On Thu, Oct 19, 2017 at 8:13 PM, Wei Wei <dotwe...@gmail.com> wrote: > Sry. Here it is. > > Unable to handle kernel paging request at virtual address ffff80005bfb81ed > Mem abort info: > Exception class = DABT (current EL), IL = 32 bits > SET = 0, FnV = 0 > EA = 0, S1PTW = 0 > Data abort info: > ISV = 0, ISS = 0x00000033 > CM = 0, WnR = 0 > swapper pgtable: 4k pages, 48-bit VAs, pgd = ffff20000b366000 > [ffff80005bfb81ed] *pgd=00000000beff7003, *pud=00e8000080000711 > Internal error: Oops: 96000021 [#1] PREEMPT SMP > Modules linked in: > CPU: 3 PID: 4725 Comm: syz-executor0 Not tainted 4.14.0-rc3 #3 > Hardware name: linux,dummy-virt (DT) > task: ffff800074409e00 task.stack: ffff800033db0000 > PC is at __skb_clone (/./arch/arm64/include/asm/atomic_ll_sc.h:113 > (discriminator 4) /net/core/skbuff.c:873 (discriminator 4)) > LR is at __skb_clone (/net/core/skbuff.c:861 (discriminator 4)) > pc : lr : pstate: 10000145 > > sp : ffff800033db33d0 > x29: ffff800033db33d0 x28: ffff2000098ac378 > x27: ffff100006a860e1 x26: 1ffff000067b66b6 > x25: ffff8000743340a0 x24: ffff800035430708 > x23: ffff80005bfb80c9 x22: ffff800035430710 > x21: 0000000000000380 x20: ffff800035430640 > x19: ffff8000354312c0 x18: 0000000000000000 > x17: 00000000004af000 x16: ffff20000845e8c8 > x15: 000000001e518060 x14: 0000ffffd8316070 > x13: 0000ffffd8316090 x12: ffffffffffffffff > x11: 1ffff00006a8626f x10: ffff100006a8626f > x9 : dfff200000000000 x8 : 0082009000900608 > x7 : 0000000000000000 x6 : ffff800035431380 > x5 : ffff100006a86270 x4 : 0000000000000000 > x3 : 1ffff00006a86273 x2 : 0000000000000000 > x1 : 0000000000000100 x0 : ffff80005bfb81ed > Process syz-executor0 (pid: 4725, stack limit = 0xffff800033db0000) > Call trace: > Exception stack(0xffff800033db3290 to 0xffff800033db33d0) > 3280: ffff80005bfb81ed 0000000000000100 > 32a0: 0000000000000000 1ffff00006a86273 0000000000000000 ffff100006a86270 > 32c0: ffff800035431380 0000000000000000 0082009000900608 dfff200000000000 > 32e0: ffff100006a8626f 1ffff00006a8626f ffffffffffffffff 0000ffffd8316090 > 3300: 0000ffffd8316070 000000001e518060 ffff20000845e8c8 00000000004af000 > 3320: 0000000000000000 ffff8000354312c0 ffff800035430640 0000000000000380 > 3340: ffff800035430710 ffff80005bfb80c9 ffff800035430708 ffff8000743340a0 > 3360: 1ffff000067b66b6 ffff100006a860e1 ffff2000098ac378 ffff800033db33d0 > 3380: ffff200009705cfc ffff800033db33d0 ffff200009705f50 0000000010000145 > 33a0: ffff8000354312c0 ffff800035430640 0001000000000000 ffff800074334000 > 33c0: ffff800033db33d0 ffff200009705f50 > __skb_clone (/./arch/arm64/include/asm/atomic_ll_sc.h:113 (discriminator 4) > /net/core/skbuff.c:873 (discriminator 4)) > skb_clone (/net/core/skbuff.c:1286) > arp_rcv (/./include/linux/skbuff.h:1518 /net/ipv4/arp.c:946) > __netif_receive_skb_core (/net/core/dev.c:1859 /net/core/dev.c:1874 > /net/core/dev.c:4416) > __netif_receive_skb (/net/core/dev.c:4466) > netif_receive_skb_internal (/net/core/dev.c:4539) > netif_receive_skb (/net/core/dev.c:4564) > tun_get_user (/./include/linux/bottom_half.h:31 /drivers/net/tun.c:1219 > /drivers/net/tun.c:1553) > tun_chr_write_iter (/drivers/net/tun.c:1579) > do_iter_readv_writev (/./include/linux/fs.h:1770 /fs/read_write.c:673) > do_iter_write (/fs/read_write.c:952) > vfs_writev (/fs/read_write.c:997) > do_writev (/fs/read_write.c:1032) > SyS_writev (/fs/read_write.c:1102) > Exception stack(0xffff800033db3ec0 to 0xffff800033db4000) > 3ec0: 0000000000000015 0000ffff829985e0 0000000000000001 0000ffff8299851c > 3ee0: 0000ffff82999068 0000ffff82998f60 0000ffff82999650 0000000000000000 > 3f00: 0000000000000042 0000000000000036 0000000000406608 0000ffff82998400 > 3f20: 0000ffff82998f60 0000ffffd8316090 0000ffffd8316070 000000001e518060 > 3f40: 0000000000000000 00000000004af000 0000000000000000 0000000000000036 > 3f60: 0000000020004fca 0000000020000000 000000000046ccf0 0000000000000530 > 3f80: 000000000046cce8 00000000004ade98 0000000000000000 00000000395fa6f0 > 3fa0: 0000ffff82998f60 0000ffff82998560 0000000000431448 0000ffff82998520 > 3fc0: 000000000043145c 0000000080000000 0000000000000015 0000000000000042 > 3fe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > el0_svc_naked (/arch/arm64/kernel/entry.S:853) > Code: f9406680 8b010000 91009000 f9800011 (885f7c01) > All code > ======== > 0: 80 66 40 f9 andb $0xf9,0x40(%rsi) > 4: 00 00 add %al,(%rax) > 6: 01 8b 00 90 00 91 add %ecx,-0x6eff7000(%rbx) > c: 11 00 adc %eax,(%rax) > e: 80 f9 01 cmp $0x1,%cl > 11: 7c 5f jl 0x72 > 13:* 88 00 mov %al,(%rax) <-- trapping > instruction > 15: 00 00 add %al,(%rax) > ... > > Code starting with the faulting instruction > =========================================== > 0: 01 7c 5f 88 add %edi,-0x78(%rdi,%rbx,2) > 4: 00 00 add %al,(%rax) > ... > —[ end trace 261e7ac1458ccc0a ]--- >
I thought it was happening on arm64 ? This is x86_64 disassembly :/ Thanks. > Thanks, > Wei > >> On 19 Oct 2017, at 10:53 PM, Eric Dumazet <eduma...@google.com> wrote: >> >> On Thu, Oct 19, 2017 at 7:16 PM, Wei Wei <dotwe...@gmail.com> wrote: >>> Hi all, >>> >>> I have fuzzed v4.14-rc3 using syzkaller and found a bug similar to that one >>> [1]. >>> But the call trace isn’t the same. The atomic_inc() might handle a corrupted >>> skb_buff. >>> >>> The logs and config have been uploaded to my github repo [2]. >>> >>> [1] https://lkml.org/lkml/2017/10/2/216 >>> [2] https://github.com/dotweiba/skb_clone_atomic_inc_bug >>> >>> Thanks, >>> Wei >>> >>> Unable to handle kernel paging request at virtual address ffff80005bfb81ed >>> Mem abort info: >>> Exception class = DABT (current EL), IL = 32 bits >>> SET = 0, FnV = 0 >>> EA = 0, S1PTW = 0 >>> Data abort info: >>> ISV = 0, ISS = 0x00000033 >>> CM = 0, WnR = 0 >>> swapper pgtable: 4k pages, 48-bit VAs, pgd = ffff20000b366000 >>> [ffff80005bfb81ed] *pgd=00000000beff7003, *pud=00e8000080000711 >>> Internal error: Oops: 96000021 [#1] PREEMPT SMP >>> Modules linked in: >>> CPU: 3 PID: 4725 Comm: syz-executor0 Not tainted 4.14.0-rc3 #3 >>> Hardware name: linux,dummy-virt (DT) >>> task: ffff800074409e00 task.stack: ffff800033db0000 >>> PC is at __skb_clone+0x430/0x5b0 >>> LR is at __skb_clone+0x1dc/0x5b0 >>> pc : [<ffff200009705f50>] lr : [<ffff200009705cfc>] pstate: 10000145 >>> sp : ffff800033db33d0 >>> x29: ffff800033db33d0 x28: ffff2000098ac378 >>> x27: ffff100006a860e1 x26: 1ffff000067b66b6 >>> x25: ffff8000743340a0 x24: ffff800035430708 >>> x23: ffff80005bfb80c9 x22: ffff800035430710 >>> x21: 0000000000000380 x20: ffff800035430640 >>> x19: ffff8000354312c0 x18: 0000000000000000 >>> x17: 00000000004af000 x16: ffff20000845e8c8 >>> x15: 000000001e518060 x14: 0000ffffd8316070 >>> x13: 0000ffffd8316090 x12: ffffffffffffffff >>> x11: 1ffff00006a8626f x10: ffff100006a8626f >>> x9 : dfff200000000000 x8 : 0082009000900608 >>> x7 : 0000000000000000 x6 : ffff800035431380 >>> x5 : ffff100006a86270 x4 : 0000000000000000 >>> x3 : 1ffff00006a86273 x2 : 0000000000000000 >>> x1 : 0000000000000100 x0 : ffff80005bfb81ed >>> Process syz-executor0 (pid: 4725, stack limit = 0xffff800033db0000) >>> Call trace: >>> Exception stack(0xffff800033db3290 to 0xffff800033db33d0) >>> 3280: ffff80005bfb81ed 0000000000000100 >>> 32a0: 0000000000000000 1ffff00006a86273 0000000000000000 ffff100006a86270 >>> 32c0: ffff800035431380 0000000000000000 0082009000900608 dfff200000000000 >>> 32e0: ffff100006a8626f 1ffff00006a8626f ffffffffffffffff 0000ffffd8316090 >>> 3300: 0000ffffd8316070 000000001e518060 ffff20000845e8c8 00000000004af000 >>> 3320: 0000000000000000 ffff8000354312c0 ffff800035430640 0000000000000380 >>> 3340: ffff800035430710 ffff80005bfb80c9 ffff800035430708 ffff8000743340a0 >>> 3360: 1ffff000067b66b6 ffff100006a860e1 ffff2000098ac378 ffff800033db33d0 >>> 3380: ffff200009705cfc ffff800033db33d0 ffff200009705f50 0000000010000145 >>> 33a0: ffff8000354312c0 ffff800035430640 0001000000000000 ffff800074334000 >>> 33c0: ffff800033db33d0 ffff200009705f50 >>> [<ffff200009705f50>] __skb_clone+0x430/0x5b0 >>> [<ffff20000971520c>] skb_clone+0x164/0x2c8 >>> [<ffff2000098ac498>] arp_rcv+0x120/0x488 >>> [<ffff200009741878>] __netif_receive_skb_core+0x11e8/0x18c8 >>> [<ffff2000097479b0>] __netif_receive_skb+0x30/0x198 >>> [<ffff200009751fd8>] netif_receive_skb_internal+0x98/0x370 >>> [<ffff2000097522cc>] netif_receive_skb+0x1c/0x28 >>> [<ffff2000090730e0>] tun_get_user+0x12f0/0x2e40 >>> [<ffff200009074ddc>] tun_chr_write_iter+0xbc/0x140 >>> [<ffff200008457284>] do_iter_readv_writev+0x2d4/0x468 >>> [<ffff20000845a5a0>] do_iter_write+0x148/0x498 >>> [<ffff20000845aac0>] vfs_writev+0x118/0x250 >>> [<ffff20000845acbc>] do_writev+0xc4/0x1e8 >>> [<ffff20000845e8fc>] SyS_writev+0x34/0x48 >>> Exception stack(0xffff800033db3ec0 to 0xffff800033db4000) >>> 3ec0: 0000000000000015 0000ffff829985e0 0000000000000001 0000ffff8299851c >>> 3ee0: 0000ffff82999068 0000ffff82998f60 0000ffff82999650 0000000000000000 >>> 3f00: 0000000000000042 0000000000000036 0000000000406608 0000ffff82998400 >>> 3f20: 0000ffff82998f60 0000ffffd8316090 0000ffffd8316070 000000001e518060 >>> 3f40: 0000000000000000 00000000004af000 0000000000000000 0000000000000036 >>> 3f60: 0000000020004fca 0000000020000000 000000000046ccf0 0000000000000530 >>> 3f80: 000000000046cce8 00000000004ade98 0000000000000000 00000000395fa6f0 >>> 3fa0: 0000ffff82998f60 0000ffff82998560 0000000000431448 0000ffff82998520 >>> 3fc0: 000000000043145c 0000000080000000 0000000000000015 0000000000000042 >>> 3fe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 >>> [<ffff200008083ef0>] el0_svc_naked+0x24/0x28 >>> Code: f9406680 8b010000 91009000 f9800011 (885f7c01) >>> ---[ end trace 261e7ac1458ccc0a ]--- >> >> Please provide proper file:line information in this trace. >> >> You can use scripts/decode_stacktrace.sh >> >> Thanks. >
