================================================================== 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+0xbaf/0xd10 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff88809ab51e3f by task syz-executor.0/23484 CPU: 1 PID: 23484 Comm: syz-executor.0 Not tainted 4.19.164-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+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load1_noabort+0x88/0x90 mm/kasan/report.c:430 __fb_pad_aligned_buffer include/linux/fb.h:674 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0xbaf/0xd10 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x336/0x4f0 drivers/video/fbdev/core/fbcon.c:1269 do_update_region+0x399/0x630 drivers/tty/vt/vt.c:683 redraw_screen+0x5e1/0x870 drivers/tty/vt/vt.c:1031 fbcon_modechanged+0x6df/0x930 drivers/video/fbdev/core/fbcon.c:2685 fbcon_set_all_vcs+0x4d9/0x620 drivers/video/fbdev/core/fbcon.c:2721 fbcon_event_notify+0x1025/0x1d80 drivers/video/fbdev/core/fbcon.c:3061 notifier_call_chain+0xc0/0x230 kernel/notifier.c:93 __blocking_notifier_call_chain kernel/notifier.c:317 [inline] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] blocking_notifier_call_chain kernel/notifier.c:328 [inline] blocking_notifier_call_chain+0x85/0xa0 kernel/notifier.c:325 fb_set_var+0xc51/0xe20 drivers/video/fbdev/core/fbmem.c:1042 do_fb_ioctl+0x3cf/0xb50 drivers/video/fbdev/core/fbmem.c:1115 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1230 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/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: 0033:0x45e219 Code: 0d b4 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 b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fad16de4c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e219 RDX: 0000000020000100 RSI: 0000000000004601 RDI: 0000000000000006 RBP: 000000000119bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffe530aca4f R14: 00007fad16de59c0 R15: 000000000119bf8c Allocated by task 16594: __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15a/0x3c0 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] fbcon_set_font+0x34f/0x8a0 drivers/video/fbdev/core/fbcon.c:2479 con_font_set drivers/tty/vt/vt.c:4537 [inline] con_font_op+0x92e/0xef0 drivers/tty/vt/vt.c:4581 vt_ioctl+0x116b/0x2380 drivers/tty/vt/vt_ioctl.c:938 tty_ioctl+0x5b0/0x15c0 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/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 15789: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 skb_free_head net/core/skbuff.c:554 [inline] skb_release_data+0x6de/0x920 net/core/skbuff.c:574 skb_release_all net/core/skbuff.c:631 [inline] __kfree_skb net/core/skbuff.c:645 [inline] kfree_skb+0x11a/0x3d0 net/core/skbuff.c:663 sctp_ulpq_tail_event+0x781/0xc00 net/sctp/ulpqueue.c:286 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1472 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0xd2b/0x5110 net/sctp/sm_sideeffect.c:1170 sctp_assoc_bh_rcv+0x345/0x650 net/sctp/associola.c:1073 sctp_inq_push+0x1da/0x270 net/sctp/inqueue.c:95 sctp_backlog_rcv+0x1e9/0x11e0 net/sctp/input.c:356 sk_backlog_rcv include/net/sock.h:950 [inline] __release_sock+0x134/0x3a0 net/core/sock.c:2344 release_sock+0x54/0x1b0 net/core/sock.c:2881 sctp_connect net/sctp/socket.c:4525 [inline] sctp_inet_connect+0x16e/0x200 net/sctp/socket.c:4538 __sys_connect+0x265/0x2c0 net/socket.c:1663 __do_sys_connect net/socket.c:1674 [inline] __se_sys_connect net/socket.c:1671 [inline] __x64_sys_connect+0x6f/0xb0 net/socket.c:1671 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 ffff88809ab51d00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 319 bytes inside of 512-byte region [ffff88809ab51d00, ffff88809ab51f00) The buggy address belongs to the page: page:ffffea00026ad440 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffffea00026d4148 ffffea0002a83908 ffff88813bff0940 raw: 0000000000000000 ffff88809ab51080 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809ab51d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88809ab51d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88809ab51e00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88809ab51e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809ab51f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================