bisecting fixing commit since 17a87580a8856170d59aab302226811a4ae69149 building syzkaller on b090c64363768b1fc574b98a8d42a3dd5f7af3e9 testing commit 17a87580a8856170d59aab302226811a4ae69149 with gcc (GCC) 8.1.0 kernel signature: c83cc671ed30e6199cd6c22c02ae8979bd0ca44a1e98246c06b4e58e45da574e run #0: crashed: WARNING in snd_info_get_line run #1: crashed: WARNING in snd_info_get_line run #2: crashed: WARNING in snd_info_get_line run #3: crashed: WARNING in snd_info_get_line run #4: crashed: WARNING in snd_info_get_line run #5: crashed: WARNING in snd_info_get_line run #6: crashed: WARNING in corrupted run #7: crashed: WARNING in snd_info_get_line run #8: crashed: WARNING in snd_info_get_line run #9: crashed: WARNING in snd_info_get_line testing current HEAD f6d5cb9e2c06f7d583dd9f4f7cca21d13d78c32a testing commit f6d5cb9e2c06f7d583dd9f4f7cca21d13d78c32a with gcc (GCC) 8.1.0 kernel signature: 88ccdf2bca54f94f0fcf12b4d575b0140643390e752fc7dec990e5720e5eab42 all runs: OK # git bisect start f6d5cb9e2c06f7d583dd9f4f7cca21d13d78c32a 17a87580a8856170d59aab302226811a4ae69149 Bisecting: 340 revisions left to test after this (roughly 8 steps) [719a92fae0434d11ee86d0f679663c14a2a13fc1] Revert "vxlan: fix tos value before xmit" testing commit 719a92fae0434d11ee86d0f679663c14a2a13fc1 with gcc (GCC) 8.1.0 kernel signature: 7679ff2577f9c1b23b478278db88e9fc28898bbf38dc20a9ba13107e2031db21 all runs: OK # git bisect bad 719a92fae0434d11ee86d0f679663c14a2a13fc1 Bisecting: 169 revisions left to test after this (roughly 7 steps) [8a330edef54f270c440034419f0694cee64c3075] ipvs: fix the connection sync failed in some cases testing commit 8a330edef54f270c440034419f0694cee64c3075 with gcc (GCC) 8.1.0 kernel signature: 5af1bbabe7bc73531efcf1c5cdb759cecb3f83ee5580e5b7c044db6f806163b3 all runs: OK # git bisect bad 8a330edef54f270c440034419f0694cee64c3075 Bisecting: 84 revisions left to test after this (roughly 6 steps) [5ca7b059ee4b099ecf56b5468cedfbba7e98b9e5] ALSA: line6: Perform sanity check for each URB creation testing commit 5ca7b059ee4b099ecf56b5468cedfbba7e98b9e5 with gcc (GCC) 8.1.0 kernel signature: 835f3f5fea0f40a80ea0556c046f0c681ad1ef2452850a0f732d31c5f6bccf91 all runs: crashed: WARNING in snd_info_get_line # git bisect good 5ca7b059ee4b099ecf56b5468cedfbba7e98b9e5 Bisecting: 42 revisions left to test after this (roughly 5 steps) [d2fc2e5774eb1911829ae761bc1569a05b72ebdc] sched: Fix unreliable rseq cpu_id for new tasks testing commit d2fc2e5774eb1911829ae761bc1569a05b72ebdc with gcc (GCC) 8.1.0 kernel signature: e19a2438904f097b44c0c4ded7e8a64c7f647fac214eca2199266ad72bd46847 run #0: crashed: WARNING in snd_info_get_line run #1: crashed: WARNING in snd_info_get_line run #2: crashed: WARNING in snd_info_get_line run #3: crashed: WARNING in snd_info_get_line run #4: crashed: WARNING in snd_info_get_line run #5: crashed: WARNING in corrupted run #6: crashed: WARNING in snd_info_get_line run #7: crashed: WARNING in snd_info_get_line run #8: crashed: WARNING in snd_info_get_line run #9: crashed: WARNING in snd_info_get_line # git bisect good d2fc2e5774eb1911829ae761bc1569a05b72ebdc Bisecting: 21 revisions left to test after this (roughly 5 steps) [c0c489e5430530a7021f4c889cd5931597e4b200] irqdomain/treewide: Keep firmware node unconditionally allocated testing commit c0c489e5430530a7021f4c889cd5931597e4b200 with gcc (GCC) 8.1.0 kernel signature: e290629f3a54cda6bc5aab9d7068c36973f98641d9a59440a322ba7c48fcb4a0 run #0: crashed: WARNING in snd_info_get_line run #1: crashed: WARNING in snd_info_get_line run #2: crashed: WARNING in snd_info_get_line run #3: crashed: WARNING in snd_info_get_line run #4: crashed: WARNING in snd_info_get_line run #5: crashed: WARNING in snd_info_get_line run #6: crashed: WARNING in snd_info_get_line run #7: crashed: WARNING in snd_info_get_line run #8: crashed: WARNING in corrupted run #9: crashed: WARNING in snd_info_get_line # git bisect good c0c489e5430530a7021f4c889cd5931597e4b200 Bisecting: 10 revisions left to test after this (roughly 4 