bisecting fixing commit since 59126901f200f5fc907153468b03c64e0081b6e6 building syzkaller on abf9ba4fc75d9b29af15625d44dcfc1360fad3b7 testing commit 59126901f200f5fc907153468b03c64e0081b6e6 with gcc (GCC) 8.1.0 kernel signature: ceb3c9deaabb80faaf3d75331609fbb3c127e0ba1b86ee49c9a577821034cbab run #0: crashed: BUG: sleeping function called from invalid context in exc_page_fault run #1: crashed: BUG: sleeping function called from invalid context in exc_page_fault run #2: crashed: BUG: sleeping function called from invalid context in exc_page_fault run #3: crashed: WARNING: ODEBUG bug in taprio_change run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK testing current HEAD 583090b1b8232e6eae243a9009699666153a13a9 testing commit 583090b1b8232e6eae243a9009699666153a13a9 with gcc (GCC) 8.1.0 kernel signature: fbf04d31c8996b720a7a8a53ba6f64cd128ea00e657150e2f90896afba98c6fa run #0: crashed: BUG: sleeping function called from invalid context in exc_page_fault run #1: crashed: stack segment fault in dump_schedule run #2: crashed: BUG: sleeping function called from invalid context in exc_page_fault run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK revisions tested: 2, total time: 31m44.162683878s (build: 9m53.676089062s, test: 21m26.515973903s) the crash still happens on HEAD commit msg: Merge tag 'block5.9-2020-10-08' of git://git.kernel.dk/linux-block crash: BUG: sleeping function called from invalid context in exc_page_fault BUG: sleeping function called from invalid context at arch/x86/mm/fault.c:1330 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 30483, name: syz-executor.2 4 locks held by syz-executor.2/30483: #0: ffff88810f0e7268 (&pipe->mutex/1){+.+.}-{3:3}, at: splice_from_pipe+0x4a/0x90 fs/splice.c:680 #1: ffffffff84534008 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #1: ffffffff84534008 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x14a/0x480 net/core/rtnetlink.c:5560 #2: ffffffff842f5dc0 (rcu_read_lock){....}-{1:2}, at: taprio_dump+0x0/0x4a0 net/sched/sch_taprio.c:439 #3: ffff88810f8c67e8 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:56 [inline] #3: ffff88810f8c67e8 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1313 [inline] #3: ffff88810f8c67e8 (&mm->mmap_lock#2){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1429 [inline] #3: ffff88810f8c67e8 (&mm->mmap_lock#2){++++}-{3:3}, at: exc_page_fault+0x156/0x720 arch/x86/mm/fault.c:1482 Preemption disabled at: [<0000000000000000>] 0x0 CPU: 0 PID: 30483 Comm: syz-executor.2 Not tainted 5.9.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xa3/0xcc lib/dump_stack.c:118 ___might_sleep.cold.112+0xfb/0x10f kernel/sched/core.c:7299 do_user_addr_fault arch/x86/mm/fault.c:1330 [inline] handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x171/0x720 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:538 RIP: 0010:nla_put_u32 include/net/netlink.h:1294 [inline] RIP: 0010:dump_entry net/sched/sch_taprio.c:1743 [inline] RIP: 0010:dump_schedule+0xf4/0x260 net/sched/sch_taprio.c:1788 Code: 01 00 00 85 c0 0f 88 16 01 00 00 49 8b 6d 10 49 83 c5 10 49 39 ed 0f 85 c4 00 00 00 e9 44 01 00 00 4d 85 e4 0f 84 dd 00 00 00 <8b> 45 24 48 89 e1 ba 04 00 00 00 be 01 00 00 00 48 89 df 89 04 24 RSP: 0018:ffffc9000592f878 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff888121977400 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88810e44d0c0 RBP: 0000000000000000 R08: 0000000000000004 R09: ffff88810e44d0c0 R10: 0000000000000e14 R11: 3a8c003605f79ec7 R12: ffff88810e44d0bc R13: ffff88810e45fb10 R14: ffff88810e44d0b8 R15: 0000000000000000 taprio_dump+0x1e2/0x4a0 net/sched/sch_taprio.c:1839 tc_fill_qdisc+0x149/0x490 net/sched/sch_api.c:916 qdisc_notify.isra.34+0x105/0x120 net/sched/sch_api.c:983 tc_modify_qdisc+0x39c/0x810 net/sched/sch_api.c:1635 rtnetlink_rcv_msg+0x173/0x480 net/core/rtnetlink.c:5563 netlink_rcv_skb+0x41/0x110 net/netlink/af_netlink.c:2470 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x19a/0x270 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x248/0x480 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0x2b/0x40 net/socket.c:671 sock_no_sendpage+0x94/0xc0 net/core/sock.c:2852 kernel_sendpage+0x5c/0xf0 net/socket.c:3644 sock_sendpage+0x1e/0x30 net/socket.c:944 pipe_to_sendpage+0x5b/0xa0 fs/splice.c:448 