bisecting cause commit starting from 494d311a82bb06a81fa7ef4277367701a792e6ef building syzkaller on 6436ce4bcd8e2c7dcca0b171ac91f51e96d973f8 testing commit 494d311a82bb06a81fa7ef4277367701a792e6ef with gcc (GCC) 8.1.0 kernel signature: 316955eae2ad8b44be27e81987540e1d212cecb0b91a466ec74cf26bfe61a22f run #0: crashed: INFO: task can't die in p9_fd_close run #1: crashed: INFO: task can't die in p9_fd_close run #2: crashed: INFO: task can't die in p9_fd_close run #3: crashed: INFO: task can't die in p9_fd_close run #4: crashed: INFO: task can't die in p9_fd_close run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: OK run #8: OK run #9: OK testing release v5.8 testing commit bcf876870b95592b52519ed4aafcf9d95999bc9c with gcc (GCC) 8.1.0 kernel signature: 85e63852cb58fb07567d271eede7efacb769d51315bd9eafff3ec035b343fc61 run #0: crashed: INFO: task hung in p9_fd_close run #1: crashed: no output from test machine run #2: crashed: no output from test machine run #3: OK run #4: OK run #5: boot failed: can't ssh into the instance run #6: OK run #7: OK run #8: OK run #9: OK testing release v5.7 testing commit 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 with gcc (GCC) 8.1.0 kernel signature: 165a2738b699c44fc41a0d62b38f86b5227906471ae34b61c67c833e08e36d43 run #0: crashed: INFO: task hung in p9_fd_close run #1: crashed: no output from test machine run #2: crashed: no output from test machine run #3: crashed: no output from test machine run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v5.6 testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.1.0 kernel signature: e62b1f85e4b8898b4936ccef4dcb17a52c3adcc9b16c1907772d29e0963c4163 run #0: crashed: INFO: task hung in p9_fd_close run #1: crashed: INFO: task hung in p9_fd_close run #2: crashed: INFO: task hung in p9_fd_close run #3: crashed: INFO: task hung in p9_fd_close run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v5.5 testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0 kernel signature: 1114393809ebbe49f22f42e5b72c8a122758a25b42228daafdb0ff07ccb96873 all runs: crashed: no output from test machine testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0 kernel signature: 6e559ffd6ca1400ea3a5cf094a2a86b9b9979ae40e223d03b67a56aac558cac4 run #0: crashed: INFO: task hung in p9_fd_close run #1: crashed: INFO: task hung in p9_fd_close run #2: crashed: INFO: task hung in p9_fd_close run #3: crashed: INFO: task hung in p9_fd_close run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0 kernel signature: d21b3d6e3e16d9a7aa8914f029b2d25e0ceef5da2c5bd8c3da9f81ff26863350 run #0: crashed: INFO: task hung in p9_fd_close run #1: crashed: INFO: task hung in p9_fd_close run #2: crashed: no output from test machine run #3: crashed: no output from test machine run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 kernel signature: ff2abe85c4cca64de942d3e802f3f7443c29c539482184d4f922daa46da2bbd9 run #0: crashed: INFO: task hung in p9_fd_close run #1: crashed: INFO: task hung in p9_fd_close run #2: crashed: INFO: task hung in p9_fd_close run #3: crashed: INFO: task hung in p9_fd_close run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v5.1 testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0 kernel signature: 0b2fcde8d2b098be9dacef202254f917592b865645d785f416d84882647305a8 run #0: crashed: INFO: task hung in p9_fd_close run #1: crashed: INFO: task hung in p9_fd_close run #2: crashed: INFO: task hung in p9_fd_close run #3: crashed: no output from test machine run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: OK testing release v5.0 testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0 kernel signature: afa56cb24f743361704c1b0abbc9c828ce66668abd7c7ea6618bb0cb106c1efc run #0: crashed: INFO: task hung in p9_fd_close run #1: crashed: INFO: task hung in p9_fd_close run #2: crashed: no output from test machine run #3: crashed: no output from test machine