
+Fixes: ac751efa6a0d ("console: rename acquire/release_console_sem() to console_lock/unlock()")
+Cc: stable <stable@kernel.org>
+Reported-by: syzkaller <syzkaller@googlegroups.com>
+Signed-off-by: George Kennedy <george.kennedy@oracle.com>
+Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
+Link: https://lore.kernel.org/r/1683889728-10411-1-git-send-email-george.kennedy@oracle.com
+[ Adjust context due to missing commit
+  71d4abfab322 ("vc_screen: rewrite vcs_size to accept vc, not inode")
+  in 4.14.y stable ]
+Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/tty/vt/vc_screen.c |   11 +++++++++--
+ 1 file changed, 9 insertions(+), 2 deletions(-)
+
+--- a/drivers/tty/vt/vc_screen.c
++++ b/drivers/tty/vt/vc_screen.c
+@@ -437,10 +437,17 @@ vcs_write(struct file *file, const char
+                       }
+               }
+ 
+-              /* The vcs_size might have changed while we slept to grab
+-               * the user buffer, so recheck.
++              /* The vc might have been freed or vcs_size might have changed
++               * while we slept to grab the user buffer, so recheck.
+                * Return data written up to now on failure.
+                */
++              vc = vcs_vc(inode, &viewed);
++              if (!vc) {
++                      if (written)
++                              break;
++                      ret = -ENXIO;
++                      goto unlock_out;
++              }
+               size = vcs_size(inode);
+               if (size < 0) {
+                       if (written)