bisecting fixing commit since 357668399cf70ccdc0ee8967bff3448d0f4f9ae1 building syzkaller on 4d1ab643be2091f794ec55d83ec8acf7b0a60be3 testing commit 357668399cf70ccdc0ee8967bff3448d0f4f9ae1 with gcc (GCC) 8.1.0 kernel signature: 7f5dc4e1b15a7bd0c1d35afef3638a1460c81dd98b3b4ef0f8b23410ac2eda90 all runs: crashed: general protection fault in padata_reorder testing current HEAD 5692097116094a4a7045abcc1dbc172dbdc5657e testing commit 5692097116094a4a7045abcc1dbc172dbdc5657e with gcc (GCC) 8.1.0 kernel signature: e99f1bbe07e9302ac3e0566f86a61b49c8f69d54cfbc5e26b73d955696465220 all runs: OK # git bisect start 5692097116094a4a7045abcc1dbc172dbdc5657e 357668399cf70ccdc0ee8967bff3448d0f4f9ae1 Bisecting: 273 revisions left to test after this (roughly 8 steps) [47f44085e01f7f68450d7a1a46369a6252505223] NFS: Fix memory leaks testing commit 47f44085e01f7f68450d7a1a46369a6252505223 with gcc (GCC) 8.1.0 kernel signature: 86cd1016fd4a657679878d25df9a0b3c44102dd71ca2427ca1f4775d21cd9110 all runs: OK # git bisect bad 47f44085e01f7f68450d7a1a46369a6252505223 Bisecting: 136 revisions left to test after this (roughly 7 steps) [d5e7ba4ec90f2aaa7ea87a13d47eb60e4702e46d] ext4, jbd2: ensure panic when aborting with zero errno testing commit d5e7ba4ec90f2aaa7ea87a13d47eb60e4702e46d with gcc (GCC) 8.1.0 kernel signature: fcfe9ccfe8c62d708fbdf77ef9f9a1286a17b2d667293994cd05a8a768afe824 all runs: OK # git bisect bad d5e7ba4ec90f2aaa7ea87a13d47eb60e4702e46d Bisecting: 67 revisions left to test after this (roughly 6 steps) [bda71c14e115dbdff20136930ac289fed9ef3767] ext4: fix checksum errors with indexed dirs testing commit bda71c14e115dbdff20136930ac289fed9ef3767 with gcc (GCC) 8.1.0 kernel signature: 276c747007aa2a3f24b38145dd257aebb27cf44ba5b678c5b08b564aaa8afd79 all runs: OK # git bisect bad bda71c14e115dbdff20136930ac289fed9ef3767 Bisecting: 33 revisions left to test after this (roughly 5 steps) [12e2dca1f224fde0ec1dec10a3c6e178c6dd8a7a] arm64: cpufeature: Fix the type of no FP/SIMD capability testing commit 12e2dca1f224fde0ec1dec10a3c6e178c6dd8a7a with gcc (GCC) 8.1.0 kernel signature: 2453efb719dc1d80d262948183209372320d6efe095002e9aca55100ef51a72e all runs: crashed: general protection fault in padata_reorder # git bisect good 12e2dca1f224fde0ec1dec10a3c6e178c6dd8a7a Bisecting: 16 revisions left to test after this (roughly 4 steps) [510cd44619e873098283e0093bacfba1d7401160] x86/stackframe: Move ENCODE_FRAME_POINTER to asm/frame.h testing commit 510cd44619e873098283e0093bacfba1d7401160 with gcc (GCC) 8.1.0 kernel signature: e87321bbac7dd13aa61554b481aa70ee34a56632a3896c47cd83f62fbda680f7 all runs: crashed: general protection fault in padata_reorder # git bisect good 510cd44619e873098283e0093bacfba1d7401160 Bisecting: 8 revisions left to test after this (roughly 3 steps) [f09e9a45d12fca8e5dde018784edf70ef1c7d2aa] ALSA: usb-audio: Fix UAC2/3 effect unit parsing testing commit f09e9a45d12fca8e5dde018784edf70ef1c7d2aa with gcc (GCC) 8.1.0 kernel signature: e329844a55d55eb0606255fcac846a344346458f3f5ba0cc5cab2b9a5e4dbce0 