================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:674 [inline] BUG: KASAN: slab-out-of-bounds in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] BUG: KASAN: slab-out-of-bounds in bit_putcs+0xc74/0xe10 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff8880a4ed4e7f by task syz-executor347/6440 CPU: 0 PID: 6440 Comm: syz-executor347 Not tainted 4.19.115-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.cold+0x7c/0x212 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x88/0x2b9 mm/kasan/report.c:396 __fb_pad_aligned_buffer include/linux/fb.h:674 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0xc74/0xe10 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x434/0x4f0 drivers/video/fbdev/core/fbcon.c:1323 do_update_region+0x398/0x630 drivers/tty/vt/vt.c:677 redraw_screen+0x5e1/0x870 drivers/tty/vt/vt.c:1025 vc_do_resize+0x108e/0x1380 drivers/tty/vt/vt.c:1311 vt_ioctl+0x1fa2/0x2500 drivers/tty/vt/vt_ioctl.c:901 tty_ioctl+0x7a1/0x1420 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x440219 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 5b 14 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffecf702ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440219 RDX: 0000000020000040 RSI: 000000000000560a RDI: 0000000000000004 RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401b00 R13: 0000000000401b90 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6440: set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531 __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15b/0x770 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] fbcon_set_font+0x331/0x870 drivers/video/fbdev/core/fbcon.c:2644 con_font_set drivers/tty/vt/vt.c:4523 [inline] con_font_op+0xd3e/0x1130 drivers/tty/vt/vt.c:4588 vt_ioctl+0xcd0/0x2500 drivers/tty/vt/vt_ioctl.c:928 tty_ioctl+0x7a1/0x1420 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 4688: set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/kasan.c:521 __cache_free mm/slab.c:3503 [inline] kfree+0xce/0x220 mm/slab.c:3822 skb_free_head+0x91/0xb0 net/core/skbuff.c:554 skb_release_data+0x600/0x8c0 net/core/skbuff.c:574 skb_release_all+0x46/0x60 net/core/skbuff.c:631 __kfree_skb net/core/skbuff.c:645 [inline] consume_skb net/core/skbuff.c:705 [inline] consume_skb+0xda/0x380 net/core/skbuff.c:699 skb_free_datagram+0x16/0xf0 net/core/datagram.c:329 netlink_recvmsg+0x667/0xea0 net/netlink/af_netlink.c:1988 sock_recvmsg_nosec net/socket.c:795 [inline] sock_recvmsg net/socket.c:802 [inline] sock_recvmsg+0xca/0x110 net/socket.c:798 ___sys_recvmsg+0x271/0x580 net/socket.c:2277 __sys_recvmsg+0xe9/0x1b0 net/socket.c:2326 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a4ed4d40 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 319 bytes inside of 512-byte region [ffff8880a4ed4d40, ffff8880a4ed4f40) The buggy address belongs to the page: page:ffffea000293b500 count:1 mapcount:0 mapping:ffff88812c3dc940 index:0xffff8880a4ed40c0 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffffea0002969d88 ffffea00027d1508 ffff88812c3dc940 raw: ffff8880a4ed40c0 ffff8880a4ed40c0 0000000100000005 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a4ed4d00: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ffff8880a4ed4d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880a4ed4e00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ^ ffff8880a4ed4e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a4ed4f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================