Re: KMSAN: uninit-value in netif_skb_features
On 2018/04/12 17:03, Dmitry Vyukov wrote: > On Thu, Apr 12, 2018 at 10:01 AM, syzbot > wrote: >> Hello, >> >> syzbot hit the following crash on https://github.com/google/kmsan.git/master >> commit >> e2ab7e8abba47a2f2698216258e5d8727ae58717 (Fri Apr 6 16:24:31 2018 +) >> kmsan: temporarily disable visitAsmInstruction() to help syzbot >> syzbot dashboard link: >> https://syzkaller.appspot.com/bug?extid=0bbe42c764feafa82c5a >> >> So far this crash happened 30 times on >> https://github.com/google/kmsan.git/master. >> C reproducer: https://syzkaller.appspot.com/x/repro.c?id=4850744041668608 >> syzkaller reproducer: >> https://syzkaller.appspot.com/x/repro.syz?id=6289386287136768 >> Raw console output: >> https://syzkaller.appspot.com/x/log.txt?id=4577411249209344 >> Kernel config: >> https://syzkaller.appspot.com/x/.config?id=6627248707860932248 >> compiler: clang version 7.0.0 (trunk 329391) > > +Toshiaki as this seems to be related to the recent vlan tagging changes. Seems not. Probably skb_vlan_tagged_multi() needs to call pskb_may_pull() before accessing skb->data? I'll confirm it later. > This also seems to be related to > https://groups.google.com/d/msg/syzkaller-bugs/FNEavkB4QaM/efXl2AeRBgAJ > > > >> IMPORTANT: if you fix the bug, please add the following tag to the commit: >> Reported-by: syzbot+0bbe42c764feafa82...@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: KMSAN: uninit-value in eth_type_vlan include/linux/if_vlan.h:283 >> [inline] >> BUG: KMSAN: uninit-value in skb_vlan_tagged_multi >> include/linux/if_vlan.h:656 [inline] >> BUG: KMSAN: uninit-value in vlan_features_check include/linux/if_vlan.h:672 >> [inline] >> BUG: KMSAN: uninit-value in dflt_features_check net/core/dev.c:2949 [inline] >> BUG: KMSAN: uninit-value in netif_skb_features+0xd1b/0xdc0 >> net/core/dev.c:3009 >> CPU: 1 PID: 3582 Comm: syzkaller435149 Not tainted 4.16.0+ #82 >> 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+0x185/0x1d0 lib/dump_stack.c:53 >> kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 >> __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676 >> eth_type_vlan include/linux/if_vlan.h:283 [inline] >> skb_vlan_tagged_multi include/linux/if_vlan.h:656 [inline] >> vlan_features_check include/linux/if_vlan.h:672 [inline] >> dflt_features_check net/core/dev.c:2949 [inline] >> netif_skb_features+0xd1b/0xdc0 net/core/dev.c:3009 >> validate_xmit_skb+0x89/0x1320 net/core/dev.c:3084 >> __dev_queue_xmit+0x1cb2/0x2b60 net/core/dev.c:3549 >> dev_queue_xmit+0x4b/0x60 net/core/dev.c:3590 >> packet_snd net/packet/af_packet.c:2944 [inline] >> packet_sendmsg+0x7c57/0x8a10 net/packet/af_packet.c:2969 >> sock_sendmsg_nosec net/socket.c:630 [inline] >> sock_sendmsg net/socket.c:640 [inline] >> sock_write_iter+0x3b9/0x470 net/socket.c:909 >> do_iter_readv_writev+0x7bb/0x970 include/linux/fs.h:1776 >> do_iter_write+0x30d/0xd40 fs/read_write.c:932 >> vfs_writev fs/read_write.c:977 [inline] >> do_writev+0x3c9/0x830 fs/read_write.c:1012 >> SYSC_writev+0x9b/0xb0 fs/read_write.c:1085 >> SyS_writev+0x56/0x80 fs/read_write.c:1082 >> do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 >> entry_SYSCALL_64_after_hwframe+0x3d/0xa2 >> RIP: 0033:0x43ffa9 >> RSP: 002b:7fff2cff3948 EFLAGS: 0217 ORIG_RAX: 0014 >> RAX: ffda RBX: 004002c8 RCX: 0043ffa9 >> RDX: 0001 RSI: 2080 RDI: 0003 >> RBP: 006cb018 R08: R09: >> R10: R11: 0217 R12: 004018d0 >> R13: 00401960 R14: R15: >> >> Uninit was created at: >> kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] >> kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188 >> kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314 >> kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321 >> slab_post_alloc_hook mm/slab.h:445 [inline] >> slab_alloc_node mm/slub.c:2737 [inline] >> __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369 >> __kmalloc_reserve net/core/skbuff.c:138 [inline] >> __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:20
