On Fri, May 19, 2017 at 4:36 PM, 'Eric Dumazet' via syzkaller <syzkal...@googlegroups.com> wrote: > On Fri, May 19, 2017 at 5:57 AM, Andrey Konovalov <andreyk...@google.com> > wrote: >> On Fri, May 19, 2017 at 12:18 PM, <idaif...@gmail.com> wrote: >>> Hi, >>> >>> I've got the following bug report while fuzzing the >>> kernel(master-f83246089ca) with syzkaller. >>> >>> program and config are attached. >> >> Hi! >> >> Thanks for the report! >> >> Adding kernel maintainers. >> >> I can confirm that we've hist this bug multiple times, but never been >> able to reproduce it. >> >> I was able to reproduce it on 2ea659a9ef488125eb46da6eb571de5eae5c43f6 >> (4.12-rc1). >> >> Using the attached syzkaller program I was able to generate C >> reproducer, attached. Sometimes I need to run it a few times to >> trigger the bug. >> >> @idaifish If you find more bugs please run ./scripts/get_maintainer.pl >> to get the list of subsystem maintainers and add them to the >> recipients. I've updated instructions of how to report kernel bugs >> found with syzkaller in README. >> >> Thanks! >> >>> >>> ======================================================= >>> kasan: GPF could be caused by NULL-ptr deref or user memory access >>> general protection fault: 0000 [#1] SMP KASAN >>> Dumping ftrace buffer: >>> (ftrace buffer empty) >>> Modules linked in: >>> CPU: 2 PID: 21599 Comm: syz-executor3 Not tainted 4.11.0-rc8+ #1 >>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS >>> Ubuntu-1.8.2-1ubuntu1 04/01/2014 >>> task: ffff88006c16dec0 task.stack: ffff880058bb8000 >>> RIP: 0010:__read_once_size include/linux/compiler.h:254 [inline] >>> RIP: 0010:compound_head include/linux/page-flags.h:146 [inline] >>> RIP: 0010:put_page include/linux/mm.h:796 [inline] >>> RIP: 0010:__skb_frag_unref include/linux/skbuff.h:2613 [inline] >>> RIP: 0010:skb_release_data+0x201/0x3b0 net/core/skbuff.c:593 >>> RSP: 0018:ffff880058bbf570 EFLAGS: 00010a02 >>> RAX: 11032b488bad1523 RBX: ffff88006c6e8ec8 RCX: ffffc9000190e000 >>> RDX: 1ffff1000d8dd1df RSI: ffffffff8293d7e3 RDI: 88195a445d68a919 >>> RBP: ffff880058bbf5a8 R08: 7bdf27567b31597f R09: 0000000000000000 >>> R10: 00000000000000d2 R11: 7dc9ab6dec891f24 R12: 0000000000000000 >>> R13: dffffc0000000000 R14: ffff88006a475940 R15: 88195a445d68a8f9 >>> FS: 00007fbbc6a34700(0000) GS:ffff88006e400000(0000) knlGS:0000000000000000 >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>> CR2: 000000002004e000 CR3: 000000006b868000 CR4: 00000000000006e0 >>> Call Trace: >>> skb_release_all+0x4a/0x60 net/core/skbuff.c:669 >>> __kfree_skb net/core/skbuff.c:683 [inline] >>> kfree_skb+0x85/0x1b0 net/core/skbuff.c:704 >>> __ip6_append_data.isra.42+0x26ed/0x33b0 net/ipv6/ip6_output.c:1519 >>> ip6_append_data+0x1a8/0x2f0 net/ipv6/ip6_output.c:1633 >>> udpv6_sendmsg+0x7bd/0x2360 net/ipv6/udp.c:1264 >>> inet_sendmsg+0x123/0x3a0 net/ipv4/af_inet.c:762 >>> sock_sendmsg_nosec net/socket.c:633 [inline] >>> sock_sendmsg+0xca/0x110 net/socket.c:643 >>> ___sys_sendmsg+0x79f/0x900 net/socket.c:1997 >>> __sys_sendmsg+0xd1/0x170 net/socket.c:2031 >>> SYSC_sendmsg net/socket.c:2042 [inline] >>> SyS_sendmsg+0x2d/0x50 net/socket.c:2038 >>> entry_SYSCALL_64_fastpath+0x1a/0xa9 >>> RIP: 0033:0x44fb79 >>> RSP: 002b:00007fbbc6a33b58 EFLAGS: 00000212 ORIG_RAX: 000000000000002e >>> RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 000000000044fb79 >>> RDX: 0000000000000000 RSI: 000000002000afc8 RDI: 0000000000000005 >>> RBP: 00000000000003fb R08: 0000000000000000 R09: 0000000000000000 >>> R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000005 >>> R13: 0000000020001000 R14: 0000000000048000 R15: 0000000000000000 >>> Code: 48 83 c0 03 48 c1 e0 04 48 01 d8 48 89 c2 48 c1 ea 03 42 80 3c 2a 00 >>> 0f 85 92 01 00 00 4c 8b 38 49 8d 7f 20 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 >>> 0f 85 6f 01 00 00 49 8b 47 20 a8 01 0f 84 3b ff >>> RIP: __read_once_size include/linux/compiler.h:254 [inline] RSP: >>> ffff880058bbf570 >>> RIP: compound_head include/linux/page-flags.h:146 [inline] RSP: >>> ffff880058bbf570 >>> RIP: put_page include/linux/mm.h:796 [inline] RSP: ffff880058bbf570 >>> RIP: __skb_frag_unref include/linux/skbuff.h:2613 [inline] RSP: >>> ffff880058bbf570 >>> RIP: skb_release_data+0x201/0x3b0 net/core/skbuff.c:593 RSP: >>> ffff880058bbf570 >>> ---[ end trace 46c9f72a66cd8627 ]--- >>> Kernel panic - not syncing: Fatal exception >>> Dumping ftrace buffer: >>> (ftrace buffer empty) >>> Kernel Offset: disabled >>> Rebooting in 86400 seconds.. >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "syzkaller" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to syzkaller+unsubscr...@googlegroups.com. >>> For more options, visit https://groups.google.com/d/optout. > > Hi Andrey, please try following patch > Thanks.
Hi Eric, Your patch fixes the bug for me. Thanks! Tested-by: Andrey Konovalov <andreyk...@google.com> > > -- > You received this message because you are subscribed to the Google Groups > "syzkaller" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to syzkaller+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout.