bisecting cause commit starting from 7f206cf3ec2bee4621325cfacb2588e5085c07f5 building syzkaller on 76f7fc952d5c6a94c61aa2628568ffddb533272a testing commit 7f206cf3ec2bee4621325cfacb2588e5085c07f5 with gcc (GCC) 10.2.1 20210217 kernel signature: 5730584c85dab76816c5b5d09f8599238f7716578ced6a23860458df27151b11 all runs: crashed: general protection fault in try_to_wake_up testing release v5.11 testing commit f40ddce88593482919761f74910f42f4b84c004b with gcc (GCC) 10.2.1 20210217 kernel signature: b47e4715276950756b03b5ad9dbf4728b20992193d0763caa8c0112f7aa0328d all runs: OK # git bisect start 7f206cf3ec2bee4621325cfacb2588e5085c07f5 f40ddce88593482919761f74910f42f4b84c004b Bisecting: 6695 revisions left to test after this (roughly 13 steps) [10e2ec8edece2566b40f69bae035a555ece71ab4] Merge tag 'sound-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound testing commit 10e2ec8edece2566b40f69bae035a555ece71ab4 with gcc (GCC) 10.2.1 20210217 kernel signature: a5207523c95a618801b0b5f3c1bd78a84107e0c7029f09f00448e34397f8e672 all runs: OK # git bisect good 10e2ec8edece2566b40f69bae035a555ece71ab4 Bisecting: 3349 revisions left to test after this (roughly 12 steps) [54ab35d6bbc0d3175b0a74282c3365c80a43a93c] Merge tag 'livepatching-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching testing commit 54ab35d6bbc0d3175b0a74282c3365c80a43a93c with gcc (GCC) 10.2.1 20210217 kernel signature: 10c9e618eb22b0f496825c04c2a629c55443fd43367d771543a926a4fcce7652 all runs: OK # git bisect good 54ab35d6bbc0d3175b0a74282c3365c80a43a93c Bisecting: 1698 revisions left to test after this (roughly 11 steps) [489f270ad4bd81818faea212a625ae45a38875dd] Merge remote-tracking branch 'arm/for-next' testing commit 489f270ad4bd81818faea212a625ae45a38875dd with gcc (GCC) 10.2.1 20210217 kernel signature: d09e0cf7a790ac758487cda12398b87f2c037f201e763719636d038d79c18827 all runs: OK # git bisect good 489f270ad4bd81818faea212a625ae45a38875dd Bisecting: 850 revisions left to test after this (roughly 10 steps) [48c1e1e01bc2f6963e646940bebe3bf0377bfce0] Merge remote-tracking branch 'v4l-dvb-next/master' testing commit 48c1e1e01bc2f6963e646940bebe3bf0377bfce0 with gcc (GCC) 10.2.1 20210217 kernel signature: cb040a540dc10e1a557e8555db713f693f834dffbda6c5234f5d560cf986484d all runs: OK # git bisect good 48c1e1e01bc2f6963e646940bebe3bf0377bfce0 Bisecting: 430 revisions left to test after this (roughly 9 steps) [925ab8fc6faa96624dfdfeb45afdd6fcfebac102] Merge remote-tracking branch 'rpmsg/for-next' testing commit 925ab8fc6faa96624dfdfeb45afdd6fcfebac102 with gcc (GCC) 10.2.1 20210217 kernel signature: 38e12c0ff2666dc428e4051a24a144b256e0fa641912a9a24061dad2156befcf all runs: crashed: general protection fault in try_to_wake_up # git bisect bad 925ab8fc6faa96624dfdfeb45afdd6fcfebac102 Bisecting: 180 revisions left to test after this (roughly 8 steps) [43dfa4fac8c15ddd070c518dd44db9b111b0c0c2] Merge remote-tracking branch 'block/for-next' testing commit 43dfa4fac8c15ddd070c518dd44db9b111b0c0c2 with gcc (GCC) 10.2.1 20210217 kernel signature: fe9968a3a1da2207d2e502e1bc8dacbb556920bb6a7fff9cd6767b69978f856f all runs: crashed: general protection fault in try_to_wake_up # git bisect bad 43dfa4fac8c15ddd070c518dd44db9b111b0c0c2 Bisecting: 94 revisions left to test after this (roughly 7 steps) [95c72a23fef4915390dd2780876276fda09e2af9] Merge remote-tracking branch 'amdgpu/drm-next' testing commit 95c72a23fef4915390dd2780876276fda09e2af9 with gcc (GCC) 10.2.1 20210217 kernel signature: a0da15b65fe7e3618377d9a4b9398141651703b61258ed0c107a8b35f5a02001 all runs: OK # git bisect good 95c72a23fef4915390dd2780876276fda09e2af9 Bisecting: 47 revisions left to test after this (roughly 6 steps) [a1639a434b2045d7f9f90df6b651b99b2f0d5c8a] io-wq: fix races around manager/worker creation and task exit testing commit a1639a434b2045d7f9f90df6b651b99b2f0d5c8a with gcc (GCC) 10.2.1 20210217 kernel signature: af755857338a2dc447438f6636b07895a37f9e32e3c4822af5bd463abb4259c2 run #0: crashed: KASAN: use-after-free Read in try_to_wake_up run #1: crashed: KASAN: use-after-free Read in try_to_wake_up run #2: crashed: KASAN: use-after-free Read in try_to_wake_up run #3: