Messages in this thread | | | From | Dmitry Vyukov <> | Date | Tue, 25 Feb 2020 16:12:08 +0100 | Subject | Re: BUG: unable to handle kernel NULL pointer dereference in cipso_v4_sock_setattr |
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On Tue, Feb 25, 2020 at 4:09 PM Dmitry Vyukov <dvyukov@google.com> wrote: > > > > > Hello, > > > > > > > > > > syzbot found the following crash on: > > > > > > > > > > HEAD commit: ca7e1fd1 Merge tag 'linux-kselftest-5.6-rc3' of git://git... > > > > > git tree: upstream > > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=179f0931e00000 > > > > > kernel config: https://syzkaller.appspot.com/x/.config?x=a61f2164c515c07f > > > > > dashboard link: https://syzkaller.appspot.com/bug?extid=f4dfece964792d80b139 > > > > > compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > > > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14fdfdede00000 > > > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17667de9e00000 > > > > > > > > > > The bug was bisected to: > > > > > > > > > > commit 2303f994b3e187091fd08148066688b08f837efc > > > > > Author: Peter Krystad <peter.krystad@linux.intel.com> > > > > > Date: Wed Jan 22 00:56:17 2020 +0000 > > > > > > > > > > mptcp: Associate MPTCP context with TCP socket > > > > > > > > > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14fbec81e00000 > > > > > final crash: https://syzkaller.appspot.com/x/report.txt?x=16fbec81e00000 > > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=12fbec81e00000 > > > > > > > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > > > > Reported-by: syzbot+f4dfece964792d80b139@syzkaller.appspotmail.com > > > > > Fixes: 2303f994b3e1 ("mptcp: Associate MPTCP context with TCP socket") > > > > > > > > > > BUG: kernel NULL pointer dereference, address: 0000000000000000 > > > > > #PF: supervisor instruction fetch in kernel mode > > > > > #PF: error_code(0x0010) - not-present page > > > > > PGD 8e171067 P4D 8e171067 PUD 93fa2067 PMD 0 > > > > > Oops: 0010 [#1] PREEMPT SMP KASAN > > > > > CPU: 0 PID: 8984 Comm: syz-executor066 Not tainted 5.6.0-rc2-syzkaller #0 > > > > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > > > > RIP: 0010:0x0 > > > > > Code: Bad RIP value. > > > > > RSP: 0018:ffffc900020b7b80 EFLAGS: 00010246 > > > > > RAX: 1ffff110124ba600 RBX: 0000000000000000 RCX: ffff88809fefa600 > > > > > RDX: ffff8880994cdb18 RSI: 0000000000000000 RDI: ffff8880925d3140 > > > > > RBP: ffffc900020b7bd8 R08: ffffffff870225be R09: fffffbfff140652a > > > > > R10: fffffbfff140652a R11: 0000000000000000 R12: ffff8880925d35d0 > > > > > R13: ffff8880925d3140 R14: dffffc0000000000 R15: 1ffff110124ba6ba > > > > > FS: 0000000001a0b880(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 > > > > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > > CR2: ffffffffffffffd6 CR3: 00000000a6d6f000 CR4: 00000000001406f0 > > > > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > > > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > > > Call Trace: > > > > > cipso_v4_sock_setattr+0x34b/0x470 net/ipv4/cipso_ipv4.c:1888 > > > > > netlbl_sock_setattr+0x2a7/0x310 net/netlabel/netlabel_kapi.c:989 > > > > > smack_netlabel security/smack/smack_lsm.c:2425 [inline] > > > > > smack_inode_setsecurity+0x3da/0x4a0 security/smack/smack_lsm.c:2716 > > > > > security_inode_setsecurity+0xb2/0x140 security/security.c:1364 > > > > > __vfs_setxattr_noperm+0x16f/0x3e0 fs/xattr.c:197 > > > > > vfs_setxattr fs/xattr.c:224 [inline] > > > > > setxattr+0x335/0x430 fs/xattr.c:451 > > > > > __do_sys_fsetxattr fs/xattr.c:506 [inline] > > > > > __se_sys_fsetxattr+0x130/0x1b0 fs/xattr.c:495 > > > > > __x64_sys_fsetxattr+0xbf/0xd0 fs/xattr.c:495 > > > > > do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 > > > > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > > > > > > > Netdev folks, I'm not very familiar with the multipath TCP code so I > > > > was wondering if you might help me out a bit with this report. Based > > > > on the stack trace above it looks like for a given AF_INET sock "sk", > > > > inet_sk(sk)->is_icsk is true but inet_csk(sk) is NULL; should this be > > > > possible under normal conditions or is there an issue somewhere? > > > > > > Paolo has submitted some patch for testing for this bug, not sure if > > > you have seen it, just in case: > > > https://groups.google.com/forum/#!msg/syzkaller-bugs/dqwnTBh-MQw/LhgSZYGsBgAJ > > > > I sent the patch to the syzbot ML only, for testing before posting on > > netdev, so Paul likely have not seen it yet, sorry. > > > > @Dmitry: I did not get any reply yet from syzbot, are there any > > problems or is this the usual time-frame? > > The testing is queued after bisection of this guy: > https://syzkaller.appspot.com/bug?id=c0a75a31c5fa84e6e5d3131fd98a5b56e2141b9a > which has been running since 6pm yesterday...