Re: KMSAN: uninit-value in netif_skb_features
On Thu, Apr 12, 2018 at 10:01 AM, syzbot wrote: > Hello, > > syzbot hit the following crash on https://github.com/google/kmsan.git/master > commit > e2ab7e8abba47a2f2698216258e5d8727ae58717 (Fri Apr 6 16:24:31 2018 +) > kmsan: temporarily disable visitAsmInstruction() to help syzbot > syzbot dashboard link: > https://syzkaller.appspot.com/bug?extid=0bbe42c764feafa82c5a > > So far this crash happened 30 times on > https://github.com/google/kmsan.git/master. > C reproducer: https://syzkaller.appspot.com/x/repro.c?id=4850744041668608 > syzkaller reproducer: > https://syzkaller.appspot.com/x/repro.syz?id=6289386287136768 > Raw console output: > https://syzkaller.appspot.com/x/log.txt?id=4577411249209344 > Kernel config: > https://syzkaller.appspot.com/x/.config?id=6627248707860932248 > compiler: clang version 7.0.0 (trunk 329391) +Toshiaki as this seems to be related to the recent vlan tagging changes. This also seems to be related to https://groups.google.com/d/msg/syzkaller-bugs/FNEavkB4QaM/efXl2AeRBgAJ > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+0bbe42c764feafa82...@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: KMSAN: uninit-value in eth_type_vlan include/linux/if_vlan.h:283 > [inline] > BUG: KMSAN: uninit-value in skb_vlan_tagged_multi > include/linux/if_vlan.h:656 [inline] > BUG: KMSAN: uninit-value in vlan_features_check include/linux/if_vlan.h:672 > [inline] > BUG: KMSAN: uninit-value in dflt_features_check net/core/dev.c:2949 [inline] > BUG: KMSAN: uninit-value in netif_skb_features+0xd1b/0xdc0 > net/core/dev.c:3009 > CPU: 1 PID: 3582 Comm: syzkaller435149 Not tainted 4.16.0+ #82 > 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+0x185/0x1d0 lib/dump_stack.c:53 > kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 > __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676 > eth_type_vlan include/linux/if_vlan.h:283 [inline] > skb_vlan_tagged_multi include/linux/if_vlan.h:656 [inline] > vlan_features_check include/linux/if_vlan.h:672 [inline] > dflt_features_check net/core/dev.c:2949 [inline] > netif_skb_features+0xd1b/0xdc0 net/core/dev.c:3009 > validate_xmit_skb+0x89/0x1320 net/core/dev.c:3084 > __dev_queue_xmit+0x1cb2/0x2b60 net/core/dev.c:3549 > dev_queue_xmit+0x4b/0x60 net/core/dev.c:3590 > packet_snd net/packet/af_packet.c:2944 [inline] > packet_sendmsg+0x7c57/0x8a10 net/packet/af_packet.c:2969 > sock_sendmsg_nosec net/socket.c:630 [inline] > sock_sendmsg net/socket.c:640 [inline] > sock_write_iter+0x3b9/0x470 net/socket.c:909 > do_iter_readv_writev+0x7bb/0x970 include/linux/fs.h:1776 > do_iter_write+0x30d/0xd40 fs/read_write.c:932 > vfs_writev fs/read_write.c:977 [inline] > do_writev+0x3c9/0x830 fs/read_write.c:1012 > SYSC_writev+0x9b/0xb0 fs/read_write.c:1085 > SyS_writev+0x56/0x80 fs/read_write.c:1082 > do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x3d/0xa2 > RIP: 0033:0x43ffa9 > RSP: 002b:7fff2cff3948 EFLAGS: 0217 ORIG_RAX: 0014 > RAX: ffda RBX: 004002c8 RCX: 0043ffa9 > RDX: 0001 RSI: 2080 RDI: 0003 > RBP: 006cb018 R08: R09: > R10: R11: 0217 R12: 004018d0 > R13: 00401960 R14: R15: > > Uninit was created at: > kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] > kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188 > kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314 > kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321 > slab_post_alloc_hook mm/slab.h:445 [inline] > slab_alloc_node mm/slub.c:2737 [inline] > __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369 > __kmalloc_reserve net/core/skbuff.c:138 [inline] > __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206 > alloc_skb include/linux/skbuff.h:984 [inline] > alloc_skb_with_frags+0x1d4/0xb20 net/core/skbuff.c:5234 > sock_alloc_send_pskb+0xb56/0x1190 net/core/sock.c:2085 > packet_alloc_skb net/packet/af_packet.c:2803 [inline] > packet_snd net/packet/af_packet.c:2894 [inline] > packet_sendmsg+0x6444/0x8a10 net/packet/af_packet.c:2969 > sock_sendmsg_nosec net/socket.c:630 [inline] > sock_sendmsg net/socket.c:640 [inline] > sock_write_iter+0x3b9/0x470 net/socket.c:909 > do_iter_readv_writev+0x7bb/0x970 include/li
