================================================================== BUG: KASAN: slab-out-of-bounds in soft_cursor+0x458/0xa10 drivers/video/fbdev/core/softcursor.c:70 Read of size 32 at addr ffff888027648c00 by task syz.1.930/8188 CPU: 1 UID: 0 PID: 8188 Comm: syz.1.930 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:186 [inline] kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200 __asan_memcpy+0x23/0x60 mm/kasan/shadow.c:105 soft_cursor+0x458/0xa10 drivers/video/fbdev/core/softcursor.c:70 ccw_cursor+0xd7f/0x15b0 drivers/video/fbdev/core/fbcon_ccw.c:341 fbcon_cursor+0x43c/0x5e0 drivers/video/fbdev/core/fbcon.c:1427 hide_cursor+0x87/0x230 drivers/tty/vt/vt.c:883 redraw_screen+0x5d4/0x760 drivers/tty/vt/vt.c:985 vc_do_resize+0xc3d/0xeb0 drivers/tty/vt/vt.c:1309 vc_resize include/linux/vt_kern.h:49 [inline] fbcon_do_set_font+0x443/0x8c0 drivers/video/fbdev/core/fbcon.c:2435 fbcon_set_font+0x4be/0x730 drivers/video/fbdev/core/fbcon.c:2518 con_font_set drivers/tty/vt/vt.c:4992 [inline] con_font_op+0x9c0/0x1040 drivers/tty/vt/vt.c:5032 compat_kdfontop_ioctl drivers/tty/vt/vt_ioctl.c:1021 [inline] vt_compat_ioctl+0x228/0x4e0 drivers/tty/vt/vt_ioctl.c:1080 tty_compat_ioctl+0x1b4/0x420 drivers/tty/tty_io.c:2971 __do_compat_sys_ioctl fs/ioctl.c:695 [inline] __se_compat_sys_ioctl fs/ioctl.c:638 [inline] __ia32_compat_sys_ioctl+0x2cf/0x360 fs/ioctl.c:638 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7ff2fec Code: Unable to access opcode bytes at 0xf7ff2fc2. RSP: 002b:00000000f54b650c EFLAGS: 00000292 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000004b72 RDX: 0000000080000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 8050: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5334 [inline] __kmalloc_noprof+0x322/0x820 mm/slub.c:5359 _kmalloc_noprof include/linux/slab.h:992 [inline] _kmalloc_array_noprof include/linux/slab.h:1208 [inline] font_data_rotate+0x353/0x3b0 lib/fonts/font_rotate.c:231 fbcon_rotate_font+0x2bf/0x510 drivers/video/fbdev/core/fbcon_rotate.c:33 fbcon_modechanged+0x218/0x7f0 drivers/video/fbdev/core/fbcon.c:2664 fbcon_set_all_vcs+0x39b/0x470 drivers/video/fbdev/core/fbcon.c:2725 fbcon_rotate_all drivers/video/fbdev/core/fbcon.c:254 [inline] rotate_all_store+0x31e/0x410 drivers/video/fbdev/core/fbcon.c:3218 dev_attr_store+0x58/0x80 drivers/base/core.c:2505 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff888027648800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes to the right of allocated 1024-byte region [ffff888027648800, ffff888027648c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88802764f800 pfn:0x27648 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801bc42dc0 ffffea0000abe010 ffffea0000a9c410 raw: ffff88802764f800 0000000800100006 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801bc42dc0 ffffea0000abe010 ffffea0000a9c410 head: ffff88802764f800 0000000800100006 00000000f5000000 0000000000000000 head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1155, tgid 1155 (kworker/u33:7), ts 52962374570, free_ts 52643445164 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3266 [inline] allocate_slab mm/slub.c:3380 [inline] new_slab+0xa2/0x640 mm/slub.c:3426 refill_objects+0xe3/0x410 mm/slub.c:7310 refill_sheaf mm/slub.c:2804 [inline] __pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675 alloc_from_pcs mm/slub.c:4773 [inline] slab_alloc_node mm/slub.c:4905 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kmalloc_noprof+0x66d/0x820 mm/slub.c:5359 _kmalloc_noprof include/linux/slab.h:992 [inline] _kzalloc_noprof include/linux/slab.h:1309 [inline] ieee802_11_parse_elems_full+0x17c/0x3bc0 net/mac80211/parse.c:1073 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2551 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1540 [inline] ieee80211_ibss_rx_queued_mgmt+0xc96/0x1c70 net/mac80211/ibss.c:1571 ieee80211_iface_process_skb net/mac80211/iface.c:1769 [inline] ieee80211_iface_work+0xa9a/0x1070 net/mac80211/iface.c:1823 cfg80211_wiphy_work+0x2b7/0x550 net/wireless/core.c:538 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 page last free pid 5906 tgid 5905 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] kmem_cache_alloc_node_noprof+0x27d/0x6b0 mm/slub.c:4989 __alloc_skb+0x140/0x710 net/core/skbuff.c:704 alloc_skb include/linux/skbuff.h:1384 [inline] alloc_skb_with_frags+0xdd/0x760 net/core/skbuff.c:6775 sock_alloc_send_pskb+0x801/0x980 net/core/sock.c:3012 unix_dgram_sendmsg+0x3c7/0x1810 net/unix/af_unix.c:2137 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2738 __sys_sendmmsg+0x309/0x440 net/socket.c:2820 __compat_sys_sendmmsg net/compat.c:359 [inline] __do_compat_sys_sendmmsg net/compat.c:366 [inline] __se_compat_sys_sendmmsg net/compat.c:363 [inline] __ia32_compat_sys_sendmmsg+0x9d/0x100 net/compat.c:363 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Memory state around the buggy address: ffff888027648b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888027648b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888027648c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888027648c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888027648d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================