================================================================== BUG: KASAN: use-after-free in batadv_interface_tx+0xa45/0x14a0 net/batman-adv/soft-interface.c:227 Read of size 2 at addr ffff888098a2c7cb by task syz-executor3/6626 CPU: 0 PID: 6626 Comm: syz-executor3 Not tainted 5.0.0-rc4+ #44 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/generic_report.c:145 batadv_interface_tx+0xa45/0x14a0 net/batman-adv/soft-interface.c:227 __netdev_start_xmit include/linux/netdevice.h:4385 [inline] netdev_start_xmit include/linux/netdevice.h:4394 [inline] dev_direct_xmit+0x346/0x640 net/core/dev.c:3930 packet_direct_xmit+0xfb/0x170 net/packet/af_packet.c:246 packet_snd net/packet/af_packet.c:2933 [inline] packet_sendmsg+0x3879/0x5ab0 net/packet/af_packet.c:2958 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 __sys_sendto+0x262/0x380 net/socket.c:1810 __do_sys_sendto net/socket.c:1822 [inline] __se_sys_sendto net/socket.c:1818 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1818 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e39 Code: ad b8 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f73c6135c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000457e39 RDX: 000000000000004c RSI: 0000000020000180 RDI: 0000000000000006 RBP: 000000000073c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f73c61366d4 R13: 00000000004c548a R14: 00000000004d9260 R15: 00000000ffffffff Allocated by task 5167: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc mm/kasan/common.c:504 [inline] kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:411 kmem_cache_alloc+0x12d/0x710 mm/slab.c:3543 vm_area_alloc+0x20/0x110 kernel/fork.c:333 do_brk_flags+0x634/0x9f0 mm/mmap.c:3030 vm_brk_flags+0x176/0x250 mm/mmap.c:3070 load_elf_interp fs/binfmt_elf.c:654 [inline] load_elf_binary+0x383c/0x53f0 fs/binfmt_elf.c:1087 search_binary_handler fs/exec.c:1656 [inline] search_binary_handler+0x17f/0x570 fs/exec.c:1634 exec_binprm fs/exec.c:1698 [inline] __do_execve_file.isra.0+0x1394/0x23f0 fs/exec.c:1818 do_execveat_common fs/exec.c:1865 [inline] do_execve+0x33/0x40 fs/exec.c:1882 call_usermodehelper_exec_async+0x5b5/0x740 kernel/umh.c:111 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Freed by task 5167: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3749 vm_area_free+0x1d/0x30 kernel/fork.c:352 remove_vma+0x142/0x180 mm/mmap.c:185 exit_mmap+0x369/0x530 mm/mmap.c:3151 __mmput kernel/fork.c:1047 [inline] mmput+0x15f/0x4c0 kernel/fork.c:1068 exit_mm kernel/exit.c:545 [inline] do_exit+0x838/0x2db0 kernel/exit.c:854 do_group_exit+0x135/0x370 kernel/exit.c:971 __do_sys_exit_group kernel/exit.c:982 [inline] __se_sys_exit_group kernel/exit.c:980 [inline] __x64_sys_exit_group+0x44/0x50 kernel/exit.c:980 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888098a2c738 which belongs to the cache vm_area_struct of size 200 The buggy address is located 147 bytes inside of 200-byte region [ffff888098a2c738, ffff888098a2c800) The buggy address belongs to the page: page:ffffea0002628b00 count:1 mapcount:0 mapping:ffff8880aa53d480 index:0xffff888098a2c948 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0002360688 ffffea00025a2408 ffff8880aa53d480 raw: ffff888098a2c948 ffff888098a2c000 0000000100000005 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888098a2c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc ffff888098a2c700: fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb fb >ffff888098a2c780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888098a2c800: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff888098a2c880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================