run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.20 testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0 kernel signature: 1ffbc54bb3711cf9071395c479c22fa09add8d317095b8eb47b6278d9196ee25 run #0: crashed: INFO: task hung in p9_fd_close run #1: crashed: no output from test machine run #2: crashed: no output from test machine run #3: crashed: no output from test machine run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: OK testing release v4.19 testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0 kernel signature: 56aa6a67de400a331bb7cd0afddacef4841b44423689bdb8f8e24c5268d2152a run #0: crashed: INFO: task hung in p9_fd_close run #1: crashed: INFO: task hung in p9_fd_close run #2: crashed: no output from test machine run #3: crashed: no output from test machine run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: OK run #8: OK run #9: OK testing release v4.18 testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0 kernel signature: 943ac642cca1b9c759538d1343079246efef023cdf6a1599c3e8369b3ecf922e run #0: crashed: no output from test machine run #1: crashed: no output from test machine run #2: crashed: no output from test machine run #3: crashed: no output from test machine run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: INFO: task hung in p9_fd_close run #7: OK run #8: OK run #9: OK testing release v4.17 testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.1.0 kernel signature: 35d95b6125ec00112bcaca06e8685f76cbc97c3437df80d13b1d98fc30ecf781 run #0: crashed: INFO: task hung in p9_fd_close run #1: crashed: no output from test machine run #2: crashed: no output from test machine run #3: crashed: no output from test machine run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0 kernel signature: 8ff331523dce3d7ae6368e72f2a80b682bd51b813eb4c674acc13bcbe792e3a2 all runs: OK # git bisect start 29dcea88779c856c7dc92040a0c01233263101d4 0adb32858b0bddf4ada5f364a84ed60b196dbcda Bisecting: 7380 revisions left to test after this (roughly 13 steps) [97b1255cb27c551d7c3c5c496d787da40772da99] mm,oom_reaper: check for MMF_OOM_SKIP before complaining testing commit 97b1255cb27c551d7c3c5c496d787da40772da99 with gcc (GCC) 8.1.0 kernel signature: a6f4b44b8b2e82f705c8673f629e69db062d6bd5b501852b4e11aaf757eeb809 all runs: OK # git bisect good 97b1255cb27c551d7c3c5c496d787da40772da99 Bisecting: 3715 revisions left to test after this (roughly 12 steps) [5e630afdcb82779f5bf03fd4a5e86adc56fe7c8a] Merge tag 'fbdev-v4.17' of git://github.com/bzolnier/linux testing commit 5e630afdcb82779f5bf03fd4a5e86adc56fe7c8a with gcc (GCC) 8.1.0 kernel signature: e2fa6b56dac88c722596a617b9d5979f39dd6ffe36f69e93cabdcba805a296bb run #0: crashed: INFO: task hung in p9_fd_close run #1: crashed: no output from test machine run #2: crashed: no output from test machine run #3: crashed: KASAN: use-after-free Read in p9_conn_cancel run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: INFO: task hung in p9_fd_close run #8: OK run #9: OK # git bisect bad 5e630afdcb82779f5bf03fd4a5e86adc56fe7c8a Bisecting: 1658 revisions left to test after this (roughly 11 steps) [b240b419db5d624ce7a5a397d6f62a1a686009ec] Merge tag 'armsoc-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc testing commit b240b419db5d624ce7a5a397d6f62a1a686009ec with gcc (GCC) 8.1.0 kernel signature: e6347f9b319572876bd12176f8565287ad49931ffa576c79c07866ab155d471d run #0: crashed: no output from test machine run #1: crashed: no output from test machine run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad b240b419db5d624ce7a5a397d6f62a1a686009ec Bisecting: 1070 revisions left to test after this (roughly 10 steps) [3526dd0c7832f1011a0477cc6d903662bae05ea8] Merge tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block testing commit 3526dd0c7832f1011a0477cc6d903662bae05ea8 with gcc (GCC) 8.1.0 kernel signature: 3c95aa552c1b80ecde16f40bdbdb7366a3ec62ce7ff7c6d0a3afd39c33a9bada run #0: crashed: