------- Comment on attachment From chngu...@us.ibm.com 2018-05-12 22:40 EDT-------
System crashes after 2nd attempt for few hours but the dump is not completed and the guest is not coming back. The console log shows more details where system is at...... ** Attachment added: "sol console log" https://bugs.launchpad.net/bugs/1770784/+attachment/5138580/+files/boslcp4g4.0512.txt -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1770784 Title: ISST-LTE:KVM:Ubuntu1804:BostonLC:boslcp4g4:ubuntu1604:P8 compat: guest crashes in apparmor_file_alloc_security() Status in linux package in Ubuntu: New Bug description: Test was running an Ubuntu 16.04 guest with a Ubuntu 18.04 host when the guest dumped a vmcore. According to the dump, the crash is actually a BUG_ON() raised from apparmor_file_alloc_security() having called aa_begin_current_label() which calls aa_current_raw_label() that in turn calls aa_cred_raw_label() where the BUG_ON() resides: static inline struct aa_label *aa_cred_raw_label(const struct cred *cred) { struct aa_task_ctx *ctx = cred_ctx(cred); BUG_ON(!ctx || !ctx->label); return ctx->label; } Now, the warnings we previously had seen raised from aa_file_perm() may have been related since rcu_dereference() as fctx->label is NULL. fctx = file_ctx(file); rcu_read_lock(); flabel = rcu_dereference(fctx->label); AA_BUG(!flabel); KERNEL: /usr/lib/debug/boot/vmlinux-4.4.0-124-generic DUMPFILE: dump.201805110830 [PARTIAL DUMP] CPUS: 32 DATE: Fri May 11 06:30:35 2018 UPTIME: 03:40:43 LOAD AVERAGE: 102.77, 103.38, 100.54 TASKS: 862 NODENAME: boslcp4g4 RELEASE: 4.4.0-124-generic VERSION: #148-Ubuntu SMP Wed May 2 13:02:22 UTC 2018 MACHINE: ppc64le (2134 Mhz) MEMORY: 16 GB PANIC: "kernel BUG at /build/linux-VRGJAN/linux-4.4.0/security/apparmor/include/context.h:69!" PID: 18397 COMMAND: "chgrp" TASK: c00000035be322c0 [THREAD_INFO: c00000035b5c0000] CPU: 10 STATE: TASK_RUNNING (PANIC) crash> bt PID: 18397 TASK: c00000035be322c0 CPU: 10 COMMAND: "chgrp" #0 [c00000035b5c3430] crash_kexec at c000000000176274 #1 [c00000035b5c35d0] die at c000000000020ef8 #2 [c00000035b5c3660] _exception at c000000000021244 #3 [c00000035b5c37f0] program_check_common at c000000000006208 Program Check [700] exception frame: R0: c0000000004923e4 R1: c00000035b5c3ae0 R2: c0000000015fa700 R3: c0000000fcd01a00 R4: 0000000000000001 R5: ffffffffffffffc0 R6: c0000000fcd01b00 R7: 00000003fe8d0000 R8: c00000000163a700 R9: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: c0000000004fd880 R13: c000000007b06400 R14: 0000000000000000 R15: 0000000000000000 R16: 0000000000000013 R17: 0000000000000000 R18: 00003fffb7501468 R19: 0000000000000000 R20: 00003fffb74ff7e0 R21: 0000000000000000 R22: 0000000000000000 R23: 00003fffdf3cbd40 R24: ffffffff90000001 R25: 0000000000000041 R26: fffffffffffff000 R27: c00000035b5c3dd0 R28: c0000000016342f8 R29: c0000000fcd01a00 R30: c0000000fcd01a00 R31: 0000000000000000 NIP: c0000000004fd8c8 MSR: 8000000000029033 OR3: c0000000004923e0 CTR: c0000000004fd880 LR: c0000000004923e4 XER: 0000000000000000 CCR: 0000000024004248 MQ: 0000000000000001 DAR: c000000328004288 DSISR: c00000035b5c39e0 Syscall Result: 0000000000000000 #4 [c00000035b5c3ae0] apparmor_file_alloc_security at c0000000004fd8c8 [Link Register] [c00000035b5c3ae0] security_file_alloc at c0000000004923e4 #5 [c00000035b5c3b50] security_file_alloc at c0000000004923e4 (unreliable) #6 [c00000035b5c3b90] get_empty_filp at c0000000002e7010 #7 [c00000035b5c3c10] path_openat at c0000000002faa2c #8 [c00000035b5c3c90] do_filp_open at c0000000002fc9bc #9 [c00000035b5c3db0] do_sys_open at c0000000002e3150 #10 [c00000035b5c3e30] system_call at c000000000009484 System Call [c01] exception frame: R0: 0000000000000005 R1: 00003fffdf3cb8c0 R2: 00003fffb7507e00 R3: 00000100270514b0 R4: 0000000000080000 R5: 00003fffb7501ef8 R6: 0000000000000008 R7: ffffffff90000001 R8: 00003fffdf3cbd40 R9: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 00003fffb750a190 NIP: 00003fffb74dbdac MSR: 800000000280f033 OR3: 00000100270514b0 CTR: 0000000000000000 LR: 00003fffb74b7034 XER: 0000000000000000 CCR: 0000000044004442 MQ: 0000000000000001 DAR: 00003fffb7480000 DSISR: 0000000040000000 Syscall Result: fffffffffffffffe To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1770784/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
