On Tue, Apr 9, 2019 at 4:23 PM Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote: > > On Thu, Feb 22, 2018 at 10:50 AM Xin Long <lucien.xin@xxxxxxxxx> wrote: > > > > On Wed, Feb 21, 2018 at 9:59 PM, syzbot > > <syzbot+98a809ad0f54884bde26@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > > Hello, > > > > > > syzbot hit the following crash on upstream commit > > > 79c0ef3e85c015b0921a8fd5dd539d1480e9cd6c (Mon Feb 19 19:58:19 2018 +0000) > > > Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net > > > > > > So far this crash happened 2 times on > > > https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/master. > > > 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+98a809ad0f54884bde26@xxxxxxxxxxxxxxxxxxxxxxxxx > > > 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. > > > > > > IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready > > > IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready > > > audit: type=1400 audit(1519151768.973:11): avc: denied { sys_chroot } for > > > pid=4169 comm="syz-executor5" capability=18 > > > scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 > > > tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns > > > permissive=1 > > > ------------[ cut here ]------------ > > > refcount_t: underflow; use-after-free. > > > WARNING: CPU: 0 PID: 5074 at lib/refcount.c:187 > > > refcount_sub_and_test+0x167/0x1b0 lib/refcount.c:187 > > > Kernel panic - not syncing: panic_on_warn set ... > > It seems that we also need to process the chunks in > > outqueue->control_chunk_list in sctp_for_each_tx_datachunk() > > when peeling off. > > Hi Xin, > > Did you mail any fix for this? No, I realized it doesn't make difference to add the process for control_chunk_list in sctp_for_each_tx_datachunk(). > The bug is still open, but the crash did not happen in the past > months. It seems that 3 different bugs accumulated in this bug: there > was a splash of crashes in Feb 2018, then it stopped crashing, then > some crashes in May 2018, probably a different bug, then stopped > happening again, then another splash in Nov 2018, most likely a > different bugs, then it stopped happening again. If we keep it open, > it will continue accumulating more different bugs. We've had some fixes for peeling off process added in the latest kernel since then, which could be related. So I think we can close this one now, and let's see what the new bugs will look like. Thanks. > > > > > > CPU: 0 PID: 5074 Comm: syz-executor5 Not tainted 4.16.0-rc2+ #322 > > > 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 > > > panic+0x1e4/0x41c kernel/panic.c:183 > > > __warn+0x1dc/0x200 kernel/panic.c:547 > > > report_bug+0x211/0x2d0 lib/bug.c:184 > > > fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178 > > > fixup_bug arch/x86/kernel/traps.c:247 [inline] > > > do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 > > > do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 > > > invalid_op+0x58/0x80 arch/x86/entry/entry_64.S:957 > > > RIP: 0010:refcount_sub_and_test+0x167/0x1b0 lib/refcount.c:187 > > > RSP: 0018:ffff8801cf2b6490 EFLAGS: 00010282 > > > RAX: dffffc0000000008 RBX: 0000000000000401 RCX: ffffffff815abdbe > > > RDX: 0000000000000000 RSI: 1ffff10039e56c42 RDI: 1ffff10039e56c17 > > > RBP: ffff8801cf2b6520 R08: 1ffff10039e56bd9 R09: 0000000000000000 > > > R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10039e56c93 > > > R13: 00000000ffffff01 R14: 0000000000000500 R15: ffff8801ae3c69fc > > > sock_wfree+0xa6/0x140 net/core/sock.c:1819 > > > sctp_wfree+0x2eb/0x670 net/sctp/socket.c:8065 > > > skb_release_head_state+0x124/0x260 net/core/skbuff.c:612 > > > skb_release_all+0x15/0x60 net/core/skbuff.c:625 > > > __kfree_skb net/core/skbuff.c:641 [inline] > > > consume_skb+0x153/0x490 net/core/skbuff.c:701 > > > sctp_chunk_destroy net/sctp/sm_make_chunk.c:1450 [inline] > > > sctp_chunk_put+0x29c/0x420 net/sctp/sm_make_chunk.c:1477 > > > sctp_chunk_free+0x53/0x60 net/sctp/sm_make_chunk.c:1464 > > > __sctp_outq_teardown+0x244/0x1230 net/sctp/outqueue.c:234 > > > sctp_outq_free+0x15/0x20 net/sctp/outqueue.c:291 > > > sctp_association_free+0x2d0/0x930 net/sctp/associola.c:356 > > > sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:939 [inline] > > > sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1343 [inline] > > > sctp_side_effects net/sctp/sm_sideeffect.c:1210 [inline] > > > sctp_do_sm+0x32e3/0x6ed0 net/sctp/sm_sideeffect.c:1181 > > > sctp_primitive_ABORT+0xa0/0xd0 net/sctp/primitive.c:119 > > > sctp_close+0x266/0x9a0 net/sctp/socket.c:1539 > > > inet_release+0xed/0x1c0 net/ipv4/af_inet.c:427 > > > sock_release+0x8d/0x1e0 net/socket.c:595 > > > sock_close+0x16/0x20 net/socket.c:1149 > > > __fput+0x327/0x7e0 fs/file_table.c:209 > > > ____fput+0x15/0x20 fs/file_table.c:243 > > > task_work_run+0x199/0x270 kernel/task_work.c:113 > > > exit_task_work include/linux/task_work.h:22 [inline] > > > do_exit+0x9bb/0x1ad0 kernel/exit.c:865 > > > do_group_exit+0x149/0x400 kernel/exit.c:968 > > > get_signal+0x73a/0x16d0 kernel/signal.c:2469 > > > do_signal+0x90/0x1e90 arch/x86/kernel/signal.c:809 > > > exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:162 > > > prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] > > > syscall_return_slowpath arch/x86/entry/common.c:265 [inline] > > > do_syscall_64+0x6e5/0x940 arch/x86/entry/common.c:292 > > > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > > > RIP: 0033:0x453da9 > > > RSP: 002b:00007f297546ace8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca > > > RAX: fffffffffffffe00 RBX: 000000000072bf80 RCX: 0000000000453da9 > > > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000072bf80 > > > RBP: 000000000072bf80 R08: 0000000000000000 R09: 000000000072bf58 > > > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > > > R13: 0000000000a3e8ef R14: 00007f297546b9c0 R15: 0000000000000001 > > > Dumping ftrace buffer: > > > (ftrace buffer empty) > > > Kernel Offset: disabled > > > Rebooting in 86400 seconds.. > > > > > > > > > --- > > > This bug is generated by a dumb bot. It may contain errors. > > > See https://goo.gl/tpsmEJ for details. > > > Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. > > > > > > 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. > > > > -- > > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/CADvbK_eandMH1aZvKnzdX%3D3xdS0NSo6_NAeCrKasqA9EON4B0A%40mail.gmail.com. > > For more options, visit https://groups.google.com/d/optout.