no output from test machine run #1: OK run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad 3526dd0c7832f1011a0477cc6d903662bae05ea8 Bisecting: 464 revisions left to test after this (roughly 9 steps) [4ec7e204ea8bde75a55add9877b9ab3a9784aab1] Merge remote-tracking branches 'asoc/topic/tda7419', 'asoc/topic/tfa9879', 'asoc/topic/tlv320aic23', 'asoc/topic/tlv320aic26' and 'asoc/topic/tlv320aic31xx' into asoc-next testing commit 4ec7e204ea8bde75a55add9877b9ab3a9784aab1 with gcc (GCC) 8.1.0 kernel signature: e346b0ccec81b097871189d3357cd2df96dfadd66889df3b50729b55652e3ae7 run #0: crashed: no output from test machine run #1: OK run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad 4ec7e204ea8bde75a55add9877b9ab3a9784aab1 Bisecting: 231 revisions left to test after this (roughly 8 steps) [5eed6fe345c2fd48cc07c9c354c8453b4ce977fc] Merge remote-tracking branches 'asoc/topic/adav80x', 'asoc/topic/ads117x', 'asoc/topic/ak4104', 'asoc/topic/ak4458' and 'asoc/topic/ak4535' into asoc-next testing commit 5eed6fe345c2fd48cc07c9c354c8453b4ce977fc with gcc (GCC) 8.1.0 kernel signature: 3ba2f0c451f0b813060fba03d388b7fe0d0a7eb2999b200e7d9f188be69804a8 all runs: OK # git bisect good 5eed6fe345c2fd48cc07c9c354c8453b4ce977fc Bisecting: 115 revisions left to test after this (roughly 7 steps) [89314dbf6188f59feb43b904b73fff95d5bb2cd8] Merge remote-tracking branches 'asoc/topic/hdmi-codec', 'asoc/topic/ics43432', 'asoc/topic/imx-wm8962' and 'asoc/topic/inno_rk3036' into asoc-next testing commit 89314dbf6188f59feb43b904b73fff95d5bb2cd8 with gcc (GCC) 8.1.0 kernel signature: 0dbc658cb8d6b2e3c74b4afb436e89e592bbf1f5a44927b4f478b5e9bec0a2a5 run #0: crashed: INFO: task hung in p9_fd_close run #1: crashed: no output from test machine run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad 89314dbf6188f59feb43b904b73fff95d5bb2cd8 Bisecting: 57 revisions left to test after this (roughly 6 steps) [651c939fdc3c9ea42aa84a2b5ff217f6199a313d] Merge remote-tracking branches 'asoc/topic/cs42l73', 'asoc/topic/cs42xx8', 'asoc/topic/cs43130', 'asoc/topic/cs4349' and 'asoc/topic/cs53l30' into asoc-next testing commit 651c939fdc3c9ea42aa84a2b5ff217f6199a313d with gcc (GCC) 8.1.0 kernel signature: af9a3f928a29712fc681b8e6b640645a96b38c4d82f6845b32bf88e63e1870c8 run #0: crashed: no output from test machine run #1: OK run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad 651c939fdc3c9ea42aa84a2b5ff217f6199a313d Bisecting: 32 revisions left to test after this (roughly 5 steps) [6f4103b645ce1acf46c97a843e60ca21c5830218] Merge remote-tracking branches 'asoc/topic/ak5386', 'asoc/topic/ak5558', 'asoc/topic/alc5623', 'asoc/topic/alc5632' and 'asoc/topic/amd' into asoc-next testing commit 6f4103b645ce1acf46c97a843e60ca21c5830218 with gcc (GCC) 8.1.0 kernel signature: 8c694e31fddeaa70ac0e990ca9836f08f14eb0a207781fb47f3c919d9a7bfb47 run #0: crashed: no output from test machine run #1: OK run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad 6f4103b645ce1acf46c97a843e60ca21c5830218 Bisecting: 15 revisions left to test after this (roughly 4 steps) [4c50e1e3e2c29899c0226f7ad56d7266e814f2b3] ASoC: amd: don't use codec anymore testing commit 4c50e1e3e2c29899c0226f7ad56d7266e814f2b3 with gcc (GCC) 8.1.0 kernel signature: 38edfed996723babaa8812fbe6248ece234beb8da835f52da4639c45481e2dde all runs: OK # git bisect good 4c50e1e3e2c29899c0226f7ad56d7266e814f2b3 Bisecting: 7 revisions left to test after this (roughly 3 steps) [7212b7b61e8cb1bc67ff1f2837cc161e1b01ff7f] Merge remote-tracking branches 'asoc/topic/ak4554', 'asoc/topic/ak4613', 'asoc/topic/ak4641', 'asoc/topic/ak4642' and 'asoc/topic/ak4671' into asoc-next testing commit 7212b7b61e8cb1bc67ff1f2837cc161e1b01ff7f with gcc (GCC) 8.1.0 kernel signature: 97c5315f43dedc403c985d05026f168af3257874856231df96e648917f71ca11 all runs: OK # git bisect good 7212b7b61e8cb1bc67ff1f2837cc161e1b01ff7f Bisecting: 3 revisions left to test after this (roughly 2 steps) [af3acca3e35c01920fe476f730dca7345d0a48df] ASoC: ak5558: Fix style for SPDX identifier testing commit af3acca3e35c01920fe476f730dca7345d0a48df with gcc (GCC) 8.1.0 kernel signature: f90d2932c1a93ca16a3c16aff9663aee8c3dc977ebcabb1a8e992c3f27346a1a run #0: crashed: no output from test machine run #1: crashed: INFO: task hung in p9_fd_close run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad af3acca3e35c01920fe476f730dca7345d0a48df Bisecting: 1 revision left to test after this (roughly 1 step) [af0424e44c180d66c2ddfb0a99c52382de8f69f8] ASoC: ak5558: Add bindings for AK5558 ADC testing commit af0424e44c180d66c2ddfb0a99c52382de8f69f8 with gcc (GCC) 8.1.0 kernel signature: f4bedf957102dcb0f9d63f64213d7940bf8ef8ac16f68c2b53724436479146cf all runs: OK # git bisect good af0424e44c180d66c2ddfb0a99c52382de8f69f8 Bisecting: 0 revisions left to test after this (roughly 0 steps) [3f15aa198fb88a6a0db8c7ba136637d566effb55] ASoC: ak5558: replace codec to component testing commit 3f15aa198fb88a6a0db8c7ba136637d566effb55 with gcc (GCC) 8.1.0 kernel signature: 2dce8108a8c61053c9dbd3b8fb3d6961dc18632ad0cdf7ad1a09e83a66537888 all runs: OK # git bisect good 3f15aa198fb88a6a0db8c7ba136637d566effb55 af3acca3e35c01920fe476f730dca7345d0a48df is the first bad commit commit af3acca3e35c01920fe476f730dca7345d0a48df Author: Daniel Baluta Date: Tue Feb 20 14:53:10 2018 +0200 ASoC: ak5558: Fix style for SPDX identifier Use // for .c and /* for .h files according to: Documentation/process/license-rules.rst file. Signed-off-by: Daniel Baluta Signed-off-by: Mark Brown sound/soc/codecs/ak5558.c | 11 +++++------ sound/soc/codecs/ak5558.h | 4 ++-- 2 files changed, 7 insertions(+), 8 deletions(-) culprit signature: f90d2932c1a93ca16a3c16aff9663aee8c3dc977ebcabb1a8e992c3f27346a1a parent signature: 2dce8108a8c61053c9dbd3b8fb3d6961dc18632ad0cdf7ad1a09e83a66537888 revisions tested: 29, total time: 7h40m6.621907014s (build: 2h41m41.182361187s, test: 4h55m11.345308548s) first bad commit: af3acca3e35c01920fe476f730dca7345d0a48df ASoC: ak5558: Fix style for SPDX identifier recipients (to): ["alsa-devel@alsa-project.org" "broonie@kernel.org" "broonie@kernel.org" "daniel.baluta@nxp.com" "lgirdwood@gmail.com" "perex@perex.cz" "tiwai@suse.com"] recipients (cc): ["linux-kernel@vger.kernel.org"] crash: INFO: task hung in p9_fd_close NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 INFO: task syz-executor.4:6779 blocked for more than 140 seconds. Not tainted 4.16.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28040 6779 6421 0x00000004 Call Trace: context_switch kernel/sched/core.c:2857 [inline] __schedule+0x832/0x1f00 kernel/sched/core.c:3435 schedule+0x7f/0x1b0 kernel/sched/core.c:3494 schedule_timeout+0x70e/0xd20 kernel/time/timer.c:1777 do_wait_for_common kernel/sched/completion.c:86 [inline] __wait_for_common kernel/sched/completion.c:107 [inline] wait_for_common+0x3fb/0x5d0 kernel/sched/completion.c:118 wait_for_completion+0x18/0x20 kernel/sched/completion.c:139 flush_work+0x361/0x700 kernel/workqueue.c:2871 __cancel_work_timer+0x30c/0x440 kernel/workqueue.c:2942 cancel_work_sync+0xb/0x10 kernel/workqueue.c:2978 p9_conn_destroy net/9p/trans_fd.c:870 [inline] p9_fd_close+0x263/0x400 net/9p/trans_fd.c:896 p9_client_destroy+0x61/0x540 net/9p/client.c:1094 v9fs_session_close+0x3d/0x2a0 fs/9p/v9fs.c:490 v9fs_kill_super+0x49/0x90 fs/9p/vfs_super.c:233 deactivate_locked_super+0x62/0xb0 fs/super.c:312 v9fs_mount+0x366/0x770 fs/9p/vfs_super.c:214 mount_fs+0x7f/0x2a9 fs/super.c:1222 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1037 vfs_kern_mount fs/namespace.c:1027 [inline] do_new_mount fs/namespace.c:2512 [inline] do_mount+0x366/0x2b30 fs/namespace.c:2842 SYSC_mount fs/namespace.c:3058 [inline] SyS_mount+0xb1/0xd0 fs/namespace.c:3035 do_syscall_64+0x1c9/0x6a0 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x26/0x9b RIP: 0033:0x45d4d9 RSP: 002b:00007f447743bc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000021180 RCX: 000000000045d4d9 RDX: 0000000020000200 RSI: 0000000020000000 RDI: 0000000000000000 RBP: 000000000118cf90 R08: 00000000200028c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffc9a1ed1ff R14: 00007f447743c9c0 R15: 000000000118cf4c Showing all locks held in the system: 2 locks held by kworker/0:0/3: #0: ((wq_completion)"events"){+.