bisecting fixing commit since f6e27dbb1afabcba436e346d6aa88a592a1436bb building syzkaller on d8074e0bb985b9be6611e16b45b8657f20157a4b testing commit f6e27dbb1afabcba436e346d6aa88a592a1436bb with gcc (GCC) 8.1.0 kernel signature: b80bbc881936760001d7d00ea6aa70c3d1680a96 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in tc_bind_tclass testing current HEAD a844dc4c544291470aa69edbe2434b040794e269 testing commit a844dc4c544291470aa69edbe2434b040794e269 with gcc (GCC) 8.1.0 kernel signature: 7a68b737bc432ec8283c8cb14fb871d6d1eddc62 all runs: OK # git bisect start a844dc4c544291470aa69edbe2434b040794e269 f6e27dbb1afabcba436e346d6aa88a592a1436bb Bisecting: 795 revisions left to test after this (roughly 10 steps) [a4f14d5a0795fe7c4f75d31ef4abf816570e3872] x86/speculation/taa: Add documentation for TSX Async Abort testing commit a4f14d5a0795fe7c4f75d31ef4abf816570e3872 with gcc (GCC) 8.1.0 kernel signature: 384dafed637181807cc05a1b78455e01838a026c all runs: OK # git bisect bad a4f14d5a0795fe7c4f75d31ef4abf816570e3872 Bisecting: 397 revisions left to test after this (roughly 9 steps) [2e18e22063986658f0ebfb90f742ab1f6e378f33] Revert "drm/radeon: Fix EEH during kexec" testing commit 2e18e22063986658f0ebfb90f742ab1f6e378f33 with gcc (GCC) 8.1.0 kernel signature: c63a9fabd7281e36d665459e22f1c01c86267b10 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in tc_bind_tclass # git bisect good 2e18e22063986658f0ebfb90f742ab1f6e378f33 Bisecting: 198 revisions left to test after this (roughly 8 steps) [80d0c02e28601ba0631d6dd92b93d16fda76832c] arm64: dts: Fix gpio to pinmux mapping testing commit 80d0c02e28601ba0631d6dd92b93d16fda76832c with gcc (GCC) 8.1.0 kernel signature: 931e8d7dcf68180052d40667a017ab75370a46d9 all runs: OK # git bisect bad 80d0c02e28601ba0631d6dd92b93d16fda76832c Bisecting: 99 revisions left to test after this (roughly 7 steps) [b425d011e83d220d3be0a19561d6b33d11358fa5] kvm: vmx: Basic APIC virtualization controls have three settings testing commit b425d011e83d220d3be0a19561d6b33d11358fa5 with gcc (GCC) 8.1.0 kernel signature: 80e711a7bfb3f4a9dffc1ea661da5e243b6e4fdf all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in tc_bind_tclass # git bisect good b425d011e83d220d3be0a19561d6b33d11358fa5 Bisecting: 49 revisions left to test after this (roughly 6 steps) [22731e226b8f47fd4843673ed68d5e7c43c48ebc] fs: ocfs2: fix a possible null-pointer dereference in ocfs2_info_scan_inode_alloc() testing commit 22731e226b8f47fd4843673ed68d5e7c43c48ebc with gcc (GCC) 8.1.0 kernel signature: c0a19f91721c0f6621fde748d5a744901ea4adbc all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in tc_bind_tclass # git bisect good 22731e226b8f47fd4843673ed68d5e7c43c48ebc Bisecting: 24 revisions left to test after this (roughly 5 steps) [294da39e05db61cbad1f3367de15176215fdf422] USB: serial: whiteheat: fix line-speed endianness testing commit 294da39e05db61cbad1f3367de15176215fdf422 with gcc (GCC) 8.1.0 kernel signature: 9bc62451b1137e8295b989417b2c0a92ea62325f all runs: OK # git bisect bad 294da39e05db61cbad1f3367de15176215fdf422 Bisecting: 12 revisions left to test after this (roughly 4 