crashed: SYZFAIL: wrong response packet run #4: crashed: KASAN: use-after-free Read in try_to_wake_up run #5: crashed: KASAN: use-after-free Read in try_to_wake_up run #6: crashed: KASAN: use-after-free Read in try_to_wake_up run #7: crashed: SYZFAIL: wrong response packet run #8: crashed: KASAN: use-after-free Read in try_to_wake_up run #9: crashed: KASAN: use-after-free Read in try_to_wake_up # git bisect bad a1639a434b2045d7f9f90df6b651b99b2f0d5c8a Bisecting: 23 revisions left to test after this (roughly 5 steps) [7c25c0d16ef3c37e49c593ac92f69fa3884d4bb9] io_uring: remove the need for relying on an io-wq fallback worker testing commit 7c25c0d16ef3c37e49c593ac92f69fa3884d4bb9 with gcc (GCC) 10.2.1 20210217 kernel signature: 1a2901351ff5ea1733acd7ab331e7560085cbdd629f031ea7df909dc2bd0e33b run #0: crashed: SYZFAIL: wrong response packet 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 reproducer seems to be flaky # git bisect bad 7c25c0d16ef3c37e49c593ac92f69fa3884d4bb9 Bisecting: 11 revisions left to test after this (roughly 4 steps) [1ee43ba8d267b5e6729c45b8756263f69c2978cc] io_uring: don't do async setup for links' heads testing commit 1ee43ba8d267b5e6729c45b8756263f69c2978cc with gcc (GCC) 10.2.1 20210217 kernel signature: fa4a2fdc3e911fe8cd21bbb280a3c6fec5eb75f54301f33222005333d7d6cc4c all runs: OK # git bisect good 1ee43ba8d267b5e6729c45b8756263f69c2978cc Bisecting: 5 revisions left to test after this (roughly 3 steps) [e6cb007c45dedada0a847eaa486c49509d63b1e8] io_uring: zero ref_node after killing it testing commit e6cb007c45dedada0a847eaa486c49509d63b1e8 with gcc (GCC) 10.2.1 20210217 kernel signature: eea47e165e42bb4fdd9532f923b5c86402c9d0dc455092047c84a9e6a1358cc0 all runs: OK # git bisect good e6cb007c45dedada0a847eaa486c49509d63b1e8 Bisecting: 2 revisions left to test after this (roughly 2 steps) [ebf4a5db690a47e71056381ead8a134de7202694] io_uring: fix leaving invalid req->flags testing commit ebf4a5db690a47e71056381ead8a134de7202694 with gcc (GCC) 10.2.1 20210217 kernel signature: 7cef0bf515ce8a1a1501d91348207aba1db4b13d0fdfced0091214fbd7d627ad all runs: OK # git bisect good ebf4a5db690a47e71056381ead8a134de7202694 Bisecting: 0 revisions left to test after this (roughly 1 step) [27131549060ee87f1c50c56539b8f6c4c1a4acec] Merge branch 'for-5.12/io_uring' into io_uring-worker.v3 testing commit 27131549060ee87f1c50c56539b8f6c4c1a4acec with gcc (GCC) 10.2.1 20210217 kernel signature: 4ab7fb74d8847b220ed25ba8ef05cd8580df56795f67ad19207950c040f24ef7 all runs: OK # git bisect good 27131549060ee87f1c50c56539b8f6c4c1a4acec 7c25c0d16ef3c37e49c593ac92f69fa3884d4bb9 is the first bad commit commit 7c25c0d16ef3c37e49c593ac92f69fa3884d4bb9 Author: Jens Axboe Date: Tue Feb 16 07:17:00 2021 -0700 io_uring: remove the need for relying on an io-wq fallback worker We hit this case when the task is exiting, and we need somewhere to do background cleanup of requests. Instead of relying on the io-wq task manager to do this work for us, just stuff it somewhere where we can safely run it ourselves directly. Signed-off-by: Jens Axboe fs/io-wq.c | 12 ------------ fs/io-wq.h | 2 -- fs/io_uring.c | 37 ++++++++++++++++++++++++++++++++++--- 3 files changed, 34 insertions(+), 17 deletions(-) culprit signature: 1a2901351ff5ea1733acd7ab331e7560085cbdd629f031ea7df909dc2bd0e33b parent signature: 4ab7fb74d8847b220ed25ba8ef05cd8580df56795f67ad19207950c040f24ef7 Reproducer flagged being flaky revisions tested: 15, total time: 3h39m47.627194865s (build: 1h42m34.080969219s, test: 1h55m45.463534163s) first bad commit: 7c25c0d16ef3c37e49c593ac92f69fa3884d4bb9 io_uring: remove the need for relying on an io-wq fallback worker recipients (to): ["axboe@kernel.dk" "axboe@kernel.dk" "io-uring@vger.kernel.org"] recipients (cc): ["linux-fsdevel@vger.kernel.org" "linux-kernel@vger.kernel.org" "viro@zeniv.linux.org.uk"] crash: SYZFAIL: wrong response packet 2021/02/26 01:41:21 result: hanged=false err=executor 4: failed to write control pipe: write |1: broken pipe (errno 16: Device or resource busy) SYZFAIL: wrong response packet loop exited with status 67 2021/02/26 01:41:24 executed programs: 32 2021/02/26 01:41:29 executed programs: 215