xt_ipcomp: unknown flags 3 ================================================================== BUG: KASAN: use-after-free in __fb_pad_aligned_buffer include/linux/fb.h:674 [inline] BUG: KASAN: use-after-free in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] BUG: KASAN: use-after-free in bit_putcs+0xbaf/0xd10 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff88808b96d5b0 by task syz-executor.1/28661 CPU: 0 PID: 28661 Comm: syz-executor.1 Not tainted 4.19.131-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:1323 con_flush drivers/tty/vt/vt.c:2552 [inline] do_con_write+0x1269/0x1d90 drivers/tty/vt/vt.c:2757 con_write+0x22/0xb0 drivers/tty/vt/vt.c:3138 process_output_block drivers/tty/n_tty.c:593 [inline] n_tty_write+0x3c0/0xff0 drivers/tty/n_tty.c:2331 do_tty_write drivers/tty/tty_io.c:960 [inline] tty_write+0x496/0x810 drivers/tty/tty_io.c:1044 __vfs_write+0xf7/0x770 fs/read_write.c:485 __kernel_write+0x109/0x370 fs/read_write.c:506 write_pipe_buf+0x153/0x1f0 fs/splice.c:798 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x389/0x800 fs/splice.c:627 splice_from_pipe fs/splice.c:662 [inline] default_file_splice_write+0xd8/0x180 fs/splice.c:810 do_splice_from fs/splice.c:852 [inline] direct_splice_actor+0x115/0x160 fs/splice.c:1025 splice_direct_to_actor+0x33f/0x8d0 fs/splice.c:980 do_splice_direct+0x1a7/0x270 fs/splice.c:1068 do_sendfile+0x550/0xc30 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45cb29 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:00007f9a99279c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000004fd6e0 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0800000080004103 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000902 R14: 00000000004cbe0a R15: 00007f9a9927a6d4 Allocated by task 26162: __do_kmalloc_node mm/slab.c:3689 [inline] __kmalloc_node_track_caller+0x4c/0x70 mm/slab.c:3703 __kmalloc_reserve net/core/skbuff.c:137 [inline] __alloc_skb+0xae/0x560 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:995 [inline] alloc_skb_with_frags+0x92/0x570 net/core/skbuff.c:5303 sock_alloc_send_pskb+0x6e1/0x830 net/core/sock.c:2090 unix_dgram_sendmsg+0x3a5/0x12c0 net/unix/af_unix.c:1701 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:632 sock_write_iter+0x287/0x3c0 net/socket.c:901 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x51b/0x770 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 Freed by task 3692: __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] consume_skb+0x113/0x3d0 net/core/skbuff.c:705 skb_free_datagram+0x16/0xf0 net/core/datagram.c:329 unix_dgram_recvmsg+0x73e/0xe80 net/unix/af_unix.c:2203 sock_recvmsg_nosec net/socket.c:795 [inline] sock_recvmsg net/socket.c:802 [inline] sock_recvmsg+0xca/0x110 net/socket.c:798 ___sys_recvmsg+0x255/0x570 net/socket.c:2277 __sys_recvmsg net/socket.c:2326 [inline] __do_sys_recvmsg net/socket.c:2336 [inline] __se_sys_recvmsg net/socket.c:2333 [inline] __x64_sys_recvmsg+0x12f/0x220 net/socket.c:2333 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 ffff88808b96d580 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 48 bytes inside of 512-byte region [ffff88808b96d580, ffff88808b96d780) The buggy address belongs to the page: page:ffffea00022e5b40 count:1 mapcount:0 mapping:ffff88812c39c940 index:0xffff88808b96d580 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffffea000281a788 ffffea00022be788 ffff88812c39c940 raw: ffff88808b96d580 ffff88808b96d080 0000000100000005 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808b96d480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88808b96d500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88808b96d580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808b96d600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808b96d680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================