steps) [060a740baf3a48002fa4a3249d05989eb519e5b8] bnxt_en: Fix race when modifying pause settings. testing commit 060a740baf3a48002fa4a3249d05989eb519e5b8 with gcc (GCC) 8.1.0 kernel signature: 1ad0ee40195523ac4f64d340f48eac8bcdbdb353d74facd4499a6f9a544652f1 all runs: OK # git bisect bad 060a740baf3a48002fa4a3249d05989eb519e5b8 Bisecting: 5 revisions left to test after this (roughly 3 steps) [2297df90b23b783ad3849a1301e22c1284d347dd] uprobes: Change handle_swbp() to send SIGTRAP with si_code=SI_KERNEL, to fix GDB regression testing commit 2297df90b23b783ad3849a1301e22c1284d347dd with gcc (GCC) 8.1.0 kernel signature: 3887b3134b9c63177cb6f5cef40f4160465bf9c7b6c9f16084505dddaab7769b run #0: crashed: WARNING in corrupted run #1: crashed: WARNING in snd_info_get_line run #2: crashed: WARNING in corrupted run #3: crashed: WARNING in corrupted run #4: crashed: WARNING in snd_info_get_line run #5: crashed: WARNING in corrupted run #6: crashed: WARNING in snd_info_get_line run #7: crashed: WARNING in snd_info_get_line run #8: crashed: WARNING in corrupted run #9: crashed: WARNING in corrupted # git bisect good 2297df90b23b783ad3849a1301e22c1284d347dd Bisecting: 2 revisions left to test after this (roughly 2 steps) [18a1602c2de19aa2d38b7932b7fc4cd15cb063bc] btrfs: fix double free on ulist after backref resolution failure testing commit 18a1602c2de19aa2d38b7932b7fc4cd15cb063bc with gcc (GCC) 8.1.0 kernel signature: 0a878e62cb612296c9cf67010b9564e1b1b6bf314d5b67fa14ddb355fcbb04f1 all runs: OK # git bisect bad 18a1602c2de19aa2d38b7932b7fc4cd15cb063bc Bisecting: 0 revisions left to test after this (roughly 1 step) [f4cbe15b501c504a19cce869c605c5e93f3e414e] ASoC: rt5670: Correct RT5670_LDO_SEL_MASK testing commit f4cbe15b501c504a19cce869c605c5e93f3e414e with gcc (GCC) 8.1.0 kernel signature: 0e9d52631ae6bb3e51465ce7dba413ab84d0a49700d0fdd8525370af8d7b787f all runs: OK # git bisect bad f4cbe15b501c504a19cce869c605c5e93f3e414e Bisecting: 0 revisions left to test after this (roughly 0 steps) [0c9d4b18bb8af4fa94e8db5fa4f465bdc2dbaddd] ALSA: info: Drop WARN_ON() from buffer NULL sanity check testing commit 0c9d4b18bb8af4fa94e8db5fa4f465bdc2dbaddd with gcc (GCC) 8.1.0 kernel signature: c06384d8b392b2c6be2be1b5db2a554c94f339bc692588b64f8fd031c7a7a771 all runs: OK # git bisect bad 0c9d4b18bb8af4fa94e8db5fa4f465bdc2dbaddd 0c9d4b18bb8af4fa94e8db5fa4f465bdc2dbaddd is the first bad commit commit 0c9d4b18bb8af4fa94e8db5fa4f465bdc2dbaddd Author: Takashi Iwai Date: Fri Jul 17 10:40:23 2020 +0200 ALSA: info: Drop WARN_ON() from buffer NULL sanity check commit 60379ba08532eca861e933b389526a4dc89e0c42 upstream. snd_info_get_line() has a sanity check of NULL buffer -- both buffer itself being NULL and buffer->buffer being NULL. Basically both checks are valid and necessary, but the problem is that it's with snd_BUG_ON() macro that triggers WARN_ON(). The latter condition (NULL buffer->buffer) can be met arbitrarily by user since the buffer is allocated at the first write, so it means that user can trigger WARN_ON() at will. This patch addresses it by simply moving buffer->buffer NULL check out of snd_BUG_ON() so that spurious WARNING is no longer triggered. Reported-by: syzbot+e42d0746c3c3699b6061@syzkaller.appspotmail.com Cc: Link: https://lore.kernel.org/r/20200717084023.5928-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman sound/core/info.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) culprit signature: c06384d8b392b2c6be2be1b5db2a554c94f339bc692588b64f8fd031c7a7a771 parent signature: 3887b3134b9c63177cb6f5cef40f4160465bf9c7b6c9f16084505dddaab7769b revisions tested: 12, total time: 3h26m3.354923401s (build: 2h0m42.018277937s, test: 1h23m21.128458359s) first good commit: 0c9d4b18bb8af4fa94e8db5fa4f465bdc2dbaddd ALSA: info: Drop WARN_ON() from buffer NULL sanity check recipients (to): ["alsa-devel@alsa-project.org" "gregkh@linuxfoundation.org" "perex@perex.cz" "tiwai@suse.com" "tiwai@suse.de"] recipients (cc): ["gregkh@linuxfoundation.org" "linux-kernel@vger.kernel.org"]