================================================================== BUG: KASAN: slab-out-of-bounds in fl6_update_dst+0x2bb/0x2c0 net/ipv6/exthdrs.c:1356 Read of size 16 at addr ffff8880a8d338c8 by task syz-executor.3/29230 CPU: 1 PID: 29230 Comm: syz-executor.3 Not tainted 5.7.0-rc5-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+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x413 mm/kasan/report.c:382 __kasan_report.cold+0x20/0x38 mm/kasan/report.c:511 kasan_report+0x33/0x50 mm/kasan/common.c:625 fl6_update_dst+0x2bb/0x2c0 net/ipv6/exthdrs.c:1356 rawv6_sendmsg+0xd7e/0x3900 net/ipv6/raw.c:912 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:810 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x32f/0x810 net/socket.c:2352 ___sys_sendmsg+0x100/0x170 net/socket.c:2406 __sys_sendmmsg+0x195/0x480 net/socket.c:2496 __do_sys_sendmmsg net/socket.c:2525 [inline] __se_sys_sendmmsg net/socket.c:2522 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2522 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 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:00007fdd4d209c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00000000004fc580 RCX: 000000000045ca29 RDX: 00000000000002e9 RSI: 0000000020000480 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008dd R14: 00000000004cba1f R15: 00007fdd4d20a6d4 Allocated by task 29230: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x161/0x7a0 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] sock_kmalloc net/core/sock.c:2174 [inline] sock_kmalloc+0xb5/0x100 net/core/sock.c:2165 ipv6_renew_options+0x274/0x940 net/ipv6/exthdrs.c:1275 do_ipv6_setsockopt.isra.0+0x2e75/0x41c0 net/ipv6/ipv6_sockglue.c:470 ipv6_setsockopt+0xfb/0x180 net/ipv6/ipv6_sockglue.c:956 rawv6_setsockopt+0x55/0x140 net/ipv6/raw.c:1081 __sys_setsockopt+0x248/0x480 net/socket.c:2127 __do_sys_setsockopt net/socket.c:2143 [inline] __se_sys_setsockopt net/socket.c:2140 [inline] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2140 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 28074: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] kasan_set_free_info mm/kasan/common.c:317 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456 __cache_free mm/slab.c:3426 [inline] kmem_cache_free_bulk+0x7d/0x280 mm/slab.c:3721 kfree_bulk include/linux/slab.h:412 [inline] kfree_rcu_work+0x1a1/0x480 kernel/rcu/tree.c:2859 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 The buggy address belongs to the object at ffff8880a8d33800 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 200 bytes inside of 256-byte region [ffff8880a8d33800, ffff8880a8d33900) The buggy address belongs to the page: page:ffffea0002a34cc0 refcount:1 mapcount:0 mapping:0000000097b5094f index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00027f0808 ffffea00016e7048 ffff8880aa0008c0 raw: 0000000000000000 ffff8880a8d33000 0000000100000008 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a8d33780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a8d33800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880a8d33880: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc ^ ffff8880a8d33900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a8d33980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================