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. > > 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. -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
