================================================================== 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 ffff8880917ab9ca by task syz-executor.1/28486 CPU: 1 PID: 28486 Comm: syz-executor.1 Not tainted 4.19.128-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 do_update_region+0x2cf/0x630 drivers/tty/vt/vt.c:673 redraw_screen+0x5e1/0x870 drivers/tty/vt/vt.c:1031 vc_do_resize+0x108e/0x1380 drivers/tty/vt/vt.c:1317 vt_ioctl+0x1fa2/0x2500 drivers/tty/vt/vt_ioctl.c:901 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 RIP: 0033:0x45ca59 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:00007f32a0a87c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004f3120 RCX: 000000000045ca59 RDX: 0000000020000000 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000067a R14: 00000000004c973d R15: 00007f32a0a886d4 Allocated by task 10182: __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 vt_ioctl+0xcd0/0x2500 drivers/tty/vt/vt_ioctl.c:928 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 6459: __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+0x11/0x20 net/core/skbuff.c:645 sk_wmem_free_skb include/net/sock.h:1462 [inline] tcp_rtx_queue_unlink_and_free include/net/tcp.h:1764 [inline] tcp_clean_rtx_queue net/ipv4/tcp_input.c:3153 [inline] tcp_ack+0x1be6/0x4ba0 net/ipv4/tcp_input.c:3678 tcp_rcv_established+0x11fa/0x1c30 net/ipv4/tcp_input.c:5567 tcp_v4_do_rcv+0x605/0x8b0 net/ipv4/tcp_ipv4.c:1535 sk_backlog_rcv include/net/sock.h:946 [inline] __release_sock+0x134/0x3a0 net/core/sock.c:2342 release_sock+0x54/0x1c0 net/core/sock.c:2858 tcp_sendmsg+0x36/0x40 net/ipv4/tcp.c:1461 inet_sendmsg+0x12e/0x590 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:632 sock_write_iter+0x283/0x3c0 net/socket.c:901 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x512/0x760 fs/read_write.c:487 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 The buggy address belongs to the object at ffff8880917ab6c0 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 778 bytes inside of 1024-byte region [ffff8880917ab6c0, ffff8880917abac0) The buggy address belongs to the page: page:ffffea000245ea80 count:1 mapcount:0 mapping:ffff88812c3dcac0 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea0000d3c208 ffffea00029f5508 ffff88812c3dcac0 raw: 0000000000000000 ffff8880917aa040 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880917ab880: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ffff8880917ab900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880917ab980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880917aba00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880917aba80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================