[syzbot] BUG: unable to handle kernel paging request in timerqueue_del

From: syzbot
Date: Mon Sep 06 2021 - 06:28:32 EST


Hello,

syzbot found the following issue on:

HEAD commit: b91db6a0b52e Merge tag 'for-5.15/io_uring-vfs-2021-08-30' ..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12a993fe300000
kernel config: https://syzkaller.appspot.com/x/.config?x=210537ff2ddcc232
dashboard link: https://syzkaller.appspot.com/bug?extid=89ee54915f0135ac38e0
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
userspace arch: i386

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+89ee54915f0135ac38e0@xxxxxxxxxxxxxxxxxxxxxxxxx

BUG: unable to handle page fault for address: ffffc9001bdbfd88
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 10800067 P4D 10800067 PUD 109ba067 PMD 136067 PTE 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 19707 Comm: syz-executor.1 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:173 [inline]
RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:216 [inline]
RIP: 0010:rb_erase+0x5f6/0x1210 lib/rbtree.c:443
Code: e3 fc 0f 84 0c 01 00 00 48 8d 7b 10 48 89 dd 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 84 0a 00 00 <4c> 3b 6b 10 0f 84 37 02 00 00 48 8d 7b 08 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc90000007d88 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: ffffc9001bdbfd78 RCX: 0000000000000000
RDX: 1ffff920037b7fb1 RSI: ffff8880b9c424d0 RDI: ffffc9001bdbfd88
RBP: ffffc9001bdbfd78 R08: ffffc9001bdbfd79 R09: 0000000000000001
R10: ffffffff83f38fdc R11: 0000000000000000 R12: ffffc9001bdbfd79
R13: ffffc9000256fd78 R14: ffffc9001aa2fd78 R15: ffff8880b9c424d0
FS: 0000000000000000(0000) GS:ffff8880b9c00000(0063) knlGS:00000000f55b7b40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: ffffc9001bdbfd88 CR3: 000000008b5d9000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
rb_erase_cached include/linux/rbtree.h:126 [inline]
timerqueue_del+0x7f/0x140 lib/timerqueue.c:57
__remove_hrtimer+0xa1/0x2a0 kernel/time/hrtimer.c:1116
__run_hrtimer kernel/time/hrtimer.c:1665 [inline]
__hrtimer_run_queues+0x4ea/0xe50 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
__sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
</IRQ>
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0xc/0x70 kernel/kcov.c:283
Code: 00 00 00 48 89 7c 30 e8 48 89 4c 30 f0 4c 89 54 d8 20 48 89 10 5b c3 0f 1f 80 00 00 00 00 41 89 f8 bf 03 00 00 00 4c 8b 14 24 <89> f1 65 48 8b 34 25 40 f0 01 00 e8 54 f0 ff ff 84 c0 74 4b 48 8b
RSP: 0018:ffffc90019797440 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff8880001373e4 RCX: 0000000000000000
RDX: 0000000000000003 RSI: 0000000000000004 RDI: 0000000000000003
RBP: ffff8881407c547c R08: 0000000000000000 R09: ffffffff840a6804
R10: ffffffff840a69c5 R11: 0000000000000008 R12: 0000000000000004
R13: 0000000000000047 R14: ffff8880001373e0 R15: dffffc0000000000
fast_imageblit drivers/video/fbdev/core/cfbimgblt.c:258 [inline]
cfb_imageblit+0x655/0x1240 drivers/video/fbdev/core/cfbimgblt.c:300
vga_imageblit_expand drivers/video/fbdev/vga16fb.c:1207 [inline]
vga16fb_imageblit+0x681/0x2200 drivers/video/fbdev/vga16fb.c:1260
bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:139 [inline]
bit_putcs+0x6e1/0xd20 drivers/video/fbdev/core/bitblit.c:188
fbcon_putcs+0x35a/0x450 drivers/video/fbdev/core/fbcon.c:1296
do_update_region+0x399/0x630 drivers/tty/vt/vt.c:676
redraw_screen+0x61f/0x740 drivers/tty/vt/vt.c:1035
vc_do_resize+0xe6f/0x1100 drivers/tty/vt/vt.c:1325
fbcon_modechanged+0x393/0x6d0 drivers/video/fbdev/core/fbcon.c:2640
fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:2696
do_fb_ioctl+0x62e/0x690 drivers/video/fbdev/core/fbmem.c:1108
fb_compat_ioctl+0x17e/0x610 drivers/video/fbdev/core/fbmem.c:1307
__do_compat_sys_ioctl+0x1c7/0x290 fs/ioctl.c:964
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203
entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7fbd549
Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f55b75fc EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000004601
RDX: 0000000020000280 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
CR2: ffffc9001bdbfd88
---[ end trace 573584e01bd36498 ]---
RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:173 [inline]
RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:216 [inline]
RIP: 0010:rb_erase+0x5f6/0x1210 lib/rbtree.c:443
Code: e3 fc 0f 84 0c 01 00 00 48 8d 7b 10 48 89 dd 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 84 0a 00 00 <4c> 3b 6b 10 0f 84 37 02 00 00 48 8d 7b 08 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc90000007d88 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: ffffc9001bdbfd78 RCX: 0000000000000000
RDX: 1ffff920037b7fb1 RSI: ffff8880b9c424d0 RDI: ffffc9001bdbfd88
RBP: ffffc9001bdbfd78 R08: ffffc9001bdbfd79 R09: 0000000000000001
R10: ffffffff83f38fdc R11: 0000000000000000 R12: ffffc9001bdbfd79
R13: ffffc9000256fd78 R14: ffffc9001aa2fd78 R15: ffff8880b9c424d0
FS: 0000000000000000(0000) GS:ffff8880b9c00000(0063) knlGS:00000000f55b7b40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: ffffc9001bdbfd88 CR3: 000000008b5d9000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: e3 fc jrcxz 0xfffffffe
2: 0f 84 0c 01 00 00 je 0x114
8: 48 8d 7b 10 lea 0x10(%rbx),%rdi
c: 48 89 dd mov %rbx,%rbp
f: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
16: fc ff df
19: 48 89 fa mov %rdi,%rdx
1c: 48 c1 ea 03 shr $0x3,%rdx
20: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
24: 0f 85 84 0a 00 00 jne 0xaae
* 2a: 4c 3b 6b 10 cmp 0x10(%rbx),%r13 <-- trapping instruction
2e: 0f 84 37 02 00 00 je 0x26b
34: 48 8d 7b 08 lea 0x8(%rbx),%rdi
38: 48 rex.W
39: b8 00 00 00 00 mov $0x0,%eax
3e: 00 fc add %bh,%ah


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