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0xb1/0x1a0 fs/splice.c:646 splice_from_pipe+0x58/0x90 fs/splice.c:681 do_splice+0x30c/0x660 fs/splice.c:1164 __do_sys_splice fs/splice.c:1439 [inline] __se_sys_splice fs/splice.c:1421 [inline] __x64_sys_splice+0x8d/0x100 fs/splice.c:1421 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d5b9 Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f73a80aac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000033980 RCX: 000000000045d5b9 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000118cf98 R08: 0000000000010973 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffca169157f R14: 00007f73a80ab9c0 R15: 000000000118cf4c BUG: kernel NULL pointer dereference, address: 0000000000000024 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 10f34b067 P4D 10f34b067 PUD 10f281067 PMD 0 Oops: 0000 [#1] PREEMPT SMP CPU: 1 PID: 30483 Comm: syz-executor.2 Tainted: G W 5.9.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:nla_put_u32 include/net/netlink.h:1294 [inline] RIP: 0010:dump_entry net/sched/sch_taprio.c:1743 [inline] RIP: 0010:dump_schedule+0xf4/0x260 net/sched/sch_taprio.c:1788 Code: 01 00 00 85 c0 0f 88 16 01 00 00 49 8b 6d 10 49 83 c5 10 49 39 ed 0f 85 c4 00 00 00 e9 44 01 00 00 4d 85 e4 0f 84 dd 00 00 00 <8b> 45 24 48 89 e1 ba 04 00 00 00 be 01 00 00 00 48 89 df 89 04 24 RSP: 0018:ffffc9000592f878 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff888121977400 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88810e44d0c0 RBP: 0000000000000000 R08: 0000000000000004 R09: ffff88810e44d0c0 R10: 0000000000000e14 R11: 3a8c003605f79ec7 R12: ffff88810e44d0bc R13: ffff88810e45fb10 R14: ffff88810e44d0b8 R15: 0000000000000000 FS: 00007f73a80ab700(0000) GS:ffff88812c100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3b60246000 CR3: 000000010f249000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: taprio_dump+0x1e2/0x4a0 net/sched/sch_taprio.c:1839 tc_fill_qdisc+0x149/0x490 net/sched/sch_api.c:916 qdisc_notify.isra.34+0x105/0x120 net/sched/sch_api.c:983 tc_modify_qdisc+0x39c/0x810 net/sched/sch_api.c:1635 rtnetlink_rcv_msg+0x173/0x480 net/core/rtnetlink.c:5563 netlink_rcv_skb+0x41/0x110 net/netlink/af_netlink.c:2470 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x19a/0x270 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x248/0x480 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0x2b/0x40 net/socket.c:671 sock_no_sendpage+0x94/0xc0 net/core/sock.c:2852 kernel_sendpage+0x5c/0xf0 net/socket.c:3644 sock_sendpage+0x1e/0x30 net/socket.c:944 pipe_to_sendpage+0x5b/0xa0 fs/splice.c:448 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0xb1/0x1a0 fs/splice.c:646 splice_from_pipe+0x58/0x90 fs/splice.c:681 do_splice+0x30c/0x660 fs/splice.c:1164 __do_sys_splice fs/splice.c:1439 [inline] __se_sys_splice fs/splice.c:1421 [inline] __x64_sys_splice+0x8d/0x100 fs/splice.c:1421 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d5b9 Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f73a80aac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000033980 RCX: 000000000045d5b9 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000118cf98 R08: 0000000000010973 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffca169157f R14: 00007f73a80ab9c0 R15: 000000000118cf4c Modules linked in: CR2: 0000000000000024 ---[ end trace f617970951a1aae9 ]--- RIP: 0010:nla_put_u32 include/net/netlink.h:1294 [inline] RIP: 0010:dump_entry net/sched/sch_taprio.c:1743 [inline] RIP: 0010:dump_schedule+0xf4/0x260 net/sched/sch_taprio.c:1788 Code: 01 00 00 85 c0 0f 88 16 01 00 00 49 8b 6d 10 49 83 c5 10 49 39 ed 0f 85 c4 00 00 00 e9 44 01 00 00 4d 85 e4 0f 84 dd 00 00 00 <8b> 45 24 48 89 e1 ba 04 00 00 00 be 01 00 00 00 48 89 df 89 04 24 RSP: 0018:ffffc9000592f878 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff888121977400 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88810e44d0c0 RBP: 0000000000000000 R08: 0000000000000004 R09: ffff88810e44d0c0 R10: 0000000000000e14 R11: 3a8c003605f79ec7 R12: ffff88810e44d0bc R13: ffff88810e45fb10 R14: ffff88810e44d0b8 R15: 0000000000000000 FS: 00007f73a80ab700(0000) GS:ffff88812c100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3b6024d028 CR3: 000000010f249000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400