================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:381 [inline] BUG: KASAN: slab-out-of-bounds in scr_memcpyw include/linux/vt_buffer.h:49 [inline] BUG: KASAN: slab-out-of-bounds in vc_do_resize+0x888/0x1340 drivers/tty/vt/vt.c:1274 Read of size 2 at addr ffff8880a666276c by task syz-executor.3/12113 CPU: 0 PID: 12113 Comm: syz-executor.3 Not tainted 5.7.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:382 __kasan_report.cold+0x35/0x4d mm/kasan/report.c:511 kasan_report+0x33/0x50 mm/kasan/common.c:625 check_memory_region_inline mm/kasan/generic.c:187 [inline] check_memory_region+0x141/0x190 mm/kasan/generic.c:193 memcpy+0x20/0x60 mm/kasan/common.c:106 memcpy include/linux/string.h:381 [inline] scr_memcpyw include/linux/vt_buffer.h:49 [inline] vc_do_resize+0x888/0x1340 drivers/tty/vt/vt.c:1274 fbcon_modechanged+0x36e/0x790 drivers/video/fbdev/core/fbcon.c:2989 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3047 fb_set_var+0xad0/0xd40 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x390/0x6e0 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f7619b69c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e46c0 RCX: 000000000045c829 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000008 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002f0 R14: 00000000004c5497 R15: 00007f7619b6a6d4 Allocated by task 12113: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x161/0x7a0 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] kzalloc include/linux/slab.h:669 [inline] vc_do_resize+0x245/0x1340 drivers/tty/vt/vt.c:1211 fbcon_modechanged+0x36e/0x790 drivers/video/fbdev/core/fbcon.c:2989 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3047 fb_set_var+0xad0/0xd40 drivers/video/fbdev/core/fbmem.c:1056 fbcon_resize+0x60c/0x6d0 drivers/video/fbdev/core/fbcon.c:2231 resize_screen drivers/tty/vt/vt.c:1150 [inline] vc_do_resize+0x3ff/0x1340 drivers/tty/vt/vt.c:1229 fbcon_modechanged+0x36e/0x790 drivers/video/fbdev/core/fbcon.c:2989 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3047 fb_set_var+0xad0/0xd40 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x390/0x6e0 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 11862: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] kasan_set_free_info mm/kasan/common.c:317 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 ext4_ext_map_blocks+0x8b7/0x3710 fs/ext4/extents.c:4319 ext4_map_blocks+0x4cb/0x1650 fs/ext4/inode.c:621 mpage_map_one_extent fs/ext4/inode.c:2364 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2417 [inline] ext4_writepages+0x19a8/0x31d0 fs/ext4/inode.c:2770 do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 __filemap_fdatawrite_range+0x2aa/0x390 mm/filemap.c:421 file_write_and_wait_range+0x172/0x200 mm/filemap.c:760 ext4_sync_file+0x46b/0x10d0 fs/ext4/fsync.c:153 vfs_fsync_range+0x138/0x220 fs/sync.c:197 generic_write_sync include/linux/fs.h:2872 [inline] ext4_buffered_write_iter+0x2fd/0x450 fs/ext4/file.c:277 ext4_file_write_iter+0x1ec/0x13f0 fs/ext4/file.c:642 call_write_iter include/linux/fs.h:1907 [inline] do_iter_readv_writev+0x5a8/0x850 fs/read_write.c:694 do_iter_write fs/read_write.c:999 [inline] do_iter_write+0x18b/0x600 fs/read_write.c:980 vfs_iter_write+0x70/0xa0 fs/read_write.c:1040 iter_file_splice_write+0x684/0xb00 fs/splice.c:760 do_splice_from fs/splice.c:863 [inline] direct_splice_actor+0x115/0x160 fs/splice.c:1037 splice_direct_to_actor+0x38c/0x980 fs/splice.c:992 do_splice_direct+0x1b4/0x280 fs/splice.c:1080 do_sendfile+0x555/0xc50 fs/read_write.c:1521 __do_sys_sendfile64 fs/read_write.c:1582 [inline] __se_sys_sendfile64 fs/read_write.c:1568 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1568 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 The buggy address belongs to the object at ffff8880a6662700 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 12 bytes to the right of 96-byte region [ffff8880a6662700, ffff8880a6662760) The buggy address belongs to the page: page:ffffea0002999880 refcount:1 mapcount:0 mapping:000000009c4ce0d8 index:0xffff8880a6662f00 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002553e88 ffffea00025ae048 ffff8880aa000540 raw: ffff8880a6662f00 ffff8880a6662000 000000010000000e 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a6662600: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880a6662680: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff8880a6662700: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ^ ffff8880a6662780: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880a6662800: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================