================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:654 [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+0x103a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff8880932a5bb2 by task syz-executor.0/14324 CPU: 0 PID: 14324 Comm: syz-executor.0 Not tainted 5.9.0-rc7-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+0x1d6/0x29e lib/dump_stack.c:118 print_address_description+0x66/0x620 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report+0x132/0x1d0 mm/kasan/report.c:530 __fb_pad_aligned_buffer include/linux/fb.h:654 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0x103a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x790/0xaf0 drivers/video/fbdev/core/fbcon.c:1308 con_flush drivers/tty/vt/vt.c:2575 [inline] do_con_write+0x2853/0xd580 drivers/tty/vt/vt.c:2905 con_write+0x20/0x40 drivers/tty/vt/vt.c:3250 process_output_block drivers/tty/n_tty.c:595 [inline] n_tty_write+0xcbf/0x1170 drivers/tty/n_tty.c:2333 do_tty_write drivers/tty/tty_io.c:962 [inline] tty_write+0x593/0x940 drivers/tty/tty_io.c:1046 vfs_write+0x2d3/0xd10 fs/read_write.c:584 ksys_write+0x11b/0x220 fs/read_write.c:639 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45de89 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:00007fd0be7bbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000003a600 RCX: 000000000045de89 RDX: 000000000000fd95 RSI: 0000000020001440 RDI: 0000000000000006 RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007ffdea595abf R14: 00007fd0be7bc9c0 R15: 000000000118bf2c Allocated by task 9670: kasan_save_stack mm/kasan/common.c:48 [inline] kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461 __do_kmalloc mm/slab.c:3659 [inline] __kmalloc+0x205/0x300 mm/slab.c:3668 kmalloc include/linux/slab.h:559 [inline] fbcon_set_font+0x2c4/0x970 drivers/video/fbdev/core/fbcon.c:2496 con_font_set drivers/tty/vt/vt.c:4663 [inline] con_font_op+0xebc/0x1630 drivers/tty/vt/vt.c:4728 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:506 [inline] vt_ioctl+0xd7f/0x3d70 drivers/tty/vt/vt_ioctl.c:856 tty_ioctl+0xee4/0x15c0 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Last call_rcu(): kasan_save_stack+0x27/0x50 mm/kasan/common.c:48 kasan_record_aux_stack+0x7b/0xb0 mm/kasan/generic.c:346 __call_rcu kernel/rcu/tree.c:2896 [inline] call_rcu+0x141/0x830 kernel/rcu/tree.c:2970 notify_and_destroy net/sched/sch_api.c:1005 [inline] qdisc_graft+0x4b9/0x1250 net/sched/sch_api.c:1112 tc_modify_qdisc+0xddd/0x1d90 net/sched/sch_api.c:1673 rtnetlink_rcv_msg+0x889/0xd40 net/core/rtnetlink.c:5563 netlink_rcv_skb+0x190/0x3a0 net/netlink/af_netlink.c:2470 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x786/0x940 net/netlink/af_netlink.c:1330 netlink_sendmsg+0xa57/0xd70 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg net/socket.c:671 [inline] ____sys_sendmsg+0x519/0x800 net/socket.c:2353 ___sys_sendmsg net/socket.c:2407 [inline] __sys_sendmsg+0x2b1/0x360 net/socket.c:2440 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8880932a5800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 946 bytes inside of 1024-byte region [ffff8880932a5800, ffff8880932a5c00) The buggy address belongs to the page: page:00000000f01313a0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x932a5 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002741448 ffffea00024dac48 ffff8880aa440700 raw: 0000000000000000 ffff8880932a5000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880932a5a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880932a5b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880932a5b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880932a5c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880932a5c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================