On Mon, Jan 22, 2018 at 2:45 PM, David Ahern <dsah...@gmail.com> wrote: > [ cc William Tu ] > > On 1/22/18 12:58 PM, syzbot wrote: >> Hello, >> >> syzbot hit the following crash on net-next commit >> 9d6474e458b13a94a0d5b141f2b8f38adf1991ae (Mon Jan 22 02:55:38 2018 +0000) >> tun: add missing rcu annotation >> >> So far this crash happened 5 times on net-next. >> C reproducer is attached. >> syzkaller reproducer is attached. >> Raw console output is attached. >> compiler: gcc (GCC) 7.1.1 20170620 >> .config is attached. >> >> IMPORTANT: if you fix the bug, please add the following tag to the commit: >> Reported-by: syzbot+9723f2d288e49b492...@syzkaller.appspotmail.com >> It will help syzbot understand when the bug is fixed. See footer for >> details. >> If you forward the report, please keep this part and the footer. >> >> ================================================================== >> BUG: KASAN: slab-out-of-bounds in erspan_xmit+0x22d4/0x2430 >> net/ipv4/ip_gre.c:735 >> Read of size 2 at addr ffff8801c50bb08b by task syzkaller525754/3647 >> >> CPU: 0 PID: 3647 Comm: syzkaller525754 Not tainted 4.15.0-rc8+ #203 >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS >> Google 01/01/2011 >> Call Trace: >> __dump_stack lib/dump_stack.c:17 [inline] >> dump_stack+0x194/0x257 lib/dump_stack.c:53 >> print_address_description+0x73/0x250 mm/kasan/report.c:252 >> kasan_report_error mm/kasan/report.c:351 [inline] >> kasan_report+0x25b/0x340 mm/kasan/report.c:409 >> __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:440 >> erspan_xmit+0x22d4/0x2430 net/ipv4/ip_gre.c:735 >> __netdev_start_xmit include/linux/netdevice.h:4053 [inline] >> netdev_start_xmit include/linux/netdevice.h:4062 [inline] >> packet_direct_xmit+0x3ad/0x790 net/packet/af_packet.c:267 >> packet_snd net/packet/af_packet.c:2944 [inline] >> packet_sendmsg+0x3aed/0x60b0 net/packet/af_packet.c:2969 >> sock_sendmsg_nosec net/socket.c:630 [inline] >> sock_sendmsg+0xca/0x110 net/socket.c:640 >> SYSC_sendto+0x361/0x5c0 net/socket.c:1721 >> SyS_sendto+0x40/0x50 net/socket.c:1689 >> entry_SYSCALL_64_fastpath+0x29/0xa0 >> RIP: 0033:0x445649 >> RSP: 002b:00007ffe82dde5b8 EFLAGS: 00000217 ORIG_RAX: 000000000000002c >> RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000445649 >> RDX: 0000000000000000 RSI: 0000000020003fd9 RDI: 0000000000000004 >> RBP: 00000000004a78c5 R08: 0000000020008000 R09: 000000000000001c >> R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000402720 >> R13: 00000000004027b0 R14: 0000000000000000 R15: 0000000000000000 >> >> Allocated by task 3221: >> save_stack+0x43/0xd0 mm/kasan/kasan.c:447 >> set_track mm/kasan/kasan.c:459 [inline] >> kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 >> kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 >> kmem_cache_alloc+0x12e/0x760 mm/slab.c:3544 >> getname_flags+0xcb/0x580 fs/namei.c:138 >> getname+0x19/0x20 fs/namei.c:209 >> do_sys_open+0x2e7/0x6d0 fs/open.c:1053 >> SYSC_open fs/open.c:1077 [inline] >> SyS_open+0x2d/0x40 fs/open.c:1072 >> entry_SYSCALL_64_fastpath+0x29/0xa0 >> >> Freed by task 3221: >> save_stack+0x43/0xd0 mm/kasan/kasan.c:447 >> set_track mm/kasan/kasan.c:459 [inline] >> kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 >> __cache_free mm/slab.c:3488 [inline] >> kmem_cache_free+0x83/0x2a0 mm/slab.c:3746 >> putname+0xee/0x130 fs/namei.c:258 >> do_sys_open+0x31b/0x6d0 fs/open.c:1068 >> SYSC_open fs/open.c:1077 [inline] >> SyS_open+0x2d/0x40 fs/open.c:1072 >> entry_SYSCALL_64_fastpath+0x29/0xa0 >> >> The buggy address belongs to the object at ffff8801c50ba000 >> which belongs to the cache names_cache of size 4096 >> The buggy address is located 139 bytes to the right of >> 4096-byte region [ffff8801c50ba000, ffff8801c50bb000) >> The buggy address belongs to the page: >> page:ffffea0007142e80 count:1 mapcount:0 mapping:ffff8801c50ba000 >> index:0x0 compound_mapcount: 0 >> flags: 0x2fffc0000008100(slab|head) >> raw: 02fffc0000008100 ffff8801c50ba000 0000000000000000 0000000100000001 >> raw: ffffea0007145320 ffffea00071433a0 ffff8801dae2c600 0000000000000000 >> page dumped because: kasan: bad access detected >> >> Memory state around the buggy address: >> ffff8801c50baf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ffff8801c50bb000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >>> ffff8801c50bb080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >> ^ >> ffff8801c50bb100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >> ffff8801c50bb180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >> ================================================================== >> >> >> --- >> This bug is generated by a dumb bot. It may contain errors. >> See https://goo.gl/tpsmEJ for details. >> Direct all questions to syzkal...@googlegroups.com. >> >> syzbot will keep track of this bug report. >> If you forgot to add the Reported-by tag, once the fix for this bug is >> merged >> into any tree, please reply to this email with: >> #syz fix: exact-commit-title >> If you want to test a patch for this bug, please reply with: >> #syz test: git://repo/address.git branch >> and provide the patch inline or as an attachment. >> To mark this as a duplicate of another syzbot report, please reply with: >> #syz dup: exact-subject-of-another-report >> If it's a one-off invalid bug report, please reply with: >> #syz invalid >> Note: if the crash happens again, it will cause creation of a new bug >> report. >> Note: all commands must start from beginning of the line in the email body. >
Thanks. I'm working on it.
