INFO: task hung in vm_unmap_aliases

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: c10b57a5 Linux 4.14.176
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16cea8cfe00000
kernel config: https://syzkaller.appspot.com/x/.config?x=457897b554d08537
dashboard link: https://syzkaller.appspot.com/bug?extid=e156960b6c708348b482
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+e15696...@syzkaller.appspotmail.com

INFO: task syz-executor.0:19561 blocked for more than 140 seconds.
Not tainted 4.14.176-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0 D29168 19561 6338 0x80000004
Call Trace:
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
__mutex_lock_common kernel/locking/mutex.c:833 [inline]
__mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
vm_unmap_aliases mm/vmalloc.c:1123 [inline]
vm_unmap_aliases+0x314/0x3f0 mm/vmalloc.c:1088
change_page_attr_set_clr+0x543/0xa40 arch/x86/mm/pageattr.c:1472
change_page_attr_clear arch/x86/mm/pageattr.c:1532 [inline]
set_memory_ro+0x68/0x80 arch/x86/mm/pageattr.c:1761
bpf_jit_binary_lock_ro include/linux/filter.h:628 [inline]
bpf_int_jit_compile+0x441/0x5fe arch/x86/net/bpf_jit_comp.c:1192
bpf_prog_select_runtime+0xde/0x4f0 kernel/bpf/core.c:1455
bpf_prog_load+0x609/0xe00 kernel/bpf/syscall.c:1062
SYSC_bpf kernel/bpf/syscall.c:1512 [inline]
SyS_bpf+0xf89/0x2cd3 kernel/bpf/syscall.c:1477
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007feeae741c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00000000004da540 RCX: 000000000045c829
RDX: 0000000000000048 RSI: 0000000020000200 RDI: 0000000000000005
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000006a R14: 00000000004c30b4 R15: 00007feeae7426d4
INFO: task syz-executor.5:19575 blocked for more than 140 seconds.
Not tainted 4.14.176-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5 D29168 19575 6339 0x80000004
Call Trace:
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
__mutex_lock_common kernel/locking/mutex.c:833 [inline]
__mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
vm_unmap_aliases mm/vmalloc.c:1123 [inline]
vm_unmap_aliases+0x314/0x3f0 mm/vmalloc.c:1088
change_page_attr_set_clr+0x543/0xa40 arch/x86/mm/pageattr.c:1472


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.