================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:663 [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+0xa8a/0xc00 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff8880a9184b88 by task syz-executor.4/3979 CPU: 0 PID: 3979 Comm: syz-executor.4 Not tainted 4.14.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1dc mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold+0xa9/0x2b9 mm/kasan/report.c:393 __fb_pad_aligned_buffer include/linux/fb.h:663 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0xa8a/0xc00 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x3bb/0x480 drivers/video/fbdev/core/fbcon.c:1301 do_update_region+0x34b/0x5b0 drivers/tty/vt/vt.c:373 redraw_screen+0x562/0x760 drivers/tty/vt/vt.c:705 vc_do_resize+0xbe0/0xde0 drivers/tty/vt/vt.c:967 vt_ioctl+0x1a64/0x1f20 drivers/tty/vt/vt_ioctl.c:901 tty_ioctl+0x6c9/0x1220 drivers/tty/tty_io.c:2661 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45cb19 RSP: 002b:00007f3ec7422c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004f3580 RCX: 000000000045cb19 RDX: 0000000020001040 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000067e R14: 00000000004c9852 R15: 00007f3ec74236d4 Allocated by task 7348: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x14d/0x3f0 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] alloc_perf_context+0x44/0xe0 kernel/events/core.c:3859 find_get_context.isra.0+0x109/0x520 kernel/events/core.c:3948 SYSC_perf_event_open kernel/events/core.c:10173 [inline] SyS_perf_event_open+0x974/0x24b0 kernel/events/core.c:10004 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 6572: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xaf/0x190 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xcb/0x260 mm/slab.c:3815 skb_free_head+0x83/0xa0 net/core/skbuff.c:554 skb_release_data+0x57e/0x7d0 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+0xa7/0x330 net/core/skbuff.c:705 skb_free_datagram+0x16/0xe0 net/core/datagram.c:331 netlink_recvmsg+0x5ef/0xda0 net/netlink/af_netlink.c:1957 sock_recvmsg_nosec net/socket.c:819 [inline] sock_recvmsg net/socket.c:826 [inline] sock_recvmsg+0xc0/0x100 net/socket.c:822 ___sys_recvmsg+0x21f/0x4d0 net/socket.c:2221 __sys_recvmsg+0xa0/0x120 net/socket.c:2266 SYSC_recvmsg net/socket.c:2278 [inline] SyS_recvmsg+0x27/0x40 net/socket.c:2273 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff8880a9184a00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 392 bytes inside of 512-byte region [ffff8880a9184a00, ffff8880a9184c00) The buggy address belongs to the page: page:ffffea0002a46100 count:1 mapcount:0 mapping:ffff8880a9184000 index:0xffff8880a9184000 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffff8880a9184000 ffff8880a9184000 0000000100000005 raw: ffffea00023d9660 ffffea0002815360 ffff8880aa800940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a9184a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a9184b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc >ffff8880a9184b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880a9184c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a9184c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================