KMSAN: uninit-value in netif_skb_features
Hello, syzbot hit the following crash on https://github.com/google/kmsan.git/master commit e2ab7e8abba47a2f2698216258e5d8727ae58717 (Fri Apr 6 16:24:31 2018 +) kmsan: temporarily disable visitAsmInstruction() to help syzbot syzbot dashboard link: https://syzkaller.appspot.com/bug?extid=0bbe42c764feafa82c5a So far this crash happened 30 times on https://github.com/google/kmsan.git/master. C reproducer: https://syzkaller.appspot.com/x/repro.c?id=4850744041668608 syzkaller reproducer: https://syzkaller.appspot.com/x/repro.syz?id=6289386287136768 Raw console output: https://syzkaller.appspot.com/x/log.txt?id=4577411249209344 Kernel config: https://syzkaller.appspot.com/x/.config?id=6627248707860932248 compiler: clang version 7.0.0 (trunk 329391) IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+0bbe42c764feafa82...@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: KMSAN: uninit-value in eth_type_vlan include/linux/if_vlan.h:283 [inline] BUG: KMSAN: uninit-value in skb_vlan_tagged_multi include/linux/if_vlan.h:656 [inline] BUG: KMSAN: uninit-value in vlan_features_check include/linux/if_vlan.h:672 [inline] BUG: KMSAN: uninit-value in dflt_features_check net/core/dev.c:2949 [inline] BUG: KMSAN: uninit-value in netif_skb_features+0xd1b/0xdc0 net/core/dev.c:3009 CPU: 1 PID: 3582 Comm: syzkaller435149 Not tainted 4.16.0+ #82 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+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676 eth_type_vlan include/linux/if_vlan.h:283 [inline] skb_vlan_tagged_multi include/linux/if_vlan.h:656 [inline] vlan_features_check include/linux/if_vlan.h:672 [inline] dflt_features_check net/core/dev.c:2949 [inline] netif_skb_features+0xd1b/0xdc0 net/core/dev.c:3009 validate_xmit_skb+0x89/0x1320 net/core/dev.c:3084 __dev_queue_xmit+0x1cb2/0x2b60 net/core/dev.c:3549 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3590 packet_snd net/packet/af_packet.c:2944 [inline] packet_sendmsg+0x7c57/0x8a10 net/packet/af_packet.c:2969 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] sock_write_iter+0x3b9/0x470 net/socket.c:909 do_iter_readv_writev+0x7bb/0x970 include/linux/fs.h:1776 do_iter_write+0x30d/0xd40 fs/read_write.c:932 vfs_writev fs/read_write.c:977 [inline] do_writev+0x3c9/0x830 fs/read_write.c:1012 SYSC_writev+0x9b/0xb0 fs/read_write.c:1085 SyS_writev+0x56/0x80 fs/read_write.c:1082 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x43ffa9 RSP: 002b:7fff2cff3948 EFLAGS: 0217 ORIG_RAX: 0014 RAX: ffda RBX: 004002c8 RCX: 0043ffa9 RDX: 0001 RSI: 2080 RDI: 0003 RBP: 006cb018 R08: R09: R10: R11: 0217 R12: 004018d0 R13: 00401960 R14: R15: Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314 kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321 slab_post_alloc_hook mm/slab.h:445 [inline] slab_alloc_node mm/slub.c:2737 [inline] __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:984 [inline] alloc_skb_with_frags+0x1d4/0xb20 net/core/skbuff.c:5234 sock_alloc_send_pskb+0xb56/0x1190 net/core/sock.c:2085 packet_alloc_skb net/packet/af_packet.c:2803 [inline] packet_snd net/packet/af_packet.c:2894 [inline] packet_sendmsg+0x6444/0x8a10 net/packet/af_packet.c:2969 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] sock_write_iter+0x3b9/0x470 net/socket.c:909 do_iter_readv_writev+0x7bb/0x970 include/linux/fs.h:1776 do_iter_write+0x30d/0xd40 fs/read_write.c:932 vfs_writev fs/read_write.c:977 [inline] do_writev+0x3c9/0x830 fs/read_write.c:1012 SYSC_writev+0x9b/0xb0 fs/read_write.c:1085 SyS_writev+0x56/0x80 fs/read_write.c:1082 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 == --- 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