all runs: OK # git bisect bad f09e9a45d12fca8e5dde018784edf70ef1c7d2aa Bisecting: 3 revisions left to test after this (roughly 2 steps) [9b15f7fae677336e04b9e026ff91854e43165455] Linux 4.19.104 testing commit 9b15f7fae677336e04b9e026ff91854e43165455 with gcc (GCC) 8.1.0 kernel signature: 7db4a3c1b9d2a9e069803d21b4dc52d1fd564a28cbd9af47053e05accb2e7354 all runs: OK # git bisect bad 9b15f7fae677336e04b9e026ff91854e43165455 Bisecting: 1 revision left to test after this (roughly 1 step) [77bad0ab1b725e6c348277fcdb8790908286ca20] serial: uartps: Move the spinlock after the read of the tx empty testing commit 77bad0ab1b725e6c348277fcdb8790908286ca20 with gcc (GCC) 8.1.0 kernel signature: 0971fb71deb6a17b0906c2be5deb3aadd9322ebc4f4e5c0b14304234007ff48f all runs: crashed: general protection fault in padata_reorder # git bisect good 77bad0ab1b725e6c348277fcdb8790908286ca20 Bisecting: 0 revisions left to test after this (roughly 0 steps) [cad926f70b5a3ac61de0274c28891dc7fbd8d2ad] padata: fix null pointer deref of pd->pinst testing commit cad926f70b5a3ac61de0274c28891dc7fbd8d2ad with gcc (GCC) 8.1.0 kernel signature: d6a4df4f9970b4a22586b2f9e942305e01cd015de7c77c1319c4944d4ab15f53 all runs: OK # git bisect bad cad926f70b5a3ac61de0274c28891dc7fbd8d2ad cad926f70b5a3ac61de0274c28891dc7fbd8d2ad is the first bad commit commit cad926f70b5a3ac61de0274c28891dc7fbd8d2ad Author: Daniel Jordan Date: Fri Feb 14 13:28:21 2020 -0500 padata: fix null pointer deref of pd->pinst The 4.19 backport dc34710a7aba ("padata: Remove broken queue flushing") removed padata_alloc_pd()'s assignment to pd->pinst, resulting in: Unable to handle kernel NULL pointer dereference ... ... pc : padata_reorder+0x144/0x2e0 ... Call trace: padata_reorder+0x144/0x2e0 padata_do_serial+0xc8/0x128 pcrypt_aead_enc+0x60/0x70 [pcrypt] padata_parallel_worker+0xd8/0x138 process_one_work+0x1bc/0x4b8 worker_thread+0x164/0x580 kthread+0x134/0x138 ret_from_fork+0x10/0x18 This happened because the backport was based on an enhancement that moved this assignment but isn't in 4.19: bfde23ce200e ("padata: unbind parallel jobs from specific CPUs") Simply restore the assignment to fix the crash. Fixes: dc34710a7aba ("padata: Remove broken queue flushing") Reported-by: Yang Yingliang Signed-off-by: Daniel Jordan Cc: Greg Kroah-Hartman Cc: Herbert Xu Cc: Sasha Levin Cc: Steffen Klassert Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman kernel/padata.c | 1 + 1 file changed, 1 insertion(+) culprit signature: d6a4df4f9970b4a22586b2f9e942305e01cd015de7c77c1319c4944d4ab15f53 parent signature: 0971fb71deb6a17b0906c2be5deb3aadd9322ebc4f4e5c0b14304234007ff48f revisions tested: 11, total time: 3h31m51.451829929s (build: 1h58m42.693013931s, test: 1h30m36.691430143s) first good commit: cad926f70b5a3ac61de0274c28891dc7fbd8d2ad padata: fix null pointer deref of pd->pinst cc: ["daniel.m.jordan@oracle.com" "gregkh@linuxfoundation.org" "linux-crypto@vger.kernel.org" "linux-kernel@vger.kernel.org" "steffen.klassert@secunet.com"]