+.}, at: [<00000000916b0bd7>] process_one_work+0x699/0x1510 kernel/workqueue.c:2084 #1: ((work_completion)(&m->wq)){+.+.}, at: [<00000000354a8438>] process_one_work+0x6cc/0x1510 kernel/workqueue.c:2088 2 locks held by khungtaskd/1062: #0: (rcu_read_lock){....}, at: [<00000000fc4519fc>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000fc4519fc>] watchdog+0xfc/0x8d0 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000294b4621>] debug_show_all_locks+0x79/0x222 kernel/locking/lockdep.c:4470 1 lock held by in:imklog/5960: #0: (&f->f_pos_lock){+.+.}, at: [<00000000375bd1b5>] __fdget_pos+0x8e/0xc0 fs/file.c:765 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1062 Comm: khungtaskd Not tainted 4.16.0-rc1-syzkaller #0 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+0x141/0x1e1 lib/dump_stack.c:53 nmi_cpu_backtrace.cold.0+0x13/0xb7 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0xf4/0x118 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x598/0x8d0 kernel/hung_task.c:249 kthread+0x316/0x3d0 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:429 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5 Comm: kworker/u4:0 Not tainted 4.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:rcu_read_lock_sched_held+0x88/0x120 kernel/rcu/update.c:112 RSP: 0018:ffff8800aec07ce0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff885463a0 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffff8800a9c7ca48 RDI: ffff8800a9c7c9f4 RBP: ffff8800aec07ce8 R08: ffff8800a9c7ca68 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800a50db050 R13: ffff8800aec07d98 R14: 1ffff10015d80fa3 R15: ffff8800a50db050 FS: 0000000000000000(0000) GS:ffff8800aec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f744203f000 CR3: 0000000099c26000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_timer_expire_exit include/trace/events/timer.h:121 [inline] call_timer_fn+0x458/0x590 kernel/time/timer.c:1327 expire_timers+0x268/0x3f0 kernel/time/timer.c:1363 __run_timers kernel/time/timer.c:1666 [inline] run_timer_softirq+0x1dc/0x530 kernel/time/timer.c:1692 __do_softirq+0x247/0x96d kernel/softirq.c:285 invoke_softirq kernel/softirq.c:365 [inline] irq_exit+0x18e/0x1e0 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:541 [inline] smp_apic_timer_interrupt+0x126/0x5b0 arch/x86/kernel/apic/apic.c:1052 apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:829 RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:772 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:794 [inline] RIP: 0010:lock_acquire+0x96/0x3e0 kernel/locking/lockdep.c:3915 RSP: 0018:ffff8800a9c97c98 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff12 RAX: dffffc0000000000 RBX: ffff8800a9c7c140 RCX: 0000000000000000 RDX: 1ffffffff10226ec RSI: 0000000000000000 RDI: ffffffff88113760 RBP: ffff8800a9c97ce0 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8800a9c7ca48 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:244 [inline] rcu_read_lock include/linux/rcupdate.h:630 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:419 [inline] batadv_nc_worker+0xef/0x630 net/batman-adv/network-coding.c:730 process_one_work+0x76a/0x1510 kernel/workqueue.c:2113 worker_thread+0xcc/0xed0 kernel/workqueue.c:2247 kthread+0x316/0x3d0 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:429 Code: 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 7d 8b 15 cd 6f 07 07 85 d2 74 09 e8 d4 fc ff ff 85 c0 75 08 b8 01 00 00 00 5b 5d c3 93 77 00 00 84 c0 74 4b e8 ca df 00 00 84 c0 74 42 48 b8 00