bisecting fixing commit since 59126901f200f5fc907153468b03c64e0081b6e6 building syzkaller on abf9ba4fc75d9b29af15625d44dcfc1360fad3b7 testing commit 59126901f200f5fc907153468b03c64e0081b6e6 with gcc (GCC) 8.1.0 kernel signature: f2e52fdc79835c7e2900bd124219386ddb3c9499306405c00a6ba0652d5cc140 run #0: crashed: stack segment fault in dump_schedule run #1: crashed: BUG: sleeping function called from invalid context in exc_page_fault run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK testing current HEAD 4429f14aeea979b63bcafdcf9f09677fcf8fd475 testing commit 4429f14aeea979b63bcafdcf9f09677fcf8fd475 with gcc (GCC) 8.1.0 kernel signature: 084c5a0e1ed6dedb24218c1fcf5a0df079e39d18d1412e6d99ebdacd6d2f27f8 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: crashed: BUG: sleeping function called from invalid context in exc_page_fault run #4: OK run #5: OK run #6: OK run #7: crashed: BUG: sleeping function called from invalid context in exc_page_fault run #8: OK run #9: OK revisions tested: 2, total time: 30m35.969083701s (build: 9m14.461002871s, test: 20m52.952391257s) the crash still happens on HEAD commit msg: Merge tag 'block-5.10-2020-11-07' 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: 4669, name: syz-executor832 4 locks held by syz-executor832/4669: #0: ffff88810977cc68 (&pipe->mutex/1){+.+.}-{3:3}, at: splice_from_pipe+0x4a/0x90 fs/splice.c:596 #1: ffffffff84625e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #1: ffffffff84625e48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x14a/0x480 net/core/rtnetlink.c:5559 #2: ffffffff843d8940 (rcu_read_lock){....}-{1:2}, at: taprio_dump+0x0/0x4a0 net/sched/sch_taprio.c:439 #3: ffff88810b576e28 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:56 [inline] #3: ffff88810b576e28 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1313 [inline] #3: ffff88810b576e28 (&mm->mmap_lock#2){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1429 [inline] #3: ffff88810b576e28 (&mm->mmap_lock#2){++++}-{3:3}, at: exc_page_fault+0x156/0x700 arch/x86/mm/fault.c:1485 Preemption disabled at: [<0000000000000000>] 0x0 CPU: 0 PID: 4669 Comm: syz-executor832 Not tainted 5.10.0-rc2-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+0xa3/0xc8 lib/dump_stack.c:118 ___might_sleep.cold.112+0xfb/0x10f kernel/sched/core.c:7298 do_user_addr_fault arch/x86/mm/fault.c:1330 [inline] handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x171/0x700 arch/x86/mm/fault.c:1485 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:583 RIP: 0010:nla_put_u32 include/net/netlink.h:1309 [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:ffffc9000206b808 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88810d357100 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881147610c0 RBP: 0000000000000000 R08: 0000000000000004 R09: ffff8881147610c0 R10: 0000000000000e14 R11: 0000000000000001 R12: ffff8881147610bc R13: ffff88811d8dbb90 R14: ffff8881147610b8 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.29+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:5562 netlink_rcv_skb+0x49/0xf0 net/netlink/af_netlink.c:2494 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:2833 kernel_sendpage+0x5c/0xf0 net/socket.c:3646 sock_sendpage+0x1e/0x30 net/socket.c:944 pipe_to_sendpage+0x5b/0xa0 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0xb1/0x1a0 fs/splice.c:562 splice_from_pipe+0x58/0x90 fs/splice.c:597 do_splice_from fs/splice.c:764 [inline] do_splice+0x306/0x620 fs/splice.c:1059 __do_splice+0xd5/0x160 fs/splice.c:1137 __do_sys_splice fs/splice.c:1343 [inline] __se_sys_splice fs/splice.c:1325 [inline] __x64_sys_splice+0x8d/0x100 fs/splice.c:1325 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x44a4f9 Code: e8 ac e7 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 cb 05 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe461e1ad88 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00000000006e6a08 RCX: 000000000044a4f9 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00000000006e6a00 R08: 0000000000010973 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006e6a0c R13: 140b0024000000a4 R14: 0000000000000000 R15: 000000306d616574 BUG: kernel NULL pointer dereference, address: 0000000000000024 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 10c9a7067 P4D 10c9a7067 PUD 11e2e5067 PMD 0 Oops: 0000 [#1] PREEMPT SMP CPU: 0 PID: 4669 Comm: syz-executor832 Tainted: G W 5.10.0-rc2-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:1309 [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:ffffc9000206b808 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88810d357100 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881147610c0 RBP: 0000000000000000 R08: 0000000000000004 R09: ffff8881147610c0 R10: 0000000000000e14 R11: 0000000000000001 R12: ffff8881147610bc R13: ffff88811d8dbb90 R14: ffff8881147610b8 R15: 0000000000000000 FS: 00007fe461e1b700(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000010ca55000 CR4: 00000000001506f0 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.29+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:5562 netlink_rcv_skb+0x49/0xf0 net/netlink/af_netlink.c:2494 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:2833 kernel_sendpage+0x5c/0xf0 net/socket.c:3646 sock_sendpage+0x1e/0x30 net/socket.c:944 pipe_to_sendpage+0x5b/0xa0 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0xb1/0x1a0 fs/splice.c:562 splice_from_pipe+0x58/0x90 fs/splice.c:597 do_splice_from fs/splice.c:764 [inline] do_splice+0x306/0x620 fs/splice.c:1059 __do_splice+0xd5/0x160 fs/splice.c:1137 __do_sys_splice fs/splice.c:1343 [inline] __se_sys_splice fs/splice.c:1325 [inline] __x64_sys_splice+0x8d/0x100 fs/splice.c:1325 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x44a4f9 Code: e8 ac e7 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 cb 05 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe461e1ad88 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00000000006e6a08 RCX: 000000000044a4f9 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00000000006e6a00 R08: 0000000000010973 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006e6a0c R13: 140b0024000000a4 R14: 0000000000000000 R15: 000000306d616574 Modules linked in: CR2: 0000000000000024 ---[ end trace 40a5d6eb304c696f ]--- RIP: 0010:nla_put_u32 include/net/netlink.h:1309 [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:ffffc9000206b808 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88810d357100 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881147610c0 RBP: 0000000000000000 R08: 0000000000000004 R09: ffff8881147610c0 R10: 0000000000000e14 R11: 0000000000000001 R12: ffff8881147610bc R13: ffff88811d8dbb90 R14: ffff8881147610b8 R15: 0000000000000000 FS: 00007fe461e1b700(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe13f94f000 CR3: 000000010ca55000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400