It's stuck in this boot-broken region. And git bisect degrades to linear behavior on skipped commits (why?). If only kernel would have proper presubmit testing to avoid at least boot breakages... :)
[ 6.784292][ T24] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 6.787429][ T24] general protection fault: 0000 [#1] PREEMPT SMP KASAN [ 6.789312][ T24] CPU: 1 PID: 24 Comm: kworker/u4:2 Not tainted 5.3.0-rc1-syzkaller #0 [ 6.791623][ T24] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 6.791623][ T24] Workqueue: events_unbound async_run_entry_fn [ 6.795328][ T24] RIP: 0010:dma_direct_max_mapping_size+0x5d/0x128 [ 6.795328][ T24] Code: df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 c2 00 00 00 4c 8b a3 38 03 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 aa 00 00 00 48 8d bb 48 03 00 00 4d 8b 2c 24 48 [ 6.795328][ T24] RSP: 0000:ffff8880a9adf728 EFLAGS: 00010246 [ 6.806015][ T24] RAX: dffffc0000000000 RBX: ffff88821962b300 RCX: ffffffff8716d938 [ 6.806015][ T24] RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff88821962b638 [ 6.806015][ T24] RBP: ffff8880a9adf740 R08: ffffed101443d28d R09: ffffed101443d28d [ 6.806015][ T24] R10: ffffed101443d28c R11: ffff8880a21e9467 R12: 0000000000000000 [ 6.806015][ T24] R13: ffff88821962b300 R14: ffff8880a28a6a70 R15: 0000000000000200 [ 6.818295][ T24] FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 [ 6.818446][ T24] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6.818446][ T24] CR2: 0000000000000000 CR3: 0000000008a6d000 CR4: 00000000001406e0 [ 6.818446][ T24] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 6.818446][ T24] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 6.829410][ T24] Call Trace: [ 6.829410][ T24] dma_max_mapping_size+0xa2/0xc0 [ 6.831705][ T24] __scsi_init_queue+0x197/0x4f0 [ 6.831705][ T24] scsi_mq_alloc_queue+0xb7/0x150 [ 6.831705][ T24] scsi_alloc_sdev+0x7b7/0xb80 [ 6.831705][ T24] scsi_probe_and_add_lun+0x86a/0x37c0 [ 6.831705][ T24] ? __kasan_check_read+0x11/0x20 [ 6.839613][ T24] ? scsi_alloc_sdev+0xb80/0xb80 [ 6.839613][ T24] ? mark_lock+0xc3/0x1190 [ 6.839613][ T24] ? mark_held_locks+0xb8/0x130 [ 6.839613][ T24] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 6.839613][ T24] ? __pm_runtime_resume+0xb4/0x110 [ 6.839613][ T24] ? lockdep_hardirqs_on+0x424/0x5c0 [ 6.839613][ T24] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 6.839613][ T24] ? trace_hardirqs_on+0x28/0x1a0 [ 6.851380][ T1] slram: not enough parameters. [ 6.839613][ T24] ? _raw_spin_unlock_irqrestore+0x6d/0xd0 [ 6.839613][ T24] ? __pm_runtime_resume+0xb4/0x110 [ 6.839613][ T24] __scsi_scan_target+0x1fd/0xc90 [ 6.839613][ T24] ? scsi_add_device+0x30/0x30 [ 6.839613][ T24] ? mark_held_locks+0xb8/0x130 [ 6.839613][ T24] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 6.839613][ T24] ? __pm_runtime_resume+0xb4/0x110 [ 6.839613][ T24] ? lockdep_hardirqs_on+0x424/0x5c0 [ 6.839613][ T24] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 6.839613][ T24] ? trace_hardirqs_on+0x28/0x1a0 [ 6.839613][ T24] scsi_scan_channel.part.8+0xd6/0x140 [ 6.857364][ T1] ftl_cs: FTL header not found. [ 6.854615][ T24] scsi_scan_host_selected+0x20c/0x300 [ 6.865470][ T1] Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011) [ 6.854615][ T24] ? scsi_scan_host+0x3c0/0x3c0 [ 6.854615][ T24] do_scsi_scan_host+0x1b3/0x250 [ 6.854615][ T24] ? lock_downgrade+0x900/0x900 [ 6.854615][ T24] ? scsi_scan_host+0x3c0/0x3c0 [ 6.854615][ T24] do_scan_async+0x3c/0x450 [ 6.854615][ T24] ? scsi_scan_host+0x3c0/0x3c0 [ 6.854615][ T24] async_run_entry_fn+0xf9/0x4b0 [ 6.854615][ T24] process_one_work+0x856/0x1630 [ 6.854615][ T24] ? pwq_dec_nr_in_flight+0x2c0/0x2c0 [ 6.854615][ T24] ? lock_acquire+0x194/0x410 [ 6.854615][ T24] worker_thread+0x85/0xb60 [ 6.854615][ T24] ? __kthread_parkme+0x47/0x1a0 [ 6.854615][ T24] kthread+0x331/0x3f0 [ 6.854615][ T24] ? process_one_work+0x1630/0x1630 [ 6.854615][ T24] ? kthread_cancel_delayed_work_sync+0x10/0x10 [ 6.854615][ T24] ret_from_fork+0x24/0x30 [ 6.854615][ T24] Modules linked in: [ 6.907103][ T24] ---[ end trace 14068796cd600dc6 ]--- [ 6.908603][ T24] RIP: 0010:dma_direct_max_mapping_size+0x5d/0x128 [ 6.909683][ T1] eql: Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com) [ 6.910361][ T24] Code: df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 c2 00 00 00 4c 8b a3 38 03 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 aa 00 00 00 48 8d bb 48 03 00 00 4d 8b 2c 24 48 [ 6.918535][ T24] RSP: 0000:ffff8880a9adf728 EFLAGS: 00010246 [ 6.919167][ T1] MACsec IEEE 802.1AE [ 6.920089][ T24] RAX: dffffc0000000000 RBX: ffff88821962b300 RCX: ffffffff8716d938 [ 6.921513][ T1] tun: Universal TUN/TAP device driver, 1.6 [ 6.923553][ T24] RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff88821962b638 [ 6.932178][ T24] RBP: ffff8880a9adf740 R08: ffffed101443d28d R09: ffffed101443d28d [ 6.946172][ T24] R10: ffffed101443d28c R11: ffff8880a21e9467 R12: 0000000000000000 [ 6.952330][ T24] R13: ffff88821962b300 R14: ffff8880a28a6a70 R15: 0000000000000200 [ 6.956636][ T24] FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 [ 6.964469][ T24] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6.968832][ T24] CR2: 0000000000000000 CR3: 0000000008a6d000 CR4: 00000000001406e0 [ 6.971517][ T24] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 6.977961][ T24] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 6.983019][ T24] Kernel panic - not syncing: Fatal exception [ 6.983346][ T1] vcan: Virtual CAN interface driver [ 6.987331][ T24] Kernel Offset: disabled [ 6.988609][ T24] Rebooting in 86400 seconds..
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