IPVS: ftp: loaded support on port[0] = 21 ================================================================== 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+0xbaa/0xd10 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff8880a8143172 by task syz-executor.0/4689 CPU: 0 PID: 4689 Comm: syz-executor.0 Not tainted 4.19.126-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+0x1fc/0x2fe lib/dump_stack.c:118 print_address_description.cold+0x54/0x222 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+0xbaa/0xd10 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x424/0x4e0 drivers/video/fbdev/core/fbcon.c:1323 con_flush drivers/tty/vt/vt.c:2552 [inline] do_con_write.part.0+0xf37/0x1db0 drivers/tty/vt/vt.c:2802 do_con_write drivers/tty/vt/vt.c:2571 [inline] con_write+0x41/0xe0 drivers/tty/vt/vt.c:3138 process_output_block drivers/tty/n_tty.c:593 [inline] n_tty_write+0x3ee/0x1080 drivers/tty/n_tty.c:2331 do_tty_write drivers/tty/tty_io.c:960 [inline] tty_write+0x455/0x790 drivers/tty/tty_io.c:1044 __vfs_write+0xf7/0x760 fs/read_write.c:485 vfs_write+0x1f3/0x540 fs/read_write.c:549 ksys_write+0x12b/0x2a0 fs/read_write.c:599 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ca69 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:00007fcefdf63c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000050c680 RCX: 000000000045ca69 RDX: 0000000000001006 RSI: 0000000020001440 RDI: 0000000000000004 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000ce0 R14: 00000000004cf306 R15: 00007fcefdf646d4 Allocated by task 2342: __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15a/0x3c0 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:4529 [inline] con_font_op+0xd3e/0x1130 drivers/tty/vt/vt.c:4594 do_fontx_ioctl drivers/tty/vt/vt_ioctl.c:265 [inline] vt_ioctl+0x322/0x2500 drivers/tty/vt/vt_ioctl.c:945 tty_ioctl+0x7a5/0x1420 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 1649: __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+0x623/0x8e0 net/core/skbuff.c:574 skb_release_all+0x46/0x60 net/core/skbuff.c:631 __kfree_skb net/core/skbuff.c:645 [inline] kfree_skb+0xe1/0x390 net/core/skbuff.c:663 l2tp_xmit_skb+0xd14/0x13b0 net/l2tp/l2tp_core.c:1093 pppol2tp_sendmsg+0x479/0x660 net/l2tp/l2tp_ppp.c:329 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:632 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2115 __sys_sendmmsg+0x195/0x470 net/socket.c:2210 __do_sys_sendmmsg net/socket.c:2239 [inline] __se_sys_sendmmsg net/socket.c:2236 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2236 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 ffff8880a8142dc0 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 946 bytes inside of 1024-byte region [ffff8880a8142dc0, ffff8880a81431c0) The buggy address belongs to the page: page:ffffea0002a05080 count:1 mapcount:0 mapping:ffff88812c3dcac0 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea0002a0ab88 ffffea00029e4d08 ffff88812c3dcac0 raw: 0000000000000000 ffff8880a8142040 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a8143000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a8143080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a8143100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880a8143180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a8143200: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ================================================================== IPVS: ftp: loaded support on port[0] = 21