================================================================== BUG: KASAN: slab-out-of-bounds in ipv6_gso_pull_exthdrs+0x57a/0x5f0 net/ipv6/ip6_offload.c:45 Read of size 1 at addr ffff8801acd84da9 by task syz-executor3/24212 CPU: 1 PID: 24212 Comm: syz-executor3 Not tainted 4.18.0-rc2+ #123 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+0x1c9/0x2b4 lib/dump_stack.c:113 FAT-fs (loop0): Directory bread(block 2563) failed print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 ipv6_gso_pull_exthdrs+0x57a/0x5f0 net/ipv6/ip6_offload.c:45 ipv6_gso_segment+0x37a/0x11e0 net/ipv6/ip6_offload.c:87 FAT-fs (loop0): Directory bread(block 2564) failed skb_mac_gso_segment+0x3b5/0x740 net/core/dev.c:2792 FAT-fs (loop0): Directory bread(block 2565) failed nsh_gso_segment+0x470/0xb40 net/nsh/nsh.c:111 skb_mac_gso_segment+0x3b5/0x740 net/core/dev.c:2792 FAT-fs (loop0): Directory bread(block 2566) failed FAT-fs (loop0): Directory bread(block 2567) failed __skb_gso_segment+0x3c3/0x880 net/core/dev.c:2865 skb_gso_segment include/linux/netdevice.h:4079 [inline] validate_xmit_skb+0x640/0xf30 net/core/dev.c:3104 FAT-fs (loop0): Directory bread(block 2568) failed __dev_queue_xmit+0xc14/0x3910 net/core/dev.c:3561 FAT-fs (loop0): Directory bread(block 2569) failed FAT-fs (loop0): Directory bread(block 2570) failed FAT-fs (loop0): Directory bread(block 2571) failed dev_queue_xmit+0x17/0x20 net/core/dev.c:3602 packet_snd net/packet/af_packet.c:2919 [inline] packet_sendmsg+0x428e/0x6130 net/packet/af_packet.c:2944 FAT-fs (loop0): Directory bread(block 2572) failed sock_sendmsg_nosec net/socket.c:641 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:651 __sys_sendto+0x3d7/0x670 net/socket.c:1797 __do_sys_sendto net/socket.c:1809 [inline] __se_sys_sendto net/socket.c:1805 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1805 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 syz-executor1 (24180) used greatest stack depth: 12200 bytes left entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455a99 Code: 1d ba 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 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f164ead8c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f164ead96d4 RCX: 0000000000455a99 RDX: 0000000000000012 RSI: 0000000020000000 RDI: 0000000000000014 RBP: 000000000072bf48 R08: 00000000200000c0 R09: 000000000000001c R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004c0efd R14: 00000000004d0e00 R15: 0000000000000001 Allocated by task 19072: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554 ptlock_alloc+0x20/0x80 mm/memory.c:4721 ptlock_init include/linux/mm.h:1858 [inline] pgtable_page_ctor include/linux/mm.h:1892 [inline] pte_alloc_one+0x6b/0x1a0 arch/x86/mm/pgtable.c:38 __pte_alloc+0x2a/0x3c0 mm/memory.c:654 copy_pte_range mm/memory.c:1072 [inline] copy_pmd_range mm/memory.c:1148 [inline] copy_pud_range mm/memory.c:1182 [inline] copy_p4d_range mm/memory.c:1204 [inline] copy_page_range+0x1670/0x24d0 mm/memory.c:1266 dup_mmap kernel/fork.c:520 [inline] dup_mm kernel/fork.c:1243 [inline] copy_mm kernel/fork.c:1297 [inline] copy_process.part.39+0x4e69/0x7220 kernel/fork.c:1803 copy_process kernel/fork.c:1616 [inline] _do_fork+0x291/0x12a0 kernel/fork.c:2099 __do_sys_clone kernel/fork.c:2206 [inline] __se_sys_clone kernel/fork.c:2200 [inline] __x64_sys_clone+0xbf/0x150 kernel/fork.c:2200 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 19368: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x2d0 mm/slab.c:3756 ptlock_free+0x38/0x42 mm/memory.c:4730 pte_lock_deinit include/linux/mm.h:1868 [inline] pgtable_page_dtor include/linux/mm.h:1901 [inline] ___pte_free_tlb+0x45/0x140 arch/x86/mm/pgtable.c:64 __pte_free_tlb arch/x86/include/asm/pgalloc.h:73 [inline] free_pte_range mm/memory.c:446 [inline] free_pmd_range mm/memory.c:464 [inline] free_pud_range mm/memory.c:498 [inline] free_p4d_range mm/memory.c:532 [inline] free_pgd_range+0xc1d/0xf30 mm/memory.c:612 free_pgtables+0x2c3/0x380 mm/memory.c:644 exit_mmap+0x2d1/0x5b0 mm/mmap.c:3106 __mmput kernel/fork.c:970 [inline] mmput+0x265/0x620 kernel/fork.c:991 exec_mmap fs/exec.c:1044 [inline] flush_old_exec+0xbaf/0x2100 fs/exec.c:1276 load_elf_binary+0xa33/0x5610 fs/binfmt_elf.c:869 search_binary_handler+0x17d/0x570 fs/exec.c:1653 exec_binprm fs/exec.c:1695 [inline] __do_execve_file.isra.35+0x171d/0x2730 fs/exec.c:1819 do_execveat_common fs/exec.c:1866 [inline] do_execve fs/exec.c:1883 [inline] __do_sys_execve fs/exec.c:1964 [inline] __se_sys_execve fs/exec.c:1959 [inline] __x64_sys_execve+0x8f/0xc0 fs/exec.c:1959 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801acd84d68 which belongs to the cache page->ptl of size 56 The buggy address is located 9 bytes to the right of 56-byte region [ffff8801acd84d68, ffff8801acd84da0) The buggy address belongs to the page: page:ffffea0006b36100 count:1 mapcount:0 mapping:ffff8801da810040 index:0xffff8801acd84bb0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea0006cfccc8 ffffea0006bfb008 ffff8801da810040 raw: ffff8801acd84bb0 ffff8801acd84000 0000000100000020 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801acd84c80: fb fb fb fc fc fc fc fb fb fb fb fb fb fb fc fc ffff8801acd84d00: fc fc fb fb fb fb fb fb fb fc fc fc fc fb fb fb >ffff8801acd84d80: fb fb fb fb fc fc fc fc 00 00 00 00 00 00 00 fc ^ ffff8801acd84e00: fc fc fc fb fb fb fb fb fb fb fc fc fc fc fb fb ffff8801acd84e80: fb fb fb fb fb fc fc fc fc fb fb fb fb fb fb fb ==================================================================