steps) [56ab84408da105d46aa565e9221bf9926e814b91] thunderbolt: Use 32-bit writes when writing ring producer/consumer testing commit 56ab84408da105d46aa565e9221bf9926e814b91 with gcc (GCC) 8.1.0 kernel signature: e39b979fdf14f357186c6ea79f04d74b378dfbea all runs: OK # git bisect bad 56ab84408da105d46aa565e9221bf9926e814b91 Bisecting: 5 revisions left to test after this (roughly 3 steps) [640fb32d61f32d1011bf9a96805e5a8d033abcea] NFSv4: Fix leak of clp->cl_acceptor string testing commit 640fb32d61f32d1011bf9a96805e5a8d033abcea with gcc (GCC) 8.1.0 kernel signature: f1140c91cd1ef83872f7236dc74098a684b311f0 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in tc_bind_tclass # git bisect good 640fb32d61f32d1011bf9a96805e5a8d033abcea Bisecting: 2 revisions left to test after this (roughly 2 steps) [4df728651b8a99693c69962d8e5a5b9e5a3bbcc7] nbd: verify socket is supported during setup testing commit 4df728651b8a99693c69962d8e5a5b9e5a3bbcc7 with gcc (GCC) 8.1.0 kernel signature: fb4232cb07fd3623f6e1a7b829181502acd3885f all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in tc_bind_tclass # git bisect good 4df728651b8a99693c69962d8e5a5b9e5a3bbcc7 Bisecting: 0 revisions left to test after this (roughly 1 step) [54b9f5791846d2de59e8c65502b3f1071f65424f] net_sched: check cops->tcf_block in tc_bind_tclass() testing commit 54b9f5791846d2de59e8c65502b3f1071f65424f with gcc (GCC) 8.1.0 kernel signature: b4f864fd71c98cef0833361b53bd0269d7b90bcd all runs: OK # git bisect bad 54b9f5791846d2de59e8c65502b3f1071f65424f Bisecting: 0 revisions left to test after this (roughly 0 steps) [d7030f05a84cf6ce9587dce5fab9774666597cd5] USB: legousbtower: fix a signedness bug in tower_probe() testing commit d7030f05a84cf6ce9587dce5fab9774666597cd5 with gcc (GCC) 8.1.0 kernel signature: d002e907fdfabbbfa48a0c0695f5a8679bfda8a5 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in tc_bind_tclass # git bisect good d7030f05a84cf6ce9587dce5fab9774666597cd5 54b9f5791846d2de59e8c65502b3f1071f65424f is the first bad commit commit 54b9f5791846d2de59e8c65502b3f1071f65424f Author: Cong Wang Date: Thu Oct 31 11:42:59 2019 -0700 net_sched: check cops->tcf_block in tc_bind_tclass() commit 8b142a00edcf8422ca48b8de88d286efb500cb53 upstream At least sch_red and sch_tbf don't implement ->tcf_block() while still have a non-zero tc "class". Instead of adding nop implementations to each of such qdisc's, we can just relax the check of cops->tcf_block() in tc_bind_tclass(). They don't support TC filter anyway. Reported-by: syzbot+21b29db13c065852f64b@syzkaller.appspotmail.com Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Zubin Mithra Signed-off-by: Sasha Levin net/sched/sch_api.c | 2 ++ 1 file changed, 2 insertions(+) culprit signature: b4f864fd71c98cef0833361b53bd0269d7b90bcd parent signature: d002e907fdfabbbfa48a0c0695f5a8679bfda8a5 revisions tested: 13, total time: 3h6m39.391693711s (build: 1h42m55.603387575s, test: 1h22m33.244183247s) first good commit: 54b9f5791846d2de59e8c65502b3f1071f65424f net_sched: check cops->tcf_block in tc_bind_tclass() cc: ["davem@davemloft.net" "sashal@kernel.org" "xiyou.wangcong@gmail.com" "zsm@chromium.org"]