WARNING in sigsuspend

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 62872f95 Merge 4.4.174 into android-4.4
git tree: android-4.4
console output: https://syzkaller.appspot.com/x/log.txt?x=17181107200000
kernel config: https://syzkaller.appspot.com/x/.config?x=47bc4dd423780c4a
dashboard link: https://syzkaller.appspot.com/bug?extid=07727c4be0ba2484f546
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=163ec73b200000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17214e7d200000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+07727c...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 2273 at ./arch/x86/include/asm/thread_info.h:273
set_restore_sigmask arch/x86/include/asm/thread_info.h:273 [inline]()
WARNING: CPU: 0 PID: 2273 at ./arch/x86/include/asm/thread_info.h:273
sigsuspend kernel/signal.c:3534 [inline]()
WARNING: CPU: 0 PID: 2273 at ./arch/x86/include/asm/thread_info.h:273
sigsuspend+0x18d/0x1f0 kernel/signal.c:3527()
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 2273 Comm: syz-executor923 Not tainted 4.4.174+ #4
0000000000000000 368e7cdbe52a363d ffff8800b2bafd60 ffffffff81aad1a1
0000000000000000 ffffffff82835ee0 ffffffff8283c0e0 0000000000000111
ffffffff811027fd ffff8800b2bafe40 ffffffff813a48c2 0000000041b58ab3
Call Trace:
[<ffffffff81aad1a1>] __dump_stack lib/dump_stack.c:15 [inline]
[<ffffffff81aad1a1>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
[<ffffffff813a48c2>] panic+0x1b9/0x37b kernel/panic.c:112
[<ffffffff813a4ab9>] warn_slowpath_common kernel/panic.c:455 [inline]
[<ffffffff813a4ab9>] warn_slowpath_common.cold+0x20/0x20 kernel/panic.c:435
[<ffffffff810d3aaa>] warn_slowpath_null+0x2a/0x30 kernel/panic.c:492
[<ffffffff811027fd>] set_restore_sigmask
arch/x86/include/asm/thread_info.h:273 [inline]
[<ffffffff811027fd>] sigsuspend kernel/signal.c:3534 [inline]
[<ffffffff811027fd>] sigsuspend+0x18d/0x1f0 kernel/signal.c:3527
[<ffffffff81106d91>] SYSC_rt_sigsuspend kernel/signal.c:3554 [inline]
[<ffffffff81106d91>] SyS_rt_sigsuspend+0xa1/0xf0 kernel/signal.c:3544
[<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
Kernel Offset: disabled
Rebooting in 86400 seconds..


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