================================================================== BUG: KASAN: slab-out-of-bounds in batadv_interface_tx+0x1194/0x1880 net/batman-adv/soft-interface.c:226 Read of size 2 at addr ffff88809fcd558b by task syz-executor2/1966 CPU: 0 PID: 1966 Comm: syz-executor2 Not tainted 4.20.0+ #7 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+0x1db/0x2d0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:443 batadv_interface_tx+0x1194/0x1880 net/batman-adv/soft-interface.c:226 __netdev_start_xmit include/linux/netdevice.h:4382 [inline] netdev_start_xmit include/linux/netdevice.h:4391 [inline] dev_direct_xmit+0x368/0x670 net/core/dev.c:3930 packet_direct_xmit+0xfb/0x170 net/packet/af_packet.c:246 packet_snd net/packet/af_packet.c:2932 [inline] packet_sendmsg+0x2753/0x6830 net/packet/af_packet.c:2957 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 __sys_sendto+0x387/0x5f0 net/socket.c:1788 __do_sys_sendto net/socket.c:1800 [inline] __se_sys_sendto net/socket.c:1796 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1796 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: 6d 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f7a4e483c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000457ec9 RDX: 000000000000000f RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7a4e4846d4 R13: 00000000004c5284 R14: 00000000004d8ba8 R15: 00000000ffffffff Allocated by task 1003: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531 __do_kmalloc_node mm/slab.c:3684 [inline] __kmalloc_node+0x51/0x80 mm/slab.c:3691 kmalloc_node include/linux/slab.h:589 [inline] kvmalloc_node+0x68/0x100 mm/util.c:416 kvmalloc include/linux/mm.h:577 [inline] seq_buf_alloc fs/seq_file.c:32 [inline] seq_read+0x832/0x1130 fs/seq_file.c:204 proc_reg_read+0x29a/0x3c0 fs/proc/inode.c:231 __vfs_read+0x116/0xa60 fs/read_write.c:416 vfs_read+0x194/0x3d0 fs/read_write.c:452 ksys_read+0x105/0x260 fs/read_write.c:578 __do_sys_read fs/read_write.c:588 [inline] __se_sys_read fs/read_write.c:586 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:586 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 1003: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3817 kvfree+0x61/0x70 mm/util.c:445 seq_release fs/seq_file.c:359 [inline] single_release+0x7e/0xc0 fs/seq_file.c:596 close_pdeo.part.0+0x12b/0x4a0 fs/proc/inode.c:176 close_pdeo+0x1c2/0x1f0 fs/proc/inode.c:186 proc_reg_release+0xcc/0x120 fs/proc/inode.c:395 __fput+0x3c5/0xaf0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x1f4/0x2b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x32a/0x3b0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x696/0x800 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88809fcd4300 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 651 bytes to the right of 4096-byte region [ffff88809fcd4300, ffff88809fcd5300) The buggy address belongs to the page: page:ffffea00027f3500 count:1 mapcount:0 mapping:ffff88812c3f0dc0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0001a7a408 ffffea0001a93188 ffff88812c3f0dc0 raw: 0000000000000000 ffff88809fcd4300 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809fcd5480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809fcd5500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88809fcd5580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88809fcd5600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